[Multicenter evaluation of minimal residual disease monitoring in early induction therapy for treatment of childhood acute lymphoblastic leukemia]

Objective: To evaluate the role of minimal residual disease (MRD) monitoring during early induction therapy for the treatment of childhood acute lymphoblastic leukemia (ALL). Methods: This was a multicenter retrospective cohort study. Clinical data of 1 164 ALL patients first diagnosed between October 2016 and June 2019 was collected from 16 hospitals in South China Children's Leukemia Group. According to MRD assay on day 15 of early induction therapy, they were divided into MRD<0.10% group, MRD 0.10%-<10.00% group and MRD≥10.00% group. According to MRD assay on day 33, they were divided into MRD<0.01% group, MRD 0.01%-<1.00% group and MRD≥1.00% group. Age, onset white blood cell count, central nervous system leukemia (CNSL), molecular genetic characteristics and other data were compared between groups. Kaplan-Meier method was used for survival analysis. Cox regression model was used to analyze prognostic factors. Results: Of the 1 164 enrolled patients, there were 692 males and 472 females. The age of diagnosis was 4.7 (0.5, 17.4) years. The white blood cell count at initial diagnosis was 10.7 (0.4, 1 409.0) ×109/L. Among all patients, 53 cases (4.6%) had CNSL. The follow-up time was 47.6 (0.5, 68.8) months. The 5-year overall survival (OS) and 5-year relapse-free survival (RFS) rates were (93.1±0.8) % and (90.3±1.1) %. On day 15 of early induction therapy, there were 466 cases in the MRD<0.10% group, 523 cases in the MRD 0.10%-<10.00% group and 175 cases in the MRD≥10.00% group. The 5-year OS rates of the MRD<0.10% group, MRD 0.10%-<10.00% group and MRD≥10.00% group were (95.4±1.0) %, (93.3±1.1) %, (85.4±2.9) %, respectively, while the RFS rates were (93.2±1.6) %, (90.8±1.4) %, (78.9±4.3) %, respectively (χ2=16.47, 21.06, both P<0.05). On day 33 of early induction therapy, there were 925 cases in the MRD <0.01% group, 164 cases in the MRD 0.01%-<1.00% group and 59 cases in the MRD≥1.00% group. The 5-year RFS rates in the MRD 0.01%-<1.00% group was lowest among three groups ((91.4±1.2) % vs. (84.5±3.2) % vs. (87.9±5.1) %). The difference between three groups is statistically significant (χ2=9.11, P=0.010). Among ALL patients with MRD≥10.00% on day 15 of induction therapy, there were 80 cases in the MRD <0.01% group on day 33, 45 cases in the MRD 0.01%-<1.00% group on day 33 and 45 cases in the MRD≥1.00% group on day 33. The 5-year RFS rates of three groups were (83.9±6.0)%, (67.1±8.2)%, (83.3±6.9)% respectively (χ2=6.90, P=0.032). Univariate analysis was performed in the MRD≥10.00% group on day 15 and the MRD 0.01%-<1.00% group on day 33.The 5-year RFS rate of children with CNSL was significantly lower than that without CNSL in the MRD≥10.00% group on day 15 ((50.0±20.4)% vs. (80.3±4.4)%,χ2=4.13,P=0.042). Patients with CNSL or MLL gene rearrangement in the MRD 0.01%-<1.00% group on day 33 had significant lower 5-year RFS rate compared to those without CNSL or MLL gene rearrangement ((50.0±25.0)% vs. (85.5±3.1)%,χ2=4.06,P=0.044;(58.3±18.6)% vs. (85.7±3.2)%,χ2=9.44,P=0.002). Multivariate analysis showed that age (OR=0.58, 95%CI 0.35-0.97) and white blood cell count at first diagnosis (OR=0.43, 95%CI 0.27-0.70) were independent risk factors for OS. The MRD level on day 15 (OR=0.55,95%CI 0.31-0.97), ETV6-RUNX1 fusion gene (OR=0.13,95%CI 0.03-0.54), MLL gene rearrangement (OR=2.55,95%CI 1.18-5.53) and white blood cell count at initial diagnosis (OR=0.52,95%CI 0.33-0.81) were independent prognostic factors for RFS. Conclusions: The higher the level of MRD in early induction therapy, the worse the OS. The MRD levels on day 15 is an independent prognostic factor for RFS.The MRD in early induction therapy guided accurate risk stratification and individualized treatment can improve the survival rate of pediatric ALL.

