2018 Vol. 34, No. 4

Expert Forum
Lay emphasis on circulatory state research after fluid resuscitation in early burns
Zhang Qin, Tang Yaoqing
2018, 34(4): 193-196. doi: 10.3760/cma.j.issn.1009-2587.2018.04.001
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In this article, we discuss future development of circulatory state research after fluid resuscitation in early burns from its history and difficulties confronted. We believe that the Chinese fluid resuscitation formula to predict initial volume of fluid infusion of extensive burn patients is still useful and effective, while we should attach more importance to advances in the research of burn pathophysiology, basic theory and clinical practices of Chinese fluid resuscitation formula, so as to provide strategy of fluid resuscitation in early burns for international burn world. We should know clearly circulatory state of patients from circulatory driving force, microcirculation, and cell oxygenation. Besides, multidisciplinary cooperation should be strengthened, such as promoting communication and technological convergence between burn discipline and critical care discipline, to make preparation for future of intelligent and individualized fluid resuscitation.
2018, 34(4): 196-196. doi: 10.3760/cma.j.issn.1009-2587.2018.04.101
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2018, 34(4): 196-196. doi: 10.3760/cma.j.issn.1009-2587.2018.04.103
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2018, 34(4): 196-196. doi: 10.3760/cma.j.issn.1009-2587.2018.04.102
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2018, 34(4): 202-202. doi: 10.3760/cma.j.issn.1009-2587.2018.04.104
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2018, 34(4): 240-242. doi: 10.3760/cma.j.issn.1009-2587.2018.04.009
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Critical Burn
Observation on safety and effects of analgesic and sedative treatment in severely burned patients during shock stage
Li Rubing, Chen Qian, Zhang Hongyan, Deng Hong′ao, Guo Guanghua, Mao Yuangui, Fu Zhonghua
2018, 34(4): 197-202. doi: 10.3760/cma.j.issn.1009-2587.2018.04.002
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Objective To observe the safety and effects of application of analgesic and sedative drugs in severely burned patients during shock stage. Methods One hundred and eighty patients with severe burns, conforming to the study criteria, were admitted to our unit from August 2014 to August 2016. Patients were divided into analgesia and sedation group and control group according to whether receiving analgesic and sedative treatment or not, with 90 cases in each group. Patients in control group received conventional treatment, while those in analgesia and sedation group received analgesic and sedative treatment for 24 hours besides conventional treatment. Before and at drug administration hour 2, 8, 16, and 24, pain degree of patients in two groups was scored by visual analogue scale (VAS). At drug administration hour 2, 8, 16, and 24, sedation degree of patients in two groups was scored by richmond agitation sedation scale, and the success rate of sedation was calculated. Mental state of patients within 24 hours of drug administration was observed, while pulse oxygen saturation (SpO2), respiratory rate, heart rate, and blood pressure were observed and dynamically evaluated every 2 hours. The accidental extubation, tachycardia, hypertension, hypoxia, bradycardia, hypotension, urinary retention, and respiratory depression of patients within 24 hours of drug administration were monitored and recorded. Data were processed with analysis of variance for repeated measurement, one-way analysis of variance, t test, chi-square test, Wilcoxon rank sum test, and Fisher′s exact probability test. Results (1) The VAS scores of patients in two groups were close before drug administration (t=0.675, P>0.05). The VAS scores of patients in analgesia and sedation group at drug administration hour 2, 8, 16, and 24 were (3.8±0.4), (3.9±0.6), (3.9±0.5), and (3.9±0.9) points, respectively, significantly lower than (6.0±0.9), (6.0±1.2), (6.2±0.6), and (6.3±0.4) points in control group (t=0.785, 0.730, 0.805, 0.895, P<0.05). The success rate of sedation of patients in analgesia and sedation group at drug administration hour 2, 8, 16, and 24 were 91.1% (82/90), 86.7% (78/90), 93.3% (84/90), and 90.0% (81/90), respectively, significantly higher than 7.8% (7/90), 6.7% (6/90), 14.4% (13/90), and 5.6% (5/90) in control group (Z=8.035, 7.946, 8.129, 8.014, P<0.05). (2) The respiratory rate of patients in analgesia and sedation group at drug administration hour 8, 16, and 24 were (15.78±0.69), (16.08±0.59), and (16.21±0.20) times per minute, and the heart rate were (87±9), (83±7), and (76±9) times per minute, respectively, significantly lower than (16.80±0.81), (17.09±0.50), and (17.02±0.61) times per minute and (89±8), (86±7), and (85±6) times per minute in control group (t=7.655, 7.022, 6.536, -6.931, -7.053, -10.196, P<0.01). There were no statistically significant difference in SpO2, systolic blood pressure, and diastolic blood pressure before and at drug administration hour 2, 8, 16, and 24 between the two groups (t=3.417, -2.894, -6.501, -3.719, -4.573, 2.336, 3.315, 0.942, -1.583, 1.907, 1.147, -0.968, 0.931, -1.682, 1.076, P>0.05). (3) The rates of respiratory depression, hypoxia, bradycardia, urinary retention, and hypotension of patients in the two groups were close (χ2=0.310, P>0.05). The rates of hypertension, accidental extubation, and tachycardia of patients in analgesia and sedation group were significantly lower than those in control group (χ2=16.364, 5.143, 73.309, P<0.05 or P<0.01). Conclusions Proper application of analgesic and sedative drugs in severely burned patients during shock stage has good clinical effect with low incidence rates of complications.
