Objective To evaluate the differences of α-fetoprotein (AFP), ffeeβ-human chorionic gnnadotropin (HCG) indexes in 3 foreign median databases for antepartum risk screening, and establish the median databases of normal pregnant women in Wenzhou for antepartum screening of AFP, free-β-HCG indexes through the suitable median computational models. Methods The levels of AFP and free β-HCG of 20054 normal pregnant women in Wenzhou were detected by time-resolved fluorometry. The data in this paper were compared with the data of 2T-risk ( 2T), Lifecycle-2. 2 (LC2.2 ) and Lifecycle -3.0 (LC3.0) by double-factor ANOVA. The differences between the data in the paper and the data from Shenyang and Ningbo were analyzed. The median database of Wenzhou pregnant women was established by the suitable regression model, with the stability of nonlinear regression models of the 3 software assessed by model correcting fitting, distribution mean of model fitting logarithmic and standard deviation. Results The levels of AFP and freeβ- hCG reported here were 10% and 16% higher than the data of 2T-risk, 15% and 20% higher than that of LC 2. 2, 6% and 17% higher than that of LC 3.0 respectively. The differences were statistically significant. ( FAFP = 161. 757 ,P < 0. 01 ; Ffree-β-HCG = 58. 261, P < 0.01 ). The levels of AFP and free β- hCG in Wenzhou were 2% higher and 3% lower than that of Shenyang, 1% and 2% higher than that of Ningbo. There was no statistical difference of AFP levels among Wenzhou , Shenyang and Ningbo( FAFP = 0. 174 ,P =0. 840) while the differences of free-β-hCG were statistically significant( F<,free-β-HCG> = 13.303 ,P < 0. 01 ). The differences of quadratic equation regression model, exponent quadratic function regression model and exponent quadru-function regression model of 2T, LC-2. 2 and LC-3.0 were not remarkable. The exponent quadru-function regression model was the best. Conclusions There are significant differences between the data from Wenzhou, Shenyang and Ningbo and the data of T-2 risk, LC-2. 2, LC -3.0. The discrepancy is due to the ethnic and different parameters of regression models. So the model parameters and the median databases are urgently required in China. The differences of large sample size of AFP from Wenzhow, Shengyang and Ningbo are not significant, while the differences of free-β- hCG from Wenzhow, Shengyang and Ningbo is remained because of its instability. The levels from Wenzhow and Ningbo are near. It is suggested that the laboratories with small sample size can establish their own laboratory parameters using the reference obtained from large sample size under the same experimental conditions. There are no significant differences of stability among regression computational models in the 3 software. The exponent quadru-function regression model can be used to establish the median databases for the screening with the similar data distribution in the paper.

Objective: To analyze the epidemiological characteristics of adult inpatients with gas burns in the Department of Burns of Hwa Mei Hospital of University of Chinese Academy of Sciences (hereinafter referred to as the author′s unit) , so as to provide evidence for the prevention of gas burn. Methods: Medical records of all inpatients with flame burns admitted to the author′s unit from January 2011 to December 2017 were collected. The percentage of adult inpatients with gas burns in total inpatients with flame burns in the same period, and their gender, age, injury season, accident place, burn severity, common compound injury, complication, population caliber, education, industry, as well as the pre-injury disease and prognosis of elderly inpatients with gas burns were retrospectively analyzed. In addition, the age, accident place, education, and industry of the floating population in the adult inpatients with gas burns were analyzed separately and compared with the total population of adult inpatients with gas burns in 7 years. Data were processed with chi-square test or Fisher′s exact probability test (Monte Carlo algorithm). Results: During the 7 years, 1 490 inpatients with flame burns were admitted to the author′s unit, among which 511 were adult inpatients with gas burns, accounting for 34.30%. The number of adult inpatients with gas burns increased gradually during the 7 years, but its percentage in the total inpatients with flame burns during the same period showed no significant difference (χ²=7.087, P>0.05). Among the 511 adult inpatients with gas burns