Genetic characterization of a novel blaDIM-2-carrying megaplasmid p12969-DIM from clinical Pseudomonas putida.

OBJECTIVES: To characterize a blaDIM-2-carrying 409 kb megaplasmid p12969-DIM of Pseudomonas putida 12969 from a patient with pneumonia in China. METHODS: The complete nucleotide sequence of p12969-DIM was determined with a paired-end library and a mate-pair library using next-generation sequencing technology. RESULTS: blaDIM-2, a close blaDIM-1 variant, was identified in p12969-DIM. DIM-2 differs from DIM-1 by two amino acid substitutions Ser119Leu and Ser209Pro. The p12969-DIM backbone is highly similar to pOZ176, but the IncP-2-type stability/replication/conjugal transfer system in the pOZ176 backbone is absent from p12969-DIM. The p12969-DIM accessory regions, a 45.7 kb MDR and a novel insertion sequence, ISPpu23, are almost entirely distinct from pOZ176. The MDR region contains a novel Tn21-subgroup transposon Tn6286 inserted with two class 1 integrons, In1225 and In1226; a Tn5503-family transposon-like element inserted with a strAB locus; and a novel Tn21-subgroup transposon-like element inserted with a class 1 integron, In1224. The three integrons carry blaDIM-2 as well as a number of additional genes conferring resistance to quinolones, aminoglycosides, chloramphenicol, florfenicol, trimethoprim, streptomycin, quaternary ammonium compounds and sulphonamides. p12969-DIM has two distinct replication/stability systems, repA/parAB-parB2 of an unknown incompatibility group in the backbone and repABC/mazFE of the IncQ2 group in the MDR region. CONCLUSIONS: The MDR region of p12969-DIM harbours many resistance genes as well as a second replication/stability system. This article is the first report of a fully sequenced blaDIM-carrying plasmid.

Population pharmacokinetics of zonisamide after oral administration in healthy Chinese volunteers.

To develop a population-based pharmacokinetic model for the oral antiepileptic drug zonisamide using a cohort of healthy (nonepileptic) subjects and evaluate the effect of individual factors on the pharmacokinetics of zonisamide. 30 young adults (21-39 years) in good health were randomly assigned to 3 equal groups (1:1 sex ratio) for single-dose administration of zonisamide at 200 mg, 300 mg, or 400 mg. An additional 9 subjects (22-24 years) were administered once daily zonisamide at 300 mg for 14 days, and comprised the multiple dosing group. Venous blood samples were collected for analysis prior to (baseline, 0 hours) and after (1-300 hours) drug administration, providing 607 total samples used to build the pharmacokinetic model. The population pharmacokinetic analysis was performed by ICON's nonlinear mixed-effect modeling (NONMEM) software. Validation of the final model was carried out by nonparametric bootstrapping and visual predictive check. The zonisamide pharmacokinetics was best described by a two-compartment model with first-order elimination. In the final model, the estimated value of clearance (CL) was 23.25 L/h, the volume of distribution of the central compartment (Vc) was 34.50 L, the intercompartmental clearance (Q) was 20.22 L/h, and the Ka was 0.026 h(-1). The peripheral volume of distribution (Vp) was 1,429 L for single dose and 1,003 L for multiple doses. Body weight was the significant covariate affecting CL, Vc, Vp, and Q. Otherwise, female subjects had a lower Q than male subjects. The pharmacokinetics of zonisamide after oral administration could be described using a linear first-order elimination two-compartment model, which may provide a reference for clinical use of zonisamide in Chinese adults.

Antibacterial activity of fosfomycin against uropathogens.

BACKGROUND: In recent years, the rising rates of resistance to antimicrobial drugs among pathogens have caused great difficulty for clinicians treating infectious diseases. The aim of the study was to assess the curative effect of fosfomycin in treating urinary tract infections (UTIs) in China. METHODS: We collected clinical isolates of UTIs to determine their susceptibility to fosfomycin by the agar dilution method and to analyze extended-spectrum ß-lactamase (ESBL)-producing isolates by the double-disc method on Mueller-Hinton agar. Fosfomycin-modifying enzyme analysis was conducted by PCR. Differences between the different groups were determined by the χ(2) test. RESULTS: We collected 433 UTI isolates, and the result showed that the susceptibility rates of clinical isolates were all above 80%. Only Klebsiella pneumoniae was fosA positive, with a positive rate of 26.7%. No correlation was found for the resistance between the antibiotic drugs tested and fosfomycin in the other bacteria, except for cefepime, levofloxacin and ciprofloxacin in Enterobacter cloacae and imipenem in K. pneumoniae. CONCLUSION: Our data suggest that fosfomycin may be a suitable antimicrobial agent for UTI isolates and ESBL-producing bacteria in our hospital.

