2016 Vol. 32, No. 9

Expert Forum
Phage therapy for bacterial infection of burn
Peng Yizhi, Huang Guangtao
2016, 32(9): 513-516. doi: 10.3760/cma.j.issn.1009-2587.2016.09.001
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With the long-term and widespread use of antibiotics, drug resistance of bacteria has become a major problem in the treatment of burn infection. For treating multidrug resistant bacteria, phage therapy has become the focus of attention. Development of phage therapy to fill the blank of this field in China is extremely urgent.
Burn Infection
Inventory building of phages against extensively drug-resistant Acinetobacter baumannii isolated from wounds of patients with severe burn and related characteristic analysis
Yang Zichen, Deng Liuyang, Gong Yali, Yin Supeng, Jiang Bei, Huang Guangtao, Peng Yizhi, Hu Fuquan
2016, 32(9): 517-522. doi: 10.3760/cma.j.issn.1009-2587.2016.09.002
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Objective To build inventory of phages against extensively drug-resistant Acinetobacter Baumannii isolated from wounds of inpatients of burn ICU and analyze related characteristics. Methods In 2014 and 2015, 131 strains of extensively drug-resistant Acinetobacter Baumannii were isolated from wounds of inpatients of burn ICU from one hospital in Chongqing. In 2015, 98 strains of extensively drug-resistant Acinetobacter Baumannii were isolated from wounds of inpatients of burn ICU from 6 hospitals in Guangdong province. Above-mentioned 229 strains were collected for conducting experiments as follows: (1) Multilocus sequence typing (MLST) of strains isolated from Chongqing and Guangdong province was analyzed. (2) Sewage co-culture method was applied for isolation of phages with above-mentioned strains and sewage from Chongqing and Guangdong province. Numbers of isolated phages and times of successful isolation and unsuccessful isolation were recorded. (3) The most prevalent subtypes of strains from Chongqing and Guangdong province in 2015 were collected, and their phages respectively underwent cross infection with all strains from Chongqing and those from Guangdong province. The lysis ability of phage was observed when phage underwent cross infection with the same subtype of strain or not the same, and the lytic ratio was calculated. (4) Fluid of phage in one type was randomly selected and equally divided into 3 parts, and its titer was determined by double dilution method. Then each part of phage fluid was subdivided into 3 small parts, which were cultured with LB fluid medium and respectively stored under the condition of -20 ℃, 4 ℃, and room temperature. After being stored for 1 month and 2 months, the titer of phage was determined for evaluating stability of phage. Data were processed with Fisher′s exact test, chi-square test, and one-way analysis of variance. Results (1) The major type of strains from Chongqing in 2014 was ST368 (45%, 31/69), and major types of strains from Chongqing in 2015 were ST75 (26%, 16/62) and ST195 (24%, 15/62), while that from Guangdong province in 2015 was ST977 (46%, 45/98). (2) For strains from Chongqing, isolation effect of phage with sewage of Chongqing (8 times of successful isolation with 9 strains of phages and 1 time of unsuccessful isolation) was better than that with sewage of Guangdong province (1 time of successful isolation with 1 strain of phage and 7 times of unsuccessful isolation). For strains from Guangdong province, isolation effect of phage with sewage of Guangdong province (8 times of successful isolation with 6 strains of phages) was better than that with sewage of Chongqing (7 times of unsuccessful isolation with no phage). These differences were statistically significant (P<0.05 or P<0.01). There was no obvious difference in isolation effect of phage between strains from Chongqing with sewage of Chongqing and strains from Guangdong province with sewage of Guangdong province (P>0.05). (3) The ratios of phages of ST75 and ST977 extensively drug-resistant Acinetobacter Baumannii strains lysing the strains with the same type were respectively 13/16 and 8/9, which were obviously higher than those lysing the strains with different type (respectively 11/115 and 3/53, with χ2 values respectively 48.23 and 68.46, P values below 0.001). (4) Compared with that before storage, titer of phage under storage condition of -20 ℃, 4 ℃, and room temperature for 1 month decreased by approximately 1 order of magnitude, and that for 2 months decreased by approximately 2 orders of magnitude. After being stored for 1 month and 2 months, there were no statistically significant differences in titer of phage among 3 storage conditions (with F values respectively 1.29 and 1.07, P values above 0.05). Conclusions This study has successfully built an inventory covering 229 strains of phages of extensively drug-resistant Acinetobacter Baumannii. MLST of extensively drug-resistant Acinetobacter baumannii varies in different area and different time. Phage can be well isolated using sewage with the same source as that of strain. The lysis ability of phage is closely related to the MLST of strains. Inventory of phages should be built according to regional division. Moreover, phage cultured with LB fluid medium shows good stability without special requirements for storage conditions.