[Epidemiological investigation and analysis of etiological characteristics of infection on 3 067 hospitalized pediatric patients with burns]

Objective: To investigate the epidemiological characteristics and etiological distribution of infection on 3 067 hospitalized pediatric patients with burns, and explore the prevention and treatment strategy of pediatric burns. Methods: A cross-sectional survey was conducted. An analysis was performed on the data of 3 067 hospitalized pediatric patients with burns who met the inclusion criteria and were admitted to the First Affiliated Hospital of Army Medical University (the Third Military Medical University) from January 2012 to December 2020, including gender, age, causative factors, locations and severities of burns, seasons of accidents, and the type, source of tissue or body fluid, and drug resistance of pathogenic bacteria. API bacterial identification batten and automatic microbial identification system were applied for pathogen identification. Drug sensitivities of top 3 consistent ratio pathogen identifed were tested with minimum inhibitory concentration and disk diffusion method. WHONET 5.6 software was applied to analyze the data. Results: There were 3 067 hospitalized pediatric patients with burns, including 1 768 boys and 1 299 girls. The majority of pediatric burn patients were >1 and ≤4 years, accounting for 72.9% (2 236/3 067), and the minority of pediatric burn patients were >8 and ≤12 years, accounting for 4.9% (150/3 067). Moderate burns and severe burns of pediatric burn patients accounted for the majority parts, and the proportions of the two were close. The top cause of pediatric burns was scald, accounting for 81.6% (2504/3 067). Extremities were the most common burn sites in that of entire 3 254. The most pediatric burns occurred in winter, accounting for 29.4% (903/3 067). A total of 1 018 strains of pathogenic bacteria were collected from pediatric burn patients, all of which were non-repeated isolates. The pathogens with top five consistent ratio were Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloacae, and Escherichia coli, among which Staphylococcus aureus ranked the first every year. The pathogens were mainly isolated from the wound exudate, accounting for 81.34% (828/1 018). Staphylococcus aureus from 2012 to 2020 showed no resistance to vancomycin, linezolid or teicoplanin while Staphylococcus aureus isolated in 2019 was 100% resistant to macrolides, penicillin, aminoglycosides, and quinolones. Pseudomonas aeruginosa was not resistant to polymyxin B. Acinetobacter baumannii showed a high rate of drug resistance to most antibiotics. Conclusions: Among the pediatric burn patients admitted to the First Affiliated Hospital of Army Medical University (the Third Military Medical University) from 2012 to 2020, the majority are male children aged >1 and ≤4 years with moderate burns. Scalds are the leading cause; and extremities are the common burn sites; and the most pediatric burns occurre in winter. Staphylococcus aureus from wound exudate is the primary pathogen of burn wound infections in pediatric patients.

[The mechanism, prevention and diagnosis of cutaneous adverse drug reaction]

Adverse drug reactions are often encountered in the process of medication and are quite troublesome for clinicians. Skin is one of the most frequently affected organs by adverse drug reactions. Adverse drug reactions involving skin are called "drug-induced dermatitis" or "drug eruption". In some rare instances, drug eruption can be severe and life-threatening which is known as severe cutaneous adverse drug reaction. However, due to the mixed use of drugs, it is difficult to identify the culprit drug, which makes multiple drugs needed to be avoided. Recently, many studies have found that HLA alleles are closely related to the certain culprit drug. HLA genotyping before administration can significantly reduce the incidence of severe cutaneous adverse drug reaction related to certain drugs. Since limited HLA alleles are found, HLA genotyping can only prevent adverse drug reaction to a limited extent. At present, drug provocation tests are regarded as the "gold standard" to identify the culprit drug. However, this diagnostic program has not been widely developed because of the high risk. In addition, a variety of in vivo and in vitro diagnostic methods (including drug patch test, drug skin test, drug specific IgE test, basophil activation test, lymphocyte transformation test, et al) also provide evidences to identify the culprit drug.