Influencing factors and clinical significance of severe hypocalcemia in patients with extremely severe burns in early stage
Wu Jing, Zhang Qin, Liu Jian, Tang Jiajun, Zheng Jiexin
2018, 34(4): 203-207. doi: 10.3760/cma.j.issn.1009-2587.2018.04.003
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Objective To analyze the influencing factors and clinical significance of severe hypocalcemia in patients with extremely severe burns in early stage. Methods Clinical data of 142 patients with extremely severe burns admitted to our wards from January 2010 to July 2015, conforming to the study criteria, were retrospectively analyzed. (1) The incidence of hypocalcemia and severe hypocalcemia on admission were calculated. (2) Patients were divided into the male group (n=113) and the female group (n=29) according to gender. The levels of serum calcium of patients whose age more than 55 years old and less than or equal to 55 years old in the two groups were compared with t test. (3) Patients were divided into severe hypocalcemia group (n=52) and non-severe hypocalcemia group (n=90) according to the level of serum calcium on admission. The data including gender, age, flame burn, total burn area, inhalation injury, admission time, the pH value, and the albumin level of patients on admission between two groups were compared with chi-square test or t test. Indexes with P<0.1 between two groups were selected, and multivariate logistic regression analysis was conducted to screen the influencing factors of severe hypocalcemia in patients with extremely severe burns in early stage. (4) According to the prognosis, patients were divided into survival group (n=112) and non-survival group (n=30). The data including gender, age, flame burn, total burn area, inhalation injury, admission time, the level of serum calcium, the pH value, and the albumin level of patients on admission between two groups were compared with chi-square test or t test. Indexes with P<0.1 between two groups were selected, and multivariate Cox regression analysis was conducted to screen the influencing factors of prognosis of patients with extremely severe burns. Results (1) The incidence of hypocalcemia on admission was 97.2% (138/142), and patients diagnosed as severe hypocalcemia accounted for 36.6% (52/142). (2) In the male group, the level of serum calcium of patients with age more than 55 years old was (1.84±0.19) mmol/L, which was close to (1.88±0.21) mmol/L of patients with age less than or equal to 55 years old within the same group and (1.96±0.13) mmol/L of patients with age more than 55 years old in the female group (t=0.833, 1.560, P>0.05). In the female group, the level of serum calcium of patients with age less than or equal to 55 years old was (1.78±0.19) mmol/L, which was significantly lower than that of patients with age less than or equal to 55 years old in the male group and that of patients with age more than 55 years old in the female group (t=-2.197, -2.472, P<0.05). (3) Compared with those of patients in severe hypocalcemia group, the total burn area and the proportion of inhalation injury of patients in non-severe hypocalcemia group were obviously smaller (t=2.379, χ2 =13.410, P<0.05 or P<0.01), and the admission time was obviously earlier (t=2.675, P<0.01), while the albumin level was obviously higher (t=-6.163, P<0.01). There were no statistically significant differences between patients of the two groups in gender, flame burn, age, and the pH value on admission (χ2=1.869, 2.850, t=-0.578, 0.645, P>0.05). Multivariate logistic regression analysis showed that only the albumin level on admission was the independent influencing factor of severe hypocalcemia in patients with extremely severe burns (with odds ratio 1.179, 95% confidence interval 1.092-1.273, P<0.01). (4) Compared with those of patients in non-survival group, the total burn area and the proportion of inhalation injury in survival group were smaller (t=-5.515, χ2=27.573, P<0.05 or P<0.01), while the pH value and the albumin level on admission were higher (t=2.208, 3.321, P<0.05 or P<0.01). There were no statistically significant differences between patients of the two groups in gender, flame burn, age, admission time, and the level of serum calcium on admission (χ2=0.198, 2.545, t=-1.316, -1.397, 1.857, P>0.05). Multivariate Cox regression analysis showed that total burn area and inhalation injury were the independent risk factors to predict prognosis of patients with extremely severe burns (with relative risk 1.066 and 4.081, 95% confidence interval 1.023-1.110 and 1.144-14.559, P<0.05 or P<0.01), but the pH value and levels of albumin and serum calcium were not independent risk factors to predict prognosis of patients with extremely