Therapeutic effect of phages on extensively drug-resistant Acinetobacter baumannii-induced sepsis in mice
Deng Liuyang, Yang Zichen, Gong Yali, Huang Guangtao, Yin Supeng, Jiang Bei, Peng Yizhi
2016, 32(9): 523-528. doi: 10.3760/cma.j.issn.1009-2587.2016.09.003
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Objective To study the therapeutic effect of phages on extensively drug-resistant Acinetobacter baumannii-induced sepsis in mice. Methods (1) Sixty BALB/c mice were divided into blank control group, sepsis control group, antibiotics treatment group, phage treatment group, and phage control group according to the random number table, with 12 mice in each group. Mice in blank control group were intraperitoneally (the same injection position below) injected with 1 mL normal saline. Mice in sepsis control group, antibiotics treatment group, and phage treatment group were injected with 1 mL extensively drug-resistant Acinetobacter baumannii (the strain was isolated from the blood of a severely burned patient hospitalized in our unit) in the concentration of 5×107 colony-forming unit/mL to reproduce sepsis model. Two hours later, mice in sepsis control group, antibiotics treatment group, and phage treatment group were injected with 1 mL saline, 1 mg/mL imipenem/cilastatin, and 1×108 plaque-forming unit (PFU)/mL phages screened based on above-mentioned Acinetobacter baumannii (the same phages below) respectively. Mice in phage control group were injected with 1 mL phages in the titer of 1×108 PFU/mL. The injection was performed continuously for 7 days in each living mouse, and the survival situation of mice was observed each day to calculate the survival ratio in one week. (2) Another 60 BALB/c mice were grouped and treated as in experiment (1), and the injection was performed continuously for 5 days in each living mouse. On experiment day 2, 4, and 6, 3 mice from each group were selected (if the number of survived mouse in any group was less than 3 at sample collecting, all the survived mice were selected), and blood was drawn to determine white blood cell count (WBC, with 3 samples at each time point in each group). On experiment day 2, blood was drawn from the mice that had their blood taken earlier for bacterial culture, and lung, liver, kidney, and spleen tissue was collected from the same mice. The tissue samples were added to the LB solid medium after being homogenized and diluted for bacterial culture. The content of bacteria was calculated after the bacterial colony number was counted. Data were processed Wilcoxon rank sum test, one-way analysis of variance, LSD test and Kruskal-Wallis rank sum test. Results (1) On experiment day 7, there were 12, 8, 10, and 12 mice survived in blank control group, antibiotics treatment group, phage treatment group, and phage control group respectively, while no mouse survived in sepsis control group. Compared with that in sepsis control group, the survival ratio of mice was significantly higher in the other four groups (with Z values from 55.635 to 106.593, P values below 0.05). The survival ratio of mice in phage treatment group was slightly higher than that in antibiotics treatment group, without statistically significant difference (Z=2.797, P>0.05). (2) On experiment day 2, WBC data of mice in blank control group, phage treatment group, and phage control group were close[respectively (5.60±0.94)×109/L, (5.16±0.36)×109/L, and (5.26±1.89)×109/L], all significantly lower than the datum in sepsis control group[(8.64±0.64)×109/L, P<0.05 or P<0.01], and the WBC data in the latter two groups were significantly lower than the datum in antibiotics treatment group[(7.80±1.76)×109/L, with P values below 0.05]. On experiment day 4, WBC data of mice in antibiotics treatment group, phage treatment group, and phage control group were close, all significantly lower than the datum in blank control group (P<0.05 or P<0.01), and WBC data in the above-mentioned four groups were all lower than the datum in sepsis control group (with P values below 0.01). On experiment day 6, there was no statistically significant difference in