[Effect of endoplasmic reticulum stress induced by all-trans retinoic acid on apoptosis of FLT3-ITD mutated leukemia cells by activating autophagy in FLT3-ITD mutated protein]

Objective: Endoplasmic reticulum stress(ERS)was used as the research emphasis to further investigate the mechanisms of apoptosis of FLT3-ITD-mutated leukemia cells and decreased expression of FLT3-ITD mutated protein induced by all-trans retinoic acid(ATRA). Methods: FLT3-ITD-mutated leukemia cell lines(MV4-11 and MOLM13)were treated with ATRA. Flow cytometry was conducted to assess cell apoptosis. Real-time fluorescent quantitative PCR(RT-qPCR)and Western blot were used to detect the expression of ERS-related and autophagy-related genes and protein, respectively. Results: A low-dose ATRA further increased FLT3-ITD cells and ERS levels. ATRA acted on the ERS-related PERK/eif2ɑ signaling pathway and continued to increase the ERS of FLT3-ITD cells, resulting in an upregulation of apoptotic gene CHOP expression. After the treatment with ATRA, FLT3-ITD protein in FLT3-ITD cells was decreased. Of the two main ERS-related protein degradation pathways, ER-associated degradation(ERAD)and ER-activated autophagy(ERAA), the expression of ERAD-related protein ATF6 in FLT3-ITD cells was not significantly changed on ATRA, whereas the expression of ERAA-related proteins Atg7 and Atg5 were significantly increased. Conclusions: ATRA further raises the ERS level of FLT3-ITD cells continuously by activating the ERS-related PERK/eif2ɑ signal pathway and induces FLT3-ITD protein autophagy degradation through ERAA pathway, which induces apoptosis of FLT3-ITD-mutated leukemia cells. These results provide preliminary evidence on the use of ATRA in the treatment of refractory leukemia with FLT3-ITD.

[Analysis of the pathogenic characteristics of fungal bloodstream infection in severe burn patients]

Objective: To retrospectively analyze the diagnosis time, pathogen distribution, and drug resistance of fungal bloodstream infection in severe burn patients. Methods: Blood samples were collected from 55 severe burn patients with fungal bloodstream infection (including 46 males and 9 females, aged 42 (1, 78) years) admitted to the intensive care unit of the Institute of Burn Research of the First Affiliated Hospital of Army Medical University (the Third Military Medical University) from July 2011 to May 2019 for retrospective analysis. Microbial monitoring system was used to cultivate pathogens, API yeast identification kit and Candida chromogenic medium were used to identify pathogens, and Kirby-Bauer paper disk diffusion method was used to detect drug resistance of fungi to fluconazole, amphotericin B, itraconazole, ketoconazole, and voriconazole. The positive rate of blood fungal culture, mortality rate, distribution of local fungal proliferation sites, the diagnosis time distribution of fungal bloodstream infection, the distribution of fungal species, resistance to commonly-used antifungal drugs, and the use of antibiotics were assessed. The WHONET 5.6 software was applied to analyze the distribution and drug resistance of fungi. Results: (1) Totally 4 839 blood samples were collected during the 9 years, and 122 strains of fungi were isolated, with positive rate of 2.52%. The mortality rate was 14.55% (8 patients) in 55 patients. Catheter fungal proliferation ranked the first among 30 cases of local fungal proliferation. (2) The diagnosis time of fungal bloodstream infection mainly distributed in ≤1 week of hospitalization [32.73% (18/55)]. (3) Among the 55 strains of fungi detected, the detection rate of Candida parapsilosis ranked the first (21.82%, 12 strains), Candida glabrata was the second (18.18%, 10 strains), and Candida tropicalis was tied with Candida albicans in the third place (14.55%, 8 strains). All the detected fungi were sensitive to amphotericin B, and the resistance rates to voriconazole, fluconazole, itraconazole, and ketoconazole were between 4.5% and 9.1%. (4) Droad-spectrum antibiotics were used in all the 55 patients, ≥3 kinds of antibiotics were used in 44 patients, and 37 patients used antibacterial drugs ≥7 days. Conclusions: The diagnosis time of fungal bloodstream infection in the 55 severe burn patients was mainly within 1 week of hospitalization. Candida parapsilosis is the most commonly detected fungal species. Catheter fungal proliferation occurs most commonly among the 30 patients with local fungal proliferation. All the detected fungi were sensitive to amphotericin B, with low drug resistance to voriconazole, fluconazole, itraconazole, and ketoconazole. Broad-spectrum antibiotics were overused in the severe burn patients with fungal bloodstream infection.