Activation of the MEK/ERK Pathway Mediates the Inhibitory Effects of Silvestrol on Nasopharyngeal Carcinoma Cells via RAP1A, HK2, and GADD45A.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a malignant tumor associated with Epstein-Barr virus (EBV) infection. Chemoradiotherapy is the mainstream treatment for locally advanced NPC, and chemotherapeutic drugs are an indispensable part of NPC treatment. However, the toxic side-effects of chemotherapy drugs limit their therapeutic value, and new chemotherapy drugs are urgently needed for NPC. Silvestrol, an emerging natural plant anticancer molecule, has shown promising antitumor activity in breast cancer, melanoma, liver cancer, and other tumor types by promoting apoptosis in cancer cells to a greater extent than in normal cells. However, the effects of silvestrol on NPC and its possible molecular mechanisms have yet to be fully explored. METHODS: Cell counting kit-8 (CCK-8), cell scratch, flow cytometry, 5-ethynyl-2'-deoxyuridine (EdU), and Western blot (WB) assays were used to evaluate the effects of silvestrol on the cell viability, cell cycle, apoptosis, and migration of NPC cells. RNA sequencing (RNA-Seq) was used to study the effect of extracellular signal-regulated kinase (ERK) inhibitors on the cell transcriptome, and immunohistochemistry (IHC) to assess protein expression levels in patient specimens. RESULTS: Silvestrol inhibited cell migration and DNA replication of NPC cells, while promoting the expression of cleaved caspase-3, apoptosis, and cell cycle arrest. Furthermore, silvestrol altered the level of ERK phosphorylation. The ERK-targeted inhibitor LY3214996 attenuated silvestrol-mediated inhibition of NPC cell proliferation but not migration. Analysis of RNA-Seq data and WB were used to identify and validate the downstream regulatory targets of silvestrol. Expression of GADD45A, RAP1A, and hexokinase-II (HK2) proteins was inhibited by silvestrol and LY3214996. Finally, IHC revealed that GADD45A, RAP1A, and HK2 protein expression was more abundant in cancer tissues than in non-tumor tissues. CONCLUSIONS: Silvestrol inhibits the proliferation of NPC cells by targeting ERK phosphorylation. However, the inhibition of NPC cell migration by silvestrol was independent of the Raf-MEK-ERK pathway. RAP1A, HK2, and GADD45A may be potential targets for the action of silvestrol.

Characterization of the B-BOX gene family in pepper and the role of CaBBX14 in defense response against Phytophthora capsici infection.

The B-box (BBX) transcription factors are widely implicated in plant growth, development, and response to various biotic and abiotic stresses. However, their roles in the response of pepper to Phytophthora capsici infection (PCI) remain largely unexplored. Here, we report a total of 25 CaBBX genes with an uneven distribution were identified in pepper genome, and their characteristics, phylogenetic relationships, gene structures, conserved domains, and expression profiles were validated. CaBBXs were classified into five major clades (I to V) based on their phylogenetic relationships and conserved domains (presence of one or two B-box domains and a CCT domain). Gene duplication analysis demonstrated that there are two segmental duplication events but no tandem duplication event within pepper genome. Conserved motif and gene structure analysis revealed that the CaBBXs in the same clade have relatively similar motif arrangements and exon-intron patterns. Expression analysis revealed that the CaBBX genes have different expression levels in various tissues, and some of which were significantly induced during PCI and exogenous salicylic acid (SA) treatment. Among them, CaBBX14 displayed remarkable changed expression during PCI and SA treatment. The silencing of CaBBX14 increases pepper susceptibility to PCI, and also decreases in SA content and expression of pathogenesis-related (PR) and SA-related genes compared with control plants. Together, these findings advance our knowledge base on biological functions of CaBBXs in pepper during PCI through the SA signaling pathway, and we provide an example demonstrating that the potential of CaBBX14 to improve pepper resistance to PCI.