WBC among blank control group, antibiotics treatment group, phage treatment group, and phage control group (χ2=4.128, P>0.05). On experiment day 2, respectively 12, 7, and 2 mice were detected as blood bacterial culture-positive in sepsis control group, antibiotics treatment group, and phage treatment group, while no positive result was detected in the other two groups. Positive ratios of blood bacterial culture of mice in blank control group, phage treatment group, phage control group were significantly lower than the ratio in sepsis control group (with χ2 values from -30.000 to 30.000, P values below 0.01). Positive ratio of blood bacterial culture of mice in antibiotics treatment group was significantly higher than that in blank control group or phage control group (with χ2 values respectively 17.500 and -17.500, P values below 0.05). On experiment day 2, except for the kidney tissue of mice in phage treatment group, the bacteria load in each viscus of mice in blank control group, phage treatment group, and phage control group was significantly lower than that in sepsis control group (with χ2 values from -9.000 to 9.000, P values below 0.01). The bacteria load in kidney of mice in antibiotics treatment group was significantly higher than that in blank control group or phage control group (with χ2 values respectively -7.500 and 7.500, P values below 0.05). Conclusions Phages can significantly improve survival ratio, control inflammation response, and effectively clean bacteria in lung, liver, spleen, and kidney in treating extensively drug-resistant Acinetobacter baumannii-induced sepsis in mice.
Analysis of the pathogenic characteristics of 162 severely burned patients with bloodstream infection
Gong Yali, Yang Zichen, Yin Supeng, Liu Meixi, Zhang Cheng, Luo Xiaoqiang, Peng Yizhi
2016, 32(9): 529-535. doi: 10.3760/cma.j.issn.1009-2587.2016.09.004
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Objective To analyze the distribution and drug resistance of pathogen isolated from severely burned patients with bloodstream infection, so as to provide reference for the clinical treatment of these patients. Methods Blood samples of 162 severely burned patients (including 120 patients with extremely severe burn) with bloodstream infection admitted into our burn ICU from January 2011 to December 2014 were collected. Pathogens were cultured by fully automatic blood culture system, and API bacteria identification panels were used to identify pathogen. Kirby-Bauer paper disk diffusion method was used to detect the drug resistance of major Gram-negative and -positive bacteria to 37 antibiotics including ampicillin, piperacillin and teicoplanin, etc. (resistance to vancomycin was detected by E test), and drug resistance of fungi to 5 antibiotics including voriconazole and amphotericin B, etc. Modified Hodge test was used to further identify imipenem and meropenem resistant Klebsiella pneumonia. D test was used to detect erythromycin-induced clindamycin resistant Staphylococcus aureus. The pathogen distribution and drug resistance rate were analyzed by WHONET 5.5. Mortality rate and infected pathogens of patients with extremely severe burn and patients with non-extremely severe burn were recorded. Data were processed with Wilcoxon rank sum test. Results (1) Totally 1 658 blood samples were collected during the four years, and 339 (20.4%) strains of pathogens were isolated. The isolation rate of Gram-negative bacteria, Gram-positive bacteria, and fungi were 68.4% (232/339), 24.5% (83/339), and 7.1% (24/339), respectively. The top three pathogens with isolation rate from high to low were Acinetobacter baumannii, Staphylococcus aureus, and Pseudomonas aeruginosa in turn. (2) Except for the low drug resistance rate to polymyxin B and minocycline, drug resistance rate of Acinetobacter baumannii to the other antibiotics were relatively high (81.0%-100.0%). Pseudomonas aeruginosa was sensitive to polymyxin B but highly resistant to other antibiotics (57.7%-100.0%). Enterobacter cloacae was sensitive to imipenem and meropenem, while its drug resistance rates to