[Analysis of distribution and drug resistance of pathogens isolated from 159 patients with catheter-related bloodstream infection in burn intensive care unit]

Objective: To analyze the distribution and drug resistance of pathogens isolated from patients with catheter-related bloodstream infection (CRBSI) in burn intensive care unit (BICU). Methods: From January 2011 to December 2018, among 2 264 patients who were peripherally inserted central venous catheter at the BICU of the First Affiliated Hospital of Army Medical University (the third Military Medical University), hereinafter referred to as the author's unit, 159 patients were diagnosed CRBSI, including 131 males and 28 females, aged 43 (1, 79) years. The pathogens primarily isolated from peripheral venous blood and central venous catheter blood/anterior central venous catheter specimen of patients with CRBSI were retrospectively analyzed. API bacteria identification kits and automatic microorganism identification instrument were used to identify pathogens. Broth micro-dilution method or Kirby-Bauer paper disk diffusion method was used to detect the drug resistance of the pathogens to 5 antifungal drugs including fluconazole and itraconazole, etc., and 37 antibacterial drugs including tigecycline and imipenem, 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 WHONET 5.6 software was applied to analyze the annual incidence of CRBSI, mortality of patients with CRBSI, incidence of CRBSI cases, distribution of infection site, and duration of catheterization, detection of Gram-negative and Gram-positive bacteria, fungi, methicillin-resistant Staphylococcus aureus (MRSA), and methicillin-sensitive Staphylococcus aureus (MSSA), and drug resistance of fungi and major Gram-negative and Gram-positive bacteria to the commonly used antibiotics in clinic. Results: (1) The incidence of CRBSI was 7.0% (159/2 264) during the eight years, which was slightly higher in 2014 and 2017 with 13.6% (30/221) and 11.1% (24/217) respectively. The mortality rate of patients with CRBSI was 7.5% (12/159). (2) The incidence of CRBSI cases was 14.9% (338/2 264); the main infection site was femoral vein, totally 271 cases (80.2%), and the duration of catheterization of this site was 9 (2, 25) d. (3) During the eight years, totally 543 strains of pathogens were isolated, including 353 (65.0%) strains of Gram-negative bacteria, 140 (25.8%) strains of Gram-positive bacteria, and 50 (9.2%) strains of fungi. The top three isolated pathogens with isolation rate from high to low were Acinetobacter baumannii, Staphylococcus aureus, and Pseudomonas aeruginosa, accounting for 23.2% (126/543), 17.1% (93/543), and 15.7% (85/543), respectively. Fungi were mainly Candida parapsilosis. Among the Staphylococcus aureus, the detection rate of MRSA was 98.9% (92/93), and that of MSSA was 1.1% (1/93). (4) Except for the low drug resistance rates to polymyxin B, minocycline, and tigecycline, the drug resistance rates of Acinetobacter baumannii to the other antibiotics were considerably high (80.1%-100.0%). Pseudomonas aeruginosa was not resistant to polymyxin B but highly resistant to netilmicin (88.7%) and piperacillin (92.6%), with resistance rates to the other antibiotics from 34.5% to 62.7%. Klebsiella pneumoniae was not resistant to tigecycline and lowly resistant to imipenem and meropenem (28.9%, 9 imipenem- and meropenem-resistant strains were further confirmed by modified Hodge test), with resistance rates to the other antibiotics from 40.9% to 95.2%. The resistance rates of MRSA to most antibiotics were higher than those of MSSA. MRSA was not resistant to linezolid, vancomycin, teicoplanin, sulfamethoxazole, or tigecycline. The resistance rates of MRSA to clindamycin and erythromycin were 7.9% and 62.0%, respectively, and those to the other antibiotics were higher than 91.5%. Except for the complete resistance to penicillin G and tetracycline, MSSA was not resistant to the other antibiotics. Thirty-three strains of Staphylococcus aureus showed resistance to erythromycin-induced clindamycin. Fungi was not resistant to amphotericin B, with drug resistance rates to voriconazole, itraconazole, ketoconazole, and fluconazole from 4.2% to 6.2%. Conclusions: The incidence of CRBSI and mortality of patients with CRBSI are high in BICU of the author's unit, and the main infection site is femoral vein. There are various types of pathogens in patients with CRBSI, and most of them are Gram-negative. The top three isolated pathogens are Acinetobacter baumannii, Staphylococcus aureus, and Pseudomonas aeruginosa, accompanying with grim drug resistance phenomenon.