severe burns (with relative risk 0.003, 1.025, and 0.634, 95% confidence interval <0.001-1.183, 0.956-1.099, and 0.055-7.321, P>0.05). Conclusions The level of serum calcium of the majority of patients with extremely severe burns on admission is decreasing significantly, especially the female patients less than or equal to 55 years old. Compared with non-severe hypocalcemia patients, patients with severe hypocalcemia are with larger total burn area, higher proportion of inhalation injury, later admission time, and lower albumin level on admission. However, only the albumin level on admission is the independent influencing factor of severe hypocalcemia in patients with extremely severe burns. And the level of serum calcium on admission can not predict the prognosis of patients with extremely severe burns.
Dynamic variation trend and prognostic value of bronchial wall thickness in severely burned patients combined with inhalation injury
Wang Xin, Zhang Xuening, Wu Menglin, Jia Licong, Xie Li′na, Meng Yue, Feng Shihai, Ma Wei
2018, 34(4): 208-213. doi: 10.3760/cma.j.issn.1009-2587.2018.04.004
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Objective To explore the dynamic variation trend of bronchial wall thickness (BWT) in severely burned patients combined with inhalation injury, and to determine the value of BWT to prognosis of patients. Methods Forty-three severely burned patients with inhalation injury hospitalized in Intensive Burn Department of the Affiliated Hospital of Nankai University (Tianjin No.4 Hospital) from July to November 2016, conforming to the study criteria, were divided into survival group (n=27) and death group (n=16) according to the prognosis of patients within 14 days after admission. All patients underwent fiberoptic bronchoscopy and inhalation injury rating based on abbreviated injury scale at admission. High resolution CT examination was performed in patients of two groups at admission and 24 h post admission, 3, 7, and 14 d post admission to measure the BWT of right superior lobar bronchus trunk opening. Receiver operating characteristic curves of rating of inhalation damage at admission and BWT at admission were drawn to evaluate the predictive value for death of 43 patients. Data were processed with chi-square test, independent sample t test, Wilcoxon rank sum test, analysis of variance for repeated measurement and least-significant difference-t test. Results (1) The numbers of patients rated as 0, 1, 2, 3, and 4 grade for inhalation injury in survival group and death group were 0, 19, 6, 2, and 0, and 0, 2, 7, 7, and 0, respectively. There were statistically significant differences between the two groups (Z=-3.79, P<0.01). (2) BWT of patients in death group at admission and 24 h post admission, 3, 7, and 14 d post admission was respectively (2.72±0.26), (3.18±0.22), (2.98±0.18), (2.29±0.17), and (1.45±0.21) mm, which was significantly larger than (2.24±0.15), (2.49±0.15), (1.51±0.17), (1.04±0.16), and (1.01±0.13) mm in survival group (t=7.55, 12.14, 27.11, 19.99, 7.11, P<0.01). BWT of patients in survival group and death group at 24 h post admission, 3, 7, and 14 d post admission showed statistically significant difference when compared with that at admission within the corresponding group (t=5.97, 16.63, 28.21, 38.57, 5.34, 3.31, 4.39, 6.48, P<0.01). BWT of patients in survival group and death group on 3, 7, and 14 d post admission was significantly smaller than that at 24 h post admission within the corresponding group (t=22.27, 34.02, 45.03, 2.77, 10.53, 10.59, P<0.01). BWT of patients in survival group and death group on 7 and 14 d post admission was significantly smaller than that on 3 d post admission within the corresponding group (t=10.49, 18.26, 9.57, 11.44, P<0.01). BWT of patients in survival group and death group on 14 d post admission was significantly smaller than that on 7 d post admission within the corresponding group (t=6.97, 6.15, P<0.01). (3) The total areas under ROC curves of inhalation injury rating at admission and BWT at admission for predicting death of 43 patients were 0.880 and 0.956, respectively (with 95% confidence intervals 0.768-0.991, 0.882-1.000, P<0.05). Grade 1.5 and 2.75 mm were respectively chosen as the optimal threshold values of inhalation injury rating at admission and BWT at admission, with sensitivity of 87.50%, 83.33% and specificity of 77.78%, 96.00%, respectively. Conclusions The BWT of survived and dead patients with severe burn and inhalation injury increases significantly post burn, while the BWT of survived patients restores to normal level faster. BWT can be used to assess the severity of inhalation injury and to predict death in severely burned patients combined with inhalation injury.