ciprofloxacin, levofloxacin, cefoperazone/sulbactam, cefepime, piperacillin/tazobactam were 25.0%-49.0%, and those to the other antibiotics were 66.7%-100.0%. Drug resistance rates of Klebsiella pneumoniae to cefoperazone/sulbactam, imipenem, and meropenem were low (5.9%-15.6%, two imipenem- and meropenem-resistant strains were identified by modified Hodge test), while its drug resistance rates to amoxicillin/clavulanic acid, piperacillin/tazobactam, cefepime, cefoxitin, amikacin, levofloxacin were 35.3%-47.1%, and those to the other antibiotics were 50.0%-100.0%. (3) Drug resistance rates of methicillin-resistant Staphylococcus aureus (MRSA) to most of the antibiotics were higher than those of the methicillin-sensitive Staphylococcus aureus (MSSA). MRSA was sensitive to linezolid, vancomycin, and teicoplanin, while its drug resistance rates to compound sulfamethoxazole, clindamycin, minocycline, and erythromycin were 5.3%-31.6%, and those to the other antibiotics were 81.6%-100.0%. Except for totally resistant to penicillin G and tetracycline, MSSA was sensitive to the other antibiotics. Fourteen Staphylococcus aureus strains were resistant to erythromycin-induced clindamycin. Enterococcus was sensitive to vancomycin and teicoplanin, while its drug resistance rates to linezolid, chloramphenicol, nitrofurantoin, and high unit gentamicin were low (10.0%-30.0%), and those to ciprofloxacin, erythromycin, minocycline, and ampicillin were high (60.0%-80.0%). Enterococcus was fully resistant to rifampicin. (4) Fungi was sensitive to amphotericin B, and drug resistance rates of fungi to voriconazole, fluconazole, itraconazole, and ketoconazole were 7.2%-12.5%. (5) The mortality of patients with extremely severe burn was higher than that of patients with non-extremely severe burn. The variety of infected pathogens in patients with extremely severe burn significantly outnumbered that in patients with non-extremely severe burn (Z=-2.985, P=0.005). Conclusions The variety of pathogen in severely burned patients with bloodstream infection is wide, with the main pathogens as Acinetobacter baumannii, Staphylococcus aureus, and Pseudomonas aeruginosa, and the drug resistance situation is grim. The types of infected pathogen in patients with extremely severe burn are more complex, and the mortality of these patients is higher when compared with that of patients with non-extremely severe burn.
Advances in the research of LuxR family protein in quorum-sensing system of gram-negative bacteria
Chen Zheng, Xiang Jun
2016, 32(9): 536-538. doi: 10.3760/cma.j.issn.1009-2587.2016.09.005
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Quorum sensing (QS) is a cell-density-dependent method for information transmission among bacteria, as well as a mechanism for the bacteria to adapt to environment. LuxR family protein plays a key role in gram-negative bacterial QS system as a kind of transcription regulators and participates in a variety of biological behaviors with LuxI protein and signal molecules, such as bioluminescence, biofilm formation, virulence factors production, and so on. The advances in the research of LuxR family protein in QS system of gram-negative bacteria were summarized in this review.
Advances in the research of treating multi-drug resistant bacterial infections
Peng Yuan, Fu Yuexian
2016, 32(9): 539-541. doi: 10.3760/cma.j.issn.1009-2587.2016.09.006
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It is imperative to research the treatment strategy for infections caused by multi-drug resistant (MDR) bacteria, as there are increasing reports showing that more and more patients are decimated by the infections of MDR bacteria and the development of antimicrobial drugs is in downturn. Current researches mainly focus on the following three aspects: developing new antimicrobial agents with the aid of basic scientific achievements in finding new antibacterial targets, achieving antimicrobial purpose by specific lysis of host bacteria with phages of high specificity, and killing bacteria potently by destroying its cytomembrane using broad-spectrum antimicrobial peptides.