[Current status of occupational stress among medical staff in Shenzhen, China and related influencing factors]

Objective: To investigate the current status of occupational stress in medical staff in Shenzhen, China, and to provide a reference for developing health administrative policy and reducing occupational stress in medical staff. Methods: From January to June, 2018, a cross-sectional survey was performed in 992 medical workers who were selected from 2 municipal hospitals and 2 district hospitals by stratified random sampling. General information was collected, Occupational Stress Inventory-Revised Edition was used to investigate occupational stress, and univariate and multivariate analyses were performed based on a descriptive analysis of related results. Results: For the medical staff in Shenzhen, the scores of Occupational Role Questionnaire, Personal Stress Questionnaire, and Personal Resources Questionnaire were 185.67±17.55, 108.45±15.56, and 122.74±16.56, respectively. Age, degree of education, type of work, job title, professional title, and permanent or temporary job were influencing factors for occupational task (P<0.05) ; age, working years, type of work, and night shift were influencing factors for personal stress response (P<0.05) ; working years, type of work, professional title, and weekly working hours were influencing factors for personal coping resources (P<0.05) . Conclusion: There is a high degree of occupational stress among medical staff in Shenzhen, and it is recommended to improve medical resources in Shenzhen, reduce occupational stress among medical staff, and increase coping resources.

[Analysis of distribution and drug resistance of pathogens from the wounds of 1 310 thermal burn patients]