Luteolin Inhibits the Biofilm Formation and Cytotoxicity of Methicillin-Resistant Staphylococcus aureus via Decreasing Bacterial Toxin Synthesis.

Owing to the fact that luteolin has antibacterial activity against Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA), its specific mechanism in MRSA is worthy of investigation, which is the focus of this study. Initially, the collected S. aureus strains were treated with luteolin. Then, the minimum inhibitory concentration (MIC) of luteolin against the S. aureus strains was measured by the broth microdilution. The growth curves, biofilm formation, and cytotoxicity of treated S. aureus were detected using a microplate reader. The live and dead bacteria were evaluated using confocal laser scanning microscopy, the bacterial morphology was observed using scanning electron microscopy, and the S. aureus colony-forming unit (CFU) numbers were assessed. The levels of alpha hemolysin (α-hemolysin), delta hemolysin (δ-hemolysin), and hlaA were detected via western blot and RT-PCR. The mortality of mouse model with S. aureus systemic infection was analyzed, and the levels of IL-6, IL-8, IL-10, and TNF-α were quantitated using ELISA. Concretely, the MIC of luteolin against MRSA N315 was 64 µg/mL. Luteolin at 16 µg/mL did not affect the growth of MRSA N315, but inhibited the biofilm formation and CFU, and promoted the morphological changes and death of MRSA N315. Luteolin decreased the cytotoxicity and the levels of α-hemolysin, δ-hemolysin, and hlaA in MRSA N315, elevated MRSA-reduced mice survival rate, and differentially modulated the inflammatory cytokine levels in MRSA-infected mice. Collectively, luteolin inhibits biofilm formation and cytotoxicity of MRSA via blocking the bacterial toxin synthesis.

Successful surgical treatment of polybacterial gas gangrene confirmed by metagenomic next-generation sequencing detection: A case report.

BACKGROUND: We report on a case of Vibrio vulnificus (V. vulnificus) detected by metagenomics next-generation sequencing (mNGS) in a 53-year-old male patient with polymicrobial gas gangrene and successful treatment by surgery. This report raises awareness among dermatologists that when a patient is clinically suspected of a special type of pathogenic infection, the mNGS method should be preferred to identify the patient's pathogen infection as soon as possible and then take effective treatment in time to save patients' lives. CASE SUMMARY: A 53-year-old male who worked in the aquatic market complained of redness and swelling of the lower limbs, blisters and ulcers with fever for 3 d. We used mNGS to test the pathogens in ulcer secretions. The results were returned in 24 h and indicated: V. vulnificus, Fusobacterium necrophorum, Staphylococcus haemolyticus, Staphylococcus aureus, Streptococcus dysgalactiae and Klebsiella aerogenes. This patient was diagnosed with V. vulnificus infection. The emergency operation was performed immediately under combined lumbar and epidural anesthesia: Left leg expansion and exploration (August 10, 2021). After surgery, we continued to use piperacillin sodium tazobactam sodium 4.5 g every 8 h and levofloxacin 0.5 g for anti-infection treatment. The patient underwent further surgery under lumbar anesthesia on August 17, 2021 and August 31, 2021: Left leg deactivation and skin grafting, negative pressure closed drainage and right thigh skin removal. After treatment, the transplanted flap survived. CONCLUSION: We could confirm the diagnosis of Vibrio vulnificus infection within 24 h through mNGS detection and then immediately performed emergency surgery.

[Population pharmacokinetics research of clozapine in Chinese schizophrenic patients].