2016, 32(9): 528-528. doi: 10.3760/cma.j.issn.1009-2587.2016.09.101
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2016, 32(9): 535-535. doi: 10.3760/cma.j.issn.1009-2587.2016.09.102
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2016, 32(9): 548-548. doi: 10.3760/cma.j.issn.1009-2587.2016.09.103
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2016, 32(9): 559-559. doi: 10.3760/cma.j.issn.1009-2587.2016.09.104
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2016, 32(9): 566-568. doi: 10.3760/cma.j.issn.1009-2587.2016.09.011
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2016, 32(9): 569-571. doi: 10.3760/cma.j.issn.1009-2587.2016.09.012
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Original Article
Phase Ⅳ clinical trial for external use of recombinant human granulocyte-macrophage colony-stimulating factor gel in treating deep partial-thickness burn wounds
Liu Jian, Liao Zhenjiang, Zhang Qin
2016, 32(9): 542-548. doi: 10.3760/cma.j.issn.1009-2587.2016.09.007
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Objective To evaluate the clinical efficacy and safety of external use of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) gel on deep partial-thickness burn wounds. Methods Sixty-eight hospitals in our country including our unit performed a phase Ⅳ clinical trial for rhGM-CSF gel in patients (conforming to the study criteria) with deep partial-thickness burn wounds from November 2010 to July 2012. Multicenter, randomized, positive-homogenous-controlled, and open trial method was used in the trial, and patients from 10 hospitals were grouped into the positive-homogenous-controlled trial, while patients from the other 58 hospitals were grouped into open trial. (1) Controlled trial. Patients were divided into rhGM-CSF group and conventional treatment group (CT) with the ratio of 1∶1 according to the stratified randomization method. Wounds of patients in rhGM-CSF group were coated with rhGM-CSF gel, and wounds of patients in group CT were covered by gauze with iodophor. Scores of wound exudate and wound edge response before treatment and on treatment day (TD) 2, 4, 8, 10, 14, 20, and 28 were conventionally evaluated. Wound healing rates on TD 8, 10, 14, 20, and 28 were calculated. Complete wound healing time and overall efficiency including cure, excellence, progress, and invalid situation on TD 28 were recorded. Safety indexes including vital signs and laboratory test indexes before and during treatment, and adverse reactions during treatment were observed. (2) Open trial. Wounds of patients in this trail were all coated with rhGM-CSF gel. Complete wound healing time, overall efficiency, and safety indexes of patients were recorded as in controlled trial. Data were processed with CMH-χ2 test, Fisher′s exact test, signed rank sum test, paired t test, Log-Rank test, and Wilcoxon rank sum test. Results (1) Controlled trail. A total of 366 patients from 10 hospitals were included in this trial, and 358 cases with 177 cases in rhGM-CSF group and 181 cases in group CT finished the trial. There were no statistically significant differences in gender, age, injury characteristics, and combined medication situation between patients in two groups (χ2=1.510, with t values from 0.458 to 0.820, P values above 0.05). Scores of wound exudate of patients in two groups were similar before treatment and on TD 2, 20, and 28 (t=0.420, with Z values from 0.735 to 1.939, P values above 0.05). Scores of wound exudate of patients in rhGM-CSF group were significantly lower than those in group CT on TD 4, 8, 10, and 14 (with Z values from 2.054 to 2.580, P values below 0.05). Scores of wound edge response of patients in two groups were similar before treatment and on each TD (t=0.340, with Z values from -1.147 to 1.874, P values above 0.05). Wound healing rate of patients in rhGM-CSF group was significantly higher than that in group CT on each TD (with Z values from 2.630 to 5.235, P values below 0.01). The complete wound healing time of patients in rhGM-CSF group was (16.93±0.40) d, which was significantly shorter than that in group CT[(19.88±0.41) d, χ2=26.732, P<0.001]. At last, 171 (96.61%) patients were completely cured in rhGM-CSF group, while excellence, progress, and invalid results were achieved in 3 (1.69%), 1 (0.56%), and 2 (1.13%) patients, respectively. Whereas, 161 (88.95%) patients were completely cured in group CT, while excellence, progress, and invalid results were achieved in 11 (6.08%), 5 (2.76%), and 4 (2.12%) patients, respectively. Total efficacy of patients in rhGM-CSF group was significantly higher than that in group CT (χ2=5.784, P<0.05). Levels of vital signs and laboratory test indexes of patients in two groups before and during treatment were similar. There were no statistically significant differences in adverse reaction or drug-related adverse reaction between patients in two groups during treatment (with P values above 0.05). (2) Open trial. A total of 2 380 patients were enrolled in, and 2 329 patients finished the trial. The complete wound healing time of patients was (16.28±0.10)d. At last, 2 257 (96.91%) patients were totally cured, while excellence, progress, and invalid results were achieved in 36 (1.55%), 16 (0.69%), and 20 (0.86%) patients, respectively. Vital signs and laboratory test indexes of patients before and during treatment were similar. The drug-related adverse reaction was observed in 44 patients (1.89%). Conclusions External use of rhGM-CSF gel on deep partial-thickness burn wounds can promote wound healing and is safe for clinical use.