Original Article
Effects of short chain fatty acid on barrier disruption of human intestinal epithelial cell induced by endotoxin/lipopolysaccharide and the related mechanism
Feng Yanhai, Huang Yalan, Wang Pei, Wang Fengjun
2018, 34(4): 214-218. doi: 10.3760/cma.j.issn.1009-2587.2018.04.005
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Objective To investigate the effects of short chain fatty acid (SCFA) on barrier disruption of human intestinal epithelial cell induced by endotoxin/lipopolysaccharide (LPS) and the related mechanism. Methods The human intestinal epithelial cell line Caco-2 was used to reproduce monolayer-cells. Cells were divided into control group, LPS group, and SCFA+ LPS group according to the random number table. Cells in control group were only routinely cultured with DMEM medium. Cells in LPS group were cultured with DMEM medium and LPS with final mass concentration of 10 μg/mL. Cells in SCFA+ LPS group were cultured with DMEM medium, LPS and SCFA (consisting of 0.5 mmol/L acetate, 0.01 mmol/L propionate, and 0.01 mmol/L butyrate) with final mass concentration of 10 μg/mL. At post culture hour (PCH) 0, 1, 2, 6, 12, and 24, transepithelial electrical resistance (TER) of cells was determined with an ohmmeter, with sample number of 72. Another portion of cells were divided and treated as above, and then Western blotting was employed to detect the protein expressions of zonula occludens 1 (ZO-1), occludin, and claudin-1 at PCH 24, with sample number of 6. Another portion of cells were divided and treated as above and then immunofluorescence was used to observe cellular morphology and distribution of ZO-1. Data were processed with analysis of variance of factorial design, one-way analysis of variance, least-significant difference test, and Bonferroni correction. Results (1) Compared with that in control group, TER of cells in LPS group was significantly reduced from PCH 1 to 24 (P<0.01), while TER of cells in SCFA+ LPS group showed no obvious change (P>0.05). TER of cells in SCFA+ LPS group was significantly higher than that in LPS group from PCH 1 to 24 (P<0.01). (2) Compared with the protein expressions of ZO-1, occludin, and claudin-1 of cells in control group (1.25±0.10, 1.17±0.04, and 1.24±0.20), those of cells in LPS group (0.74±0.23, 0.76±0.11, and 0.77±0.11) at PCH 24 were significantly decreased (P<0.05), while those of cells in SCFA+ LPS group (1.23±0.46, 1.05±0.09, and 1.01±0.13) showed no significant differences (P>0.05). Protein expressions of occludin and claudin-1 of cells in SCFA+ LPS group were significantly higher than those in LPS group at PCH 24 (P<0.05). Protein expression of ZO-1 of cells in SCFA+ LPS group was higher than that in LPS group at PCH 24 with no significant difference (P>0.05). (3) At PCH 24, cells in control group were compact in arrangement with pebble-like appearance, and ZO-1 was distributed smoothly and continuously along the cell membrane. In LPS group, cells were sparse in arrangement with change in appearance, and ZO-1 was distributed uncontinuously along the cell membrane with curls and breaks. In SCFA+ LPS group, the appearance of cells and distribution of ZO-1 were remarkably ameliorated compared with those in LPS group. Conclusions SCFA can alleviate the barrier disruption of human intestinal epithelial cell induced by LPS through interdicting the abnormal distribution of ZO-1 and decrease of TER and tight junction proteins′ expressions.