The goal of this study is to investigate the population pharmacokinetics of oral given clozapine in Chinese schizophrenic patients and to identify possible relationships between population parameters and covariates including demography factors and CYP1A2 genetic polymorphism, so as to create the population pharmacokinetics model to guide individual clinical delivery. Details of drug dosage history, sampling time and concentration of 626 data points from 183 patients were collected retrospectively. The 183 patients were randomly allocated either to the index group (n = 168) or to the validation group (n = 15). Population pharmacokinetic data analysis was performed using the nonlinear mixed-effects model (NONMEM) program on the index group. The values of apparent clearance (CL/F), apparent volume of distribution (V/F) and the constant of absorption rate were estimated. A number of covariates including demographic index, coadministration of other drugs and CYP1A2 genotypes were evaluated statistically for their influence on these parameters. The final population model related clearance with day-dose/BSA (DBSA) and smoke habit (SMOK). Predictive performance of the final model evaluated with the validation group showed insignificant bias between observed and model predicted concentrations. Typical value of CL/F (non-smoking group), V/F and the constant of absorption rate were 28.5 L x h(-1) (5.05%), 1 290 L (16.7%) and 2.26 h(-1) (fixed), inter-patient variability (CV) in CL/F and V/F was) 42.2% and 10.0%, respectively. It was observed that the values of CL/F in the two smoking groups were higher than that in the non-smoking group. The residual variability (SD) between observed and model-predicted concentrations was 45.8 microg x L(-1).

[Efficacy of dermal scaffold for promoting repair of acute full-thickness skin defects in pigs].

OBJECTIVE: To investigate the efficacy of Lando® dermal scaffold for promoting repair of acute full-thickness skin defects in pigs and explore the possible mechanism. METHODS: Three 5 cm×5 cm full-thickness skin defects were created on the left dorsal skin (control group) and another 3 on the right dorsal skin (treatment group) of each of 6 Tibetan pigs. The wounds in the treatment group were covered with a bilayer artificial skin (Lando) and the control wounds with vaseline gauze. In both groups, autogenous split-thickness skin were grafted to the wounds 2 weeks later (with the silicone rubber membrane removed before grafting in the treatment group). At 3 days and 2 and 10 weeks after the injury, the wounds were assessed for general condition and contraction, and tissue samples were collected from the wounds to examine the expressions of α-smooth muscle actin (α-SMA) and transforming growth factor-ß1 (TGF-ß1) using immunohistochemistry and the expressions of MMP-1 and TIMP-1 mRNA using RT-PCR. RESULTS: At 3 days after the injury, the wounds in the 2 groups showed no significant differences in the results of any examinations. At 2 weeks after the injury, the wounds in the treatment group showed rich and more smooth granulation tissues with more regular wound edges compared with the control wounds. At 2 and 10 weeks after the injury, the wound contraction rates in the treatment group were (30.5∓3.4)% and (39.2∓2.8)%, respectively, significantly lower than the rates of (51.8∓2.6)% (t=-29.840, P=0.000) and (60.7∓2.2)% (t=-50.213, P=0.000) in the control group. At 2 weeks, the wound tissues in the treatment group expressed significantly higher levels of α-SMA (t=15.921, P=0.000) and TGF-ß1 (t=29.995, P=0.000) than the control wounds, but at 10 weeks, the expressions of α-SMA (t=-41.823, P=0.000) and TGF-ß1 (t=-99.777, P=0.000) in the treatment group were significantly lower than those in the control group. Compared with those in the control group, the expression of MMP-1 mRNA in the treatment group was significantly lower at 2 weeks (t=-45.412, P=0.000) but significantly higher at 10 weeks (t=78.769, P=0.000), and the expression of TIMP-1 mRNA in the treatment group was significantly lower both at 2 weeks (t=-27.064, P=0.000) and at 10 weeks (t=-40.535, P=0.000). CONCLUSIONS: Lando® dermal scaffold can promote granulation tissue growth possibly in relation with increased TGF-ß1 and decreased MMP-1 expression in the wounds. This scaffold material also reduces wound contraction and lessens scar hyperplasia and contracture after wound healing, probably as a result of decreased α-SMA, TGF-ß1, and TIMP-1 and increased MMP-1 expressions.

Vascularization of Lando® dermal scaffold in an acute full-thickness skin-defect porcine model.