Efficacy of a hydrosurgery system applied in the debridement of extensive residual wounds of patients with severe burn
Liu Gongcheng, Kan Zhaohui, Sheng Jiajun, Li Haihang, Li Lei, Sun Yu, Ji Shizhao, Zhu Shihui
2016, 32(9): 549-554. doi: 10.3760/cma.j.issn.1009-2587.2016.09.008
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Objective To explore the efficacy of a hydrosurgery system applied in the debridement of extensive residual wounds of patients with severe burn prospectively. Methods Seventy-six severely burned patients with extensive residual wounds after treatment were admitted into Department of Burn Surgery of Changhai Hospital of the Second Military Medical University from May 2012 to November 2015. The patients were divided into hydrosurgery system debridement group (HD, n=34) and traditional debridement group (TD, n=42) according to the random number table, and their residual wounds were debrided by a hydrosurgery system and conventional surgical instruments respectively. The wounds of patients in two groups were repaired with stamp-like grafts made from split-thickness autoskin after debridement. Second time of debridement and skin grafting as above was performed if necessary. The time used in debriding 1% TBSA wound in the first surgery, positive rate of bacterial culture of wound exudate on post first surgery day (PFSD) 3, survival rate of skin grafts on PFSD 7, second debridement rate, and wound healing time of patients in two groups were compared. Data were processed with two independent-sample t test and chi-square test. Results The time used in debriding 1% TBSA wound of patients in the first surgery in group HD was (1.2±0.3) min, which was significantly shorter than that in group TD[(1.9±0.4) min, t=-9.098, P<0.001]. On PFSD 3, positive rate of bacterial culture of wound exudate of patients in group HD was 11.76% (4/34), which was significantly lower than that in group TD[38.10% (16/42), χ2=6.718, P=0.010]. On PFSD 7, the survival rate of skin grafts of patients in group HD was (90±8)%, which was significantly higher than that in group TD[(83±15)%, t=2.334, P=0.022]. The second debridement rate of patients in group HD was 5.88% (2/34), which was significantly lower than that in group TD[23.81% (10/42), χ2=4.542, P=0.033]. The wound healing time of patients in group HD was (10.6±1.5) d, which was significantly shorter than that in group TD[(13.3±2.5) d, t=-5.442, P<0.001]. Conclusions The hydrosurgery system applied in the debridement of extensive residual wounds of patients with severe burn is thorough and highly efficient, which is beneficial to improving the survival rate of skin grafts and accelerating wound healing.