Effects of exogenous high mobility group protein box 1 on angiogenesis in ischemic zone of early scald wounds of rats
Dai Lei, Guo Xing, Huang Haijun, Liao Xiaomei, Luo Xingqian, Li Dan, Zhou Hong, Gao Xiaochun, Tan Meiyun
2018, 34(4): 219-224. doi: 10.3760/cma.j.issn.1009-2587.2018.04.006
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Objective To observe effects of exogenous high mobility group protein box 1 (HMGB1) on angiogenesis in ischemic zone of early scald wounds of rats. Methods Thirty-six Sprague-Dawley rats were divided into HMGB1 group and simple scald (SS) group according to the random number table, with 18 rats in each group. Comb-like copper mould was placed on the back of rats for 20 s after being immersed in 100 ℃ hot water for 3 to 5 min to make three ischemic zones of wound. Immediately after scald, rats in HMGB1 group were subcutaneously injected with 0.4 μg HMGB1 and 0.1 mL phosphate buffer solution (PBS), and rats in SS group were subcutaneously injected with 0.1 mL PBS from boarders of ischemic zone of scald wound. At post scald hour (PSH) 24, 48, and 72, 6 rats in each group were collected. Protein expressions of vascular endothelial growth factor (VEGF) in ischemic zone of wound at PSH 24, 48, and 72 and protein expressions of CD31 in ischemic zone of wound at PSH 48 and 72 were detected by immunohistochemistry. The number of microvessel in CD31 immunohistochemical sections of ischemic zone of wound at PSH 48 and 72 was calculated after observing by the microscope. The mRNA expressions of VEGF and CD31 in ischemic zone of wound were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction at PSH 24, 48, and 72. Data were processed with analysis of variance of factorial design, t test, and Bonferroni correction. Results (1) At PSH 24, 48, and 72, protein expressions of VEGF in ischemic zone of wound of rats in HMGB1 group were significantly higher than those of rats in SS group (t=7.496, 4.437, 5.402, P<0.05 or P<0.01). At PSH 48 and 72, protein expressions of CD31 in ischemic zone of wound of rats in HMGB1 group were 0.038 8±0.007 9 and 0.057 7±0.001 2 respectively, significantly higher than 0.013 4±0.004 9 and 0.030 3±0.004 0 of rats in SS group (t=10.257, 15.055, P<0.01). (2) At PSH 48 and 72, the number of microvessel in ischemic zone of wound of rats in HMGB1 group was obviously more than that of rats in SS group (t=3.536, 4.000, P<0.05). (3) At PSH 24, 48, and 72, mRNA expressions of VEGF in ischemic zone of wound of rats in HMGB1 group were significantly higher than those of rats in SS group (t=4.406, 3.821, 3.356, P<0.05). At PSH 24 and 48, mRNA expressions of CD31 in ischemic zone of wound of rats in HMGB1 group were significantly higher than those of rats in SS group (t=4.113, 3.466, P<0.05). At PSH 72, mRNA expressions of CD31 in ischemic zone of wound of rats in 2 groups were close (t=0.010, P>0.05). Conclusions Exogenous HMGB1 can promote angiogenesis in ischemic zone of early scald wounds of rats by increasing expressions of VEGF and CD31.