The Lando® dermal scaffold is a newly developed, tissue-engineered dermal scaffold material. This study sought to observe its vascularization in an acute full-thickness skin-defect porcine model. There were eight Tibetan pigs in this research. Six 5 × 5 cm full-thickness skin-defect wounds were prepared on the dorsal area of each pig, which were divided into two groups. The experimental group wounds were covered by Lando® dermal scaffolds, while the other received Vaseline gauzes as blank control. At day 3, 7, 14 and 21 after injury, the general condition of wounds was observed, and wound specimens were obtained for HE staining, Masson staining and the expression of CD31, α-SMA and VEGF, which were examined by immunohistochemistry. The results showed the wounds in the experimental group (Lando) were drier with a lower incidence of infection, and the granulation tissues grew better and smoother than the control group. In the experimental group, the hyperemia, edema and inflammatory reactions were milder, the fibroblasts ingrew earlier, the capillaries grew mostly parallel to the wound surface which resembled normal skin, and the collagen fibers were thicker with more regular arrangement than in the control group. The CD31 + microvessel count, α-SMA + microvessel count and VEGF expression of the experimental group were significantly higher than the control group at day 7 and 14 after injury (p < .05). In conclusion, the Lando® dermal scaffold showed good vascularization at day 14 post grafting in an acute full-thickness skin-defect porcine model, which may be associated with increased expression of VEGF.

Hyperoside inhibits biofilm formation of Pseudomonas aeruginosa.

Pseudomonas aeruginosa (P. aeruginosa) is a common pathogen in hospital-acquired infection and is readily able to form biofilms. Due to its high antibiotic resistance, traditional antibacterial treatments exert a limited effect on P. aeruginosa biofilm infections. It has been indicated that hyperoside inhibits P. aeruginosa PAO1 (PAO1) biofilm formation without affecting growth. Therefore, the current study examined the biofilm formation and quorum sensing (QS) system of PAO1 in the presence of hyperoside. Confocal laser scanning microscopy analysis demonstrated that hyperoside significantly inhibited biofilm formation. It was also observed that hyperoside inhibited twitching motility in addition to adhesion. Data from reverse transcription-quantitative polymerase chain reaction indicated that hyperoside inhibited the expression of lasR, lasI, rhlR and rhlI genes. These results suggest that the QS-inhibiting effect of hyperoside may lead to a reduction in biofilm formation. However, the precise mechanism of hyperoside on P. aeruginosa pathogenicity remains unclear and requires elucidation in additional studies.

Epidemiology and resistance characteristics of Pseudomonas aeruginosa isolates from the respiratory department of a hospital in China.

OBJECTIVES: Pseudomonas aeruginosa is one of the most common pathogens causing nosocomial pneumonia. The aim of this study was to investigate the epidemiology and resistance of P. aeruginosa isolated from hospitalised patients in the respiratory department of a hospital in China. METHODS: Clinical isolates were collected from the respiratory department of Southwest Hospital (Chongqing, China) from January 2013 to December 2014. Patients' social and demographic information was obtained from the hospital's information system. Antimicrobial susceptibility was assessed using the agar dilution method. Screening for carbapenemase production among carbapenem-resistant P. aeruginosa was performed using the modified Hodge test and MBL Etest, and carbapenemase-encoding genes were amplified by PCR. Amplification and sequencing of the oprD gene were performed for carbapenem-resistant P. aeruginosa. Sequence types were determined by multilocus sequence typing (MLST). RESULTS: A total of 92 P. aeruginosa isolates were collected from patients in the respiratory department, and piperacillin/tazobactam was the most effective antibiotic against these isolates. Multivariate analysis revealed that antibiotic use prior to admission was an independent risk factor for P. aeruginosa infection. The isolates comprised 25 genotypes, the most common of which were ST235 and ST111. The blaIMP-4 gene was present in 4 isolates and blaVIM-2 in 1 isolate among the 24 carbapenem-resistant isolates. Most of the carbapenem-resistant isolates contained mutational inactivation of the oprD gene. CONCLUSIONS: These results suggested that patients and the hospital environment were sources of P. aeruginosa in nosocomial infections. Mutational inactivation of the oprD gene might be the main mechanism of carbapenem resistance.

The resistance and transmission mechanism of Acinetobacter baumannii isolates in a tertiary care hospital, China.