Influence of covering of auto-crosslinked sodium hyaluronate gel in combination with xenogenic acellular dermal matrix on healing of full-thickness skin defect wound in pig
Qiu Yuxuan, Zhang Guoan, Wan Jiangbo, Zhao Xiaozhuo
2016, 32(9): 555-559. doi: 10.3760/cma.j.issn.1009-2587.2016.09.009
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Objective To explore the influence of covering of auto-crosslinked sodium hyaluronate gel in combination with xenogenic acellular dermal matrix (ADM) on healing of full-thickness skin defect wound in pig. Methods Totally four 10 cm×10 cm full-thickness skin defect wounds were reproduced symmetrically on both sides of spine on the back of each one of the six Chinese experimental minipigs. After autologous microskin grafting, the 4 wounds in each pig were divided into 4 groups according to the random number table, with 6 wounds in each group. Wounds in allogenic skin group (AS) were covered by full-thickness skin from one (not the recipient) of the 6 pigs; wounds in xenogenic skin group (XS) were covered by full-thickness skin of sheep; wounds in xenogenic ADM group (XA) were covered by ADM of sheep; wounds in combination group (C) were covered by ADM of sheep combined with auto-crosslinked sodium hyaluronate gel. The wounds were bound up with pressure, and the dressing was changed once every 7 days. On post surgery day (PSD) 7, 14, 21, 28, 35, and 42 when changing dressing, the condition of wounds and the exfoliation of the covering on microskin were observed, and the complete exfoliation time of the covering was recorded. On PSD 28, 35, and 42, the wound healing rate was calculated. Data were processed with one-way analysis of variance and SNK test. Results (1) On PSD 7, no fluid appeared under the covering of wounds in groups AS and C, while plenty of fluid appeared under the covering of wounds in groups XS and XA. From PSD 14 to 35, most of the full-thickness skin of pig in group AS did not exfoliate. All the full-thickness skin of sheep in group XS exfoliated, leaving a lot of crusts on the surface of the wounds on PSD 14. Most of the ADM of sheep in group XA separated from the wound with the crusts turning dry and exfoliating on PSD 14. All the ADM of sheep exfoliated with most of the wounds healed in group C on PSD 35. On PSD 42, all the full-thickness skin of pig in group AS exfoliated, leaving most of the wounds unhealed; all the crusts exfoliated and the majority of wounds were healed in group XS and XA group; all the wounds in group C were healed. (2) Compared with that in group C[(32.7±3.3) d], the complete exfoliation time of the covering was obviously shorter in group XS[(15.2±4.8) d]and group XA[(22.2±6.3) d], with P values below 0.05, while the complete exfoliation time of the covering in group AS[(44.8±2.7) d]was obviously longer (P<0.05). (3) On PSD 28, 35, and 42, the wound healing rates in groups XS and XA[(21.2±2.6)%, (51.4±2.4)%, (89.6±2.8)%, and (23.7±3.4)%, (53.6±6.3)%, (91.3±4.9)%, respectively]were obviously lower than those in group C[(35.1±3.4)%, (62.1±6.7)%, (98.8±1.0)%, respectively, with P values below 0.05]. On PSD 42, the wound healing rate in group AS[(44.0±3.8)%]was significantly lower than the rates in the other 3 groups (with P values below 0.05). Conclusions Auto-crosslinked sodium hyaluronate gel combined with ADM of sheep used as covering of microskin grafts on full-thickness wound in pig can lengthen the persistence time of ADM of sheep on the wound, as well as promote wound healing.
Effect of low-energy 633 nm red light stimulation on proliferation and reactive oxygen species level of human epidermal cell line HaCaT
Chen Zhiyong, Li Dongliang, Duan Xiaodong, Peng Daizhi
2016, 32(9): 560-565. doi: 10.3760/cma.j.issn.1009-2587.2016.09.010
Abstract:
Objective To investigate the changes of proliferative activity and reactive oxygen species level of human epidermal cell line HaCaT after being irradiated with low-energy 633 nm red light. Methods Irradiation distance was determined through preliminary experiment. HaCaT cells were conventionally sub-cultured with RPMI 1640 culture medium containing 10% fetal calf serum, 100 U/mL penicillin, and 100 μg/mL streptomycin. Cells of the third passage were used in the following experiments. (1) Cells were divided into blank control group and 0.082, 0.164, 0.245, 0.491, 1.472, 2.453, 4.910, and 9.810 J/cm2 irradiation groups according to the random number table, with 3 wells in each group. Cells in blank control group were not irradiated, while cells in the latter 8 irradiation groups were irradiated with 633 nm red light for 10, 20, 30, 60, 180, 300, 600, and 1 200 s in turn. Cells were reirradiated once every 8 