Antiseptic effect of compound lysostaphin disinfectant and its preventive effect on infection of artificial dermis after graft on full-thickness skin defect wound in rats
Jin Jian, Zhou Hao, Cui Zhenci, Wang Li, Luo Pengfei, Ji Shizhao, Hu Xiaoyan, Ma Bing, Wang Guangyi, Zhu Shihui, Xia Zhaofan
2018, 34(4): 225-232. doi: 10.3760/cma.j.issn.1009-2587.2018.04.007
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Objective To study the antiseptic effect of compound lysostaphin disinfectant and its preventive effect on infection of artificial dermis after graft on full-thickness skin defect wound in rats. Methods (1) Each one standard strain of Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were selected. Each 20 clinical strains of Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were collected from those isolated from wound exudates of burn patients hospitalized in our wards from January 2014 to December 2016 according to the random number table. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of compound lysostaphin disinfectant to above-mentioned strains were detected. The experiment was repeated 3 times. Compared with the corresponding standard strain, the clinical strain with higher MIC and/or MBC was considered as having decreased sensitivity to the disinfectant. The percentage of strains of each of the three kinds of bacteria with decreased sensitivity was calculated. (2) Artificial dermis pieces were soaked in compound lysostaphin disinfectant for 5 min, 1 h, 2 h, and 4 h, respectively, with 21 pieces at each time point. After standing for 0 (immediately), 12, 24, 36, 48, 60, 72 h (with 3 pieces at each time point), respectively, the diameters of their inhibition zones to standard strains of Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were measured. The experiment was repeated 3 times. The shortest soaking time corresponding to the longest standing time, after which the disinfectant-soaked artificial dermis could form an effective inhibition zone (with diameter more than 7 mm), was the sufficient soaking time of the disinfectant to the artificial dermis. (3) Forty Sprague-Dawley rats were divided into post injury day (PID) 3, 7, 14, and 21 sampling groups according to the random number table, with 10 rats in each group. A full-thickness skin defect wound with a diameter of 20 mm was made on both sides of the spine on the back of each rat. Immediately after injury, the artificial dermis without any treatment was grafted on the wound on left side of the spine (hereinafter referred to as control wound), while the sufficiently soaked artificial dermis with compound lysostaphin disinfectant was grafted on the wound on right side of the spine (hereinafter referred to as disinfectant wound). On PID 3, 7, 14, and 21, the gross condition of wounds of all the surviving rats was observed, and the new infection rates of control wounds and disinfectant wounds were calculated. Then, the rats in the sampling group with corresponding time were killed, and the full-thickness wound tissue containing artificial dermis was collected for quantitative analysis of bacteria. Bacteria content of the uninfected control wounds and that of the uninfected disinfectant wounds were compared. Data were processed with chi-square test and Wilcoxon rank sum test. Results (1) The MIC of compound lysostaphin disinfectant to standard strains of Staphylococcus aureus, Klebsiella pneumoniae, and Acinetobacter baumannii were 1/32, 1/32, and 1/512 of the original concentration of the disinfectant, respectively, and the MBC were 1/32, 1/16, and 1/512 of the original concentration of the disinfectant, respectively. The percentages of clinical strains of Klebsiella pneumoniae, Acinetobacter baumannii and Staphylococcus aureus with decreased sensitivity to compound lysostaphin disinfectant were 15% (3/20), 20% (4/20), and 10% (2/20), respectively. (2) After being soaked in compound lysostaphin disinfectant for 2 and 4 h, the longest standing time, after which the artificial dermis could form an effective inhibition zone against Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus, were 24, 36, and 48 h respectively, longer than 12, 24, and 24 h of soaking for 5 min and 24, 24, and 36 h of soaking for 1 h. The sufficient soaking time of compound lysostaphin disinfectant to artificial dermis was 2 h. (3) On PID 3, no infection symptom was observed in all the wounds, and so both the new infection rate of control wounds and that of disinfectant wounds were 0. The artificial dermis was transparent but not well connected with the wound. On PID 7, the new infection rate of control wounds was 20.00% (6/30), which was obviously higher than 3.33% (1/30) of disinfectant wounds, χ2=4.043, P<0.05. On the infected wound, a large amount of purulent exudates were observed, and the artificial dermis was not connected with the wound and degraded partially. On the uninfected wound, artificial dermis was transparent and had a partial connection with the wound. On PID 14 and 21, no new infected wound was observed, and so both the new infection rate of control wounds and that of disinfectant wounds were 0. There was no obvious improvement on the infected wounds. The collagen layers of artificial dermis in the uninfected wound established a good connection with the wound and were separating from the silica gel layer gradually. Infection occurred in 2, 3, 1 control wound (s) in PID 7, 14, and 21 sampling groups, respectively, and in 1 disinfectant wound in PID 14 sampling group. The bacteria content of the infected wounds tissue was 0.79×106 to 7.22×109 colony-forming unit (CFU)/g. The bacteria content of uninfected control wounds tissue in PID 3, 7, and 14 sampling groups were (3.43±1.88)×102, (2.37±0.43)×103, and (8.40±1.03)×103 CFU/g, respectively, which were significantly higher than (0.33±0.12)×102, (0.43±0.17)×103, (2.16±0.52)×103 CFU/g of uninfected disinfectant wounds tissue (Z=-3.780, -3.554, -3.334, P<0.05). The bacteria content of uninfected control wounds tissue and that of uninfected disinfectant wounds tissue in PID 21 sampling group were similar (Z=-0.490, P>0.05). Conclusions Compound lysostaphin disinfectant has quite strong antibacterial ability against Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus. Clinical strains of the three kinds of bacteria were highly sensitive to compound lysostaphin disinfectant. Saturation of absorption of compound lysostaphin disinfectant achieves in artificial dermis after 2 hours′ soaking. After 24, 36, and 48 hours′ standing, the soaked artificial dermis still has the antibacterial effect on Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus, respectively. The infection rate and the bacteria content of full-thickness skin defect wound in rats are all decreased when grafted with soaked artificial dermis.