The aim of this study was to analyse the resistance and epidemiological data of 117 Acinetobacter baumannii isolates from Southwest Hospital, Chongqing, China. Except for polymyxin B, tigecycline, minocycline, cefoperazone/sulbactam, amikacin and levofloxacin, the resistance rates of other antimicrobial agents were above 90%. All the clinical isolates had the blaOXA-51 gene and 114 isolates had the blaOXA-23 gene. Forty-nine isolates were found to contain the blaIMP-4 gene. PFGE data showed that 117 isolates were divided into 25 groups. Sixty-three (53.85%) were found to carry the class 1 integron, and the sequence analysis of the class 1 integron internal variable regions - five types, one of which had the blaIMP-4 gene. For the blaIMP-4 positive strain without class 1 integron, we found the flanking sequence had the TnpA gene. The result suggested that the resistance gene was widely distributed in our hospital; moreover, the modes of presence and transmission are different and complicated. The results of our study can improve the infection empirical treatment method and infection control programme.

[Anti-inflammatory activity and healing-promoting effects of topical application of emu oil on wound in scalded rats].

OBJECTIVE: To investigate the effects of topical application of emu oil on wound healing in scalded rats. METHODS: In 144 male Wistar rats with 10%; total body surface superficial II degree scald treated on a random basis with physiological saline, povidone iodine and emu oil, respectively, the changes of the wound were observed and the wound tissue and blood samples harvested at different times after injury for evaluation of histopathological changes, total tissue water content (measured by wet:dry weight ratios), and tumor necrosis factor (TNF)-alpha levels in the wound tissue and plasma by enzyme-linked immunosorbent assay (ELISA). The general condition of the wound healing was also observed. RESULTS: After application of emu oil, the swelling and effusion of the burn wound were alleviated and evidences of wound infection or adverse effects were not observed. Pathological examination showed that emu oil could alleviate topical inflammation, which was particularly obvious on days 1 and 3 after injury as compared with the other two groups. On day 3 after injury, water content and TNF-alpha level in the tissues was markedly decreased with the application of emu oil (P<0.05), with a significant correlation between their changes (P<0.001) and shortened wound healing time (P<0.05). Pathological examination showed that emu oil could promote epithelialization and differentiation of various epidermal layers. CONCLUSION: Emu oil has topical anti-inflammatory activity in rats with superficial II degree scald, possibly in association with decreased levels of the proinflammatory cytokines in the tissues and can promote wound healing by inhibiting local secondary inflammation.

[Management of extensive burn accompanying severe inhalation injury].

OBJECTIVE: To review our clinical experiences in the treatment of extensive burn accompanied by severe inhalation injury. METHODS: A retrospective analysis was conducted of 18 such cases admitted from 2000 to 2003 in light of the curative rate, mortality rate and measures for effective management. RESULTS AND CONCLUSIONS: Fifteen patients (83.3%) were cured and 3 (16.7%) died. The curative rate of extensive burn accompanied by severe inhalation injury can be enhanced by combining various treatments, including early preventive tracheostomy, appropriate tracheobronchial lavage, humidification and application of ambroxol; protective lung ventilation, and administration of growth hormones should be done as early as possible.

[Clinical observation on repairing of wounds of skin graft donor site with acellular tissue engineering dermal matrix].

OBJECTIVE: To evaluate the clinical efficacy of acellular tissue engineering dermal matrix (ATDM) in repairing wounds of skin graft donor site. METHODS: Sixty patients with burn or chronic wounds hospitalized from January 2011 to April 2012 received autologous skin grafting. One wound [with size larger than 55 cm(2), and thickness of (0.33 ± 0.03) mm] out of multiple skin graft donor sites of every patient was selected, and it was divided into two parts in accordance with self-control principle. A part of wound close to the wound edge with diameter of 5 cm was taken as trial area (treated with ATDM), and the remaining wound was taken as control area (treated with vaseline gauze) according to the random number table. Blood and urine routine, liver and kidney function, and levels of IgG and IgM in blood of patients were measured one day before operation and on the 1st day after wound healing. Vital signs of patients were recorded on the operation day and the wound healing day. Gross condition of the wounds was observed during dressing change. Wound healing time was recorded. The healed wound was observed histologically. Data were processed with Log rank test or t test. RESULTS: Leucocyte count was lowered on the 1st day after wound healing [(7.1 ± 1.2)×10(9)/L] as compared with that one day before operation [(10.1 ± 1.5)×10(9)/L, t = -12.10, P < 0.01]. The differences were not statistically significant in red blood cell count, haemoglobin level, platelet count, urine routine, levels of indexes of liver and kidney function, levels of IgG and IgM in blood between one day before operation and the 1st day after wound healing, or in vital signs (including body temperature, pulse, respiration, systolic pressure, and diastolic pressure) between the operation day and the wound healing day (with t values from -1.43 to 1.88, P values all above 0.05). No adverse effects such as abnormal exudation, itching, redness and swelling, and exanthema were observed in the wound. The median wound healing time in trial area was 12 d (95% confidence interval: 11 - 13 d), which was significantly shorter than that in control area [17 d (95% confidence interval: 16 - 18 d), χ(2) = 24.9, P < 0.01]. The healed wound of trial area was closer to the normal skin than that of control area in the shape and distribution of Fb and vascular endothelial cell, and the shape of the basilar membrane and the epidermal layer. CONCLUSIONS: ATDM can accelerate healing of wound of skin graft donor site, and no adverse reactions were observed.