Objective: To analyze the distribution and drug resistance of pathogens from the wounds of thermal burn patients, so as to provide reliable basis for the rational use of antibiotics and the effective control over nosocomial infection. Methods: Wound samples of 1 310 thermal burn patients admitted into our burn wards from January 2012 to December 2017 were collected and retrospectively analyzed. API bacteria identification panels and automatical bacteria identification equipment were used to identify pathogens. E test was conducted to detect drug resistance of pathogens to vancomycin, tigecycline, and oxacillin. Kirby-Bauer paper disk diffusion method was used to detect drug resistance of pathogens to 31 antibiotics including penicillin G, gentamicin and rifampicin, etc., and drug resistance of fungi to 5 antifungal agents (voriconazole, amphotericin B, fluconazole, itraconazole, and ketoconazole). The WHONET 5.6 software was used to analyze the constituent ratios of Gram-negative bacteria, Gram-positive bacteria, and fungi in each year; the distribution of fungi; the distribution of top 10 bacteria with the highest constituent ratios in each year; the constituent ratios of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA); the drug resistance of top 3 bacteria with the highest constituent ratios to commonly used antibiotics in each year; and the drug resistance of Candida to commonly used antifungal agents. Results: (1) Totally 2 183 strains of pathogens were isolated for the first time, including Gram-negative bacteria 1 194 (54.70%) strains, Gram-positive bacteria 879 (40.27%) strains, and fungi 110 (5.04%) strains. From 2012 to 2016, the constituent ratio of Gram-negative bacteria showed a decreasing trend, while that of Gram-positive bacteria showed an increasing trend year by year; and the constituent ratio of fungi was with a significantly increasing trend from 2016 to 2017. (2) Among all the fungi, the constituent ratio of Candida parapsilosis ranked the first, Aflatoxin ranked the second, Candida albicans and Candida tropicalis both ranked the third. (3) From 2012 to 2017, top 10 bacteria with the highest constituent ratios, from high to low, were Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloacae, Escherichia coli, Staphylococcus haemolyticus, Klebsiella pneumoniae, Enterococcus faecalis, Aeromonas hydrophila, and Stenotrophomonas maltophilia respectively. The constituent ratio of Staphylococcus aureus ranked the first in each year. The constituent ratio of Pseudomonas aeruginosa was fluctuating but showed a rising trend comprehensively. The constituent ratio of Acinetobacter baumannii went up after decreasing. (4) Among all the Staphylococcus aureus, constituent ratio of MRSA was above 65.00%, while that of MSSA was below 31.00% in each year. (5) From 2012 to 2017, Staphylococcus aureus resistant to vancomycin, linezolid, or teicoplanin was not detected; the drug-resistant rates of MRSA to penicillin G, oxacillin, gentamicin, rifampicin, tetracycline, ciprofloxacin, ofloxacin, and levofloxacin were above or equal to 80.0% in each year; the drug-resistant rates of Staphylococcus aureus to clindamycin and erythrocin showed an obviously increasing trend, the drug-resistant rates of Staphylococcus aureus to moxifloxacin and queenoputin/daputin in 2017 were higher than those in 2016, while the drug-resistant rates of Staphylococcus aureus to the other 14 antibiotics showed no significant change in trend. From 2012 to 2017, Acinetobacter baumannii was sensitive to polymyxin B and tigecycline; the drug-resistant rate of Acinetobacter baumannii to ceftriaxone was relatively high; the drug-resistant rates of Acinetobacter baumannii to levofloxacin, minocycline, and tetracycline were decreasing while those to the other 14 antibiotics went up after decreasing. From 2012 to 2017, Pseudomonas aeruginosa wasn't resistant to polymyxin B, and its drug-resistant rates to the other 14 antibiotics showed decreasing trends. (6) The drug-resistant rates of Candida albicans to voriconazole, amphotericin B, fluconazole, itraconazole, and ketoconazole were all zero. The drug-resistant rates of non-Candida albicans to voriconazole, fluconazole, itraconazole, and ketoconazole were higher than those of Candida albicans. Conclusions: Among the pathogens from the wounds of thermal burn patients, Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii had the top 3 constituent ratios; the constituent ratio of non-Candida albicans was obviously higher than that of Candida albicans. The high drug resistance rates of Staphylococcus aureus and Acinetobacter baumanni require more attention from clinicians and the local hospital's infection control department.

[Effects of exogenous high mobility group protein box 1 on angiogenesis in ischemic zone of early scald wounds of rats]

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.

Closed path integrals and the quantum action

We suggest a closed form expression for the path integral of quantum transition amplitudes. We introduce a quantum action with parameters different from the classical action. We present numerical results for the harmonic oscillator with weak perturbation, the quartic potential, and the double well potential. The quantum action is relevant for quantum chaos and quantum instantons.