Application of recombinase polymerase amplification in the detection of Pseudomonas aeruginosa
Jin Xiaojun, Gong Yali, Yang Li, Mo Banghui, Peng Yizhi, He Peng, Zhao Junning, Li Xiaolu
2018, 34(4): 233-239. doi: 10.3760/cma.j.issn.1009-2587.2018.04.008
Abstract:
Objective To establish an optimized method of recombinase polymerase amplification (RPA) to rapidly detect Pseudomonas aeruginosa in clinic. Methods (1) The DNA templates of one standard Pseudomonas aeruginosa strain was extracted and detected by polymerase chain reaction (PCR), real-time fluorescence quantitative PCR and RPA. Time of sample loading, time of amplification, and time of detection of the three methods were recorded. (2) One standard Pseudomonas aeruginosa strain was diluted in 7 concentrations of 1×107, 1×106, 1×105, 1×104, 1×103, 1×102, and 1×101 colony forming unit (CFU)/mL after recovery and cultivation. The DNA templates of Pseudomonas aeruginosa and negative control strain Pseudomonas putida were extracted and detected by PCR, real-time fluorescence quantitative PCR, and RPA separately. The sensitivity of the three methods in detecting Pseudomonas aeruginosa was analyzed. (3) The DNA templates of one standard Pseudomonas aeruginosa strain and four negative control strains (Staphylococcus aureus, Acinetobacter baumanii, Candida albicans, and Pseudomonas putida) were extracted separately, and then they were detected by PCR, real-time fluorescence quantitative PCR, and RPA. The specificity of the three methods in detecting Pseudomonas aeruginosa was analyzed. (4) The DNA templates of 28 clinical strains of Pseudomonas aeruginosa preserved in glycerin, 1 clinical strain of which was taken by cotton swab, and negative control strain Pseudomonas putida were extracted separately, and then they were detected by RPA. Positive amplification signals of the clinical strains were observed, and the detection rate was calculated. All experiments were repeated for 3 times. Sensitivity results were analyzed by GraphPad Prism 5.01 statistical software. Results (1) The loading time of RPA, PCR, and real-time fluorescence quantitative PCR for detecting Pseudomonas aeruginosa were all 20 minutes. In PCR, time of amplification was 98 minutes, time of gel detection was 20 minutes, and the total time was 138 minutes. In real-time fluorescence quantitative PCR, amplification and detection could be completed simultaneously, which took 90 minutes, and the total time was 110 minutes. In RPA, amplification and detection could also be completed simultaneously, which took 15 minutes, and the total time was 35 minutes. (2) Pseudomonas putida did not show positive amplification signals or gel positive results in any of the three detection methods. The detection limit of Pseudomonas aeruginosa in real-time fluorescence quantitative PCR and PCR was 1×101 CFU/mL, and that of Pseudomonas aeruginosa in RPA was 1×102 CFU/mL. In RPA and real-time fluorescence quantitative PCR, the higher the concentration of Pseudomonas aeruginosa, the shorter threshold time and smaller the number of cycles, namely shorter time for detecting the positive amplified signal. In real-time fluorescence quantitative PCR, all positive amplification signal could be detected when the concentration of Pseudomonas aeruginosa was 1×101-1×107 CFU/mL. In RPA, the detection rate of positive amplification signal was 0 when the concentration of Pseudomonas aeruginosa was 1×101 CFU/mL, while the detection rate of positive amplification signal was 67% when the concentration of Pseudomonas aeruginosa was 1×102 CFU/mL, and the detection rate of positive amplification signal was 100% when the concentration of Pseudomonas aeruginosa was 1×103-1×107 CFU/mL. (3) In RPA, PCR, and real-time fluorescence quantitative PCR, Pseudomonas aeruginosa showed positive amplification signals and gel positive results, but there were no positive amplification signals or gel positive results in four negative control strains of Acinetobacter baumannii, Staphylococcus aureus, Candida albicans, and Pseudomonas putida. (4) In RPA, 28 clinical strains of Pseudomonas aeruginosa preserved in glycerin and 1 clinical strain of Pseudomonas aeruginosa taken by cotton swab showed positive amplification signals, while Pseudomonas putida did not show positive amplification signal. The detection rate of positive amplification signal of 29 clinical strains of Pseudomonas aeruginosa in RPA was 100%. Conclusions The established optimized RPA technology for fast detection of Pseudomonas aeruginosa requires shorter time, with high sensitivity and specificity. It was of great value in fast detection of Pseudomonas aeruginosa infection in clinic.
Review
Advances in the research of biomechanical effects of negative-pressure wound therapy in promoting wound healing
Chen Xiaoqiang, Zhang Wei, Li Xueyong
2018, 34(4): 243-246. doi: 10.3760/cma.j.issn.1009-2587.2018.04.010
Abstract:
Recently, researchers have focused on the micro-mechano-environment and the resulting mechanical cues which can regulate the morphology, structure, and function of cells. As a novel mechanotherapy, negative-pressure wound therapy (NPWT) has revolutionized the treatment of acute and chronic wounds. The effects of mechanics in use of NPWT has been noticed by researchers, and sporadic results have been reported, while the mechanisms of mechanosensitivity and mechanotransduction in affecting cell behaviors and promoting wound healing haven′t been elucidated yet. In this article, we review the progress about the relevant mechanical forces of NPWT and the mechanical effects on major repairing cells involved in wound healing, in order to provide references for the better understanding of mechanobiology of NPWT to better wound healing.
Advances in the research of application of artificial intelligence in burn field
Li Haihang, Bao Zhenxing, Liu Xiaobin, Zhu Shihui
2018, 34(4): 246-248. doi: 10.3760/cma.j.issn.1009-2587.2018.04.011
Abstract:
Artificial intelligence has been able to automatically learn and judge large-scale data to some extent. Based on database of a large amount of burn data and in-depth learning, artificial intelligence can assist burn surgeons to evaluate burn surface, diagnose burn depth, guide fluid supply during shock stage, and predict prognosis, with high accuracy. With the development of technology, artificial intelligence can provide more accurate information for burn surgeons to make clinical diagnosis and treatment strategies.
Advances in the research of effects of glutamine on immune function of burn patients
Liu Yanhua, Guo Pengfei, Chen Gaiyun, Bo Yacong, Ma Yan, Cui Zhengjun
2018, 34(4): 249-253. doi: 10.3760/cma.j.issn.1009-2587.2018.04.012
Abstract:
Glutamine is the most abundant amino acid found in plasma and cells. It is the preferred fuel for enterocytes in the small intestine, macrophages, and lymphocytes. After serious burn, increased requirement of glutamine by the gastrointestinal tract, kidney and lymphocytes, and relatively insufficient self synthesis likely contribute to the rapid decline of glutamine in circulation and cells. Glutamine supplementation can not only protect intestinal mucosa, maintain normal intestinal barrier function, reduce bacterial translocation, and enhance the intestinal immune function, but also increase the number of lymphocytes, enhance the phagocytic function of macrophage, promote the synthesis of immunoglobulin, and reduce the body′s inflammatory response, so as to enhance the immune function. Therefore, glutamine supplementation can improve and enhance the immune function, reduce complications and promote the prognosis of severely burned patients.
Advances in application of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 system in stem cells research
Sun Sujing, Huo Jiahui, Geng Zhijun, Sun Xiaoyan, Fu Xiaobing
2018, 34(4): 253-256. doi: 10.3760/cma.j.issn.1009-2587.2018.04.013
Abstract:
Gene engineering has attracted worldwide attention because of its ability of precise location of disease mutations in genome. As a new gene editing technology, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) system is simple, fast, and accurate to operate at a specific gene site. It overcomes the long-standing problem of conventional operation. At the same time, stem cells are a good foundation for establishing disease model in vitro. Therefore, it has great significance to combine stem cells with the rapidly developing gene manipulation techniques. In this review, we mainly focus on the mechanism of CRISPR/Cas9 technology and its application in stem cell genomic editing, so as to pave the way for promoting rapid application and development of CRISPR/Cas9 technology.