[A retrospective analysis of fluid resuscitation in 94 patients with extensive burns].

OBJECTIVE: To analyze the clinical data of adult patients with total burn surface area (TBSA) greater than 50% in Guangzhou and explore the optimal fluid resuscitation protocols for these patients. METHODS: The clinical data of 94 adult patients with a TBSA over 50% treated in our center during 1991-2010 were reviewed. and the former decade. Fluid resuscitation volume of various components in shock stage, urine volume, occurrence of visceral complications and mortality rate within 10 days after injury were compared between patients treated in 1991-1999 and those in 2000-2010. RESULTS: The first 24-h crystalline colloidal fluid ratio, first 24-h infusion volume and the second 24-h crystalloid fluid coefficients were significantly greater in the patients treated in 2000-2010 than in those treated in 1991-1999. The visceral complications and mortality rate were significantly lower in the latter than in the former patients (7.69% vs 27.3% and 2.56% vs 18.18%, respectively, P<0.05). CONCLUSION: For patients with extensive burns, an individualized fluid resuscitation regimen, an adequately high colloid/crystal rehydration ratio, and a greater total infusion volume according to the local climate of Guangzhou can be beneficial to reduce the incidence of visceral complications and the mortality rate.

[Sequential management of residual wounds in burn patients].

OBJECTIVE: To seek a sequential method for the management of residual wounds in burn patients. METHODS: Three chronic residual wounds on each of 25 burn patients were either covered with vaseline gauze (A group), human tissue-engineered active skin (Active Skin, B group) or Active Skin after rinsing with fluid containing oxygen and vacuum assisted drainage ( C group) on wounds. The contents of (TNF)a in granulation tissue were assayed by enzyme linked immunosorbent assay (ELISA). Expression of metalloproteinase-13 (MMP-13) mRNA in granulation tissue was determined with reverse transcription polymerase chain reaction (RT-PCR). Moreover, quantity of wound bacteria in the wounds and wound healing rate were determined with usual method. RESULTS: The quantities of wound bacteria in C group on 3,6,9, 12 post-treatment day( PTD) were (5.30 +/- 1.60), (1.30 +/-0.80) , (1.70 +/- 0. 60)and (0.60 +/-0. 10)clone formation unit/ml( CFU/ml) , respectively, which were obviously lower than those in A and B groups. The contents of TNFa and expression of metalloproteinase-13 (MMP-13) mRNA in granulation tissue in C group on 6 PTD were [ (0. 650 +/- 0. 040) ng/mg and 0. 210 +/- 0. 010,] ,respectively, and they were evidently lower than those in A group [(1.550 +/-0. 370)ng/mg,1. 040 +/- 0. 050, P <0.01] and B group (0. 810 +/- 0.080) ng/mg, 0.640 +/- 0.030, P <0.01]. Meanwhile, the contents of (TNF)a and expression of MMP-13 mRNA in B group were also obviously lower than those in A group. The wound healing ratio in C group on 15 and 30 PTD were markedly higher than those in A or B group ( P <0.01). CONCLUSION: Covering the residual burn wounds with Active Skin after rinsing with fluid containing oxygen followed by vacuum assisted drainage can improve repairing of residual burn wounds.