hours. After being irradiated for 48 hours (6 times) in irradiation groups, the proliferative activity of cells in 9 groups was determined with cell counting kit 8 and microplate reader (denoted as absorbance value). (2) Another batch of cells were grouped and irradiated as in experiment (1). After being irradiated for once in irradiation groups, cells in 9 groups were conventionally cultured for 60 min with detection reagent of reactive oxygen species. At post culture minute (PCM) 0 (immediately), 30, 60, and 120, reactive oxygen species level of cells was determined with microplate reader (denoted as absorbance value). (3) Another batch of cells were divided into blank control group, 0.082, 0.491, 2.453, and 9.810 J/cm2 irradiation groups, and positive control group. Cells in blank control group and positive control group were not irradiated (positive control reagent of reactive oxygen species was added to cells in positive control group), and cells in irradiation groups were irradiated as in experiment (1) for once. The expression of reactive oxygen species in cells of each group was observed by confocal laser scanning microscope. Data were processed with one-way analysis of variance, analysis of variance for repeated measurement, and t test. Results (1) Irradiation distance was 10 cm. Proliferative activity of cells in blank control group and 0.082, 0.164, 0.245, 0.491, 1.472, 2.453, 4.910, and 9.810 J/cm2 irradiation groups was 1.000, 1.116±0.031, 1.146±0.016, 1.162±0.041, 1.179±0.016, 1.207±0.016, 1.247±0.040, 1.097±0.059, and 0.951±0.118, respectively. Compared with that in blank control group, proliferative activity of cells in 0.082-2.453 J/cm2 irradiation groups was significantly higher (with t values from -22.803 to -6.779, P values below 0.05). Proliferative activity of cells in 4.910 and 9.810 J/cm2 irradiation groups was similar to that in blank control group (with t values respectively -2.854 and 0.711, P values above 0.05). (2) Compared with that in blank control group, reactive oxygen species level of cells was significantly enhanced at PCM 0 and 30 in 0.164-2.453 J/cm2 irradiation groups (with t values from -12.453 to -4.684, P<0.05 or P<0.01), while that showed no significant change in 0.082, 4.910, and 9.810 J/cm2 irradiation groups (with t values from -3.925 to -0.672, P values above 0.05). Compared with that in blank control group, reactive oxygen species level of cells was significantly enhanced at PCM 60 in 0.082-2.453 J/cm2 irradiation groups (with t values from -11.387 to -4.717, P<0.05 or P<0.01). Compared with that in blank control group, reactive oxygen species level of cells was significantly enhanced at PCM 120 in 0.491-2.453 J/cm2 irradiation groups (with t values from -10.657 to -6.644, P<0.05 or P<0.01). (3) Compared with that in blank control group, the expression of reactive oxygen species of cells was increased in 0.082, 0.491, and 2.453 J/cm2 irradiation groups and positive control group. The expression of reactive oxygen species of cells in 9.810 J/cm2 irradiation group was attenuated when compared with the expressions in the other irradiation groups. Reactive oxygen species expressed in mitochondria of cells in each group. Conclusions Low-energy 633 nm red light can enhance the proliferation of human epidermal cell line HaCaT, and the effect is closely related to the increase of reactive oxygen species produced by mitochondria after being stimulated by red light irradiation.
Review
Current situation and reflection on the treatment of relative low-heat burns
Lei Wanjun, Jing Aihua
2016, 32(9): 572-574. doi: 10.3760/cma.j.issn.1009-2587.2016.09.013
Abstract:
Relative low-heat burn can cause primary and secondary damage, and its basic research and clinical studies need to be carried out urgently. In this article, we review content related to relative low-heat burn, including pathogenesis, epidemiological characteristics, and prevention and treatment based on retrieving relevant domestic literature.
Application of a hydrosurgery system in debridement of various types of burn wounds
Li Mengyun, Mao Yuangui, Guo Guanghua, Liu Dewu
2016, 32(9): 574-576. doi: 10.3760/cma.j.issn.1009-2587.2016.09.014
Abstract:
Burn wound healing is closely associated with the depth of wound and early debridement. The traditional ways of debridement have certain limitations and often result in poor appearance and function of repaired area. At present, the hydrosurgery system has been applied clinically in burn field. This paper summarizes advantages and disadvantages of application of the hydrosurgery system in debridement of burn wound with different depths, different periods, extraordinary region, and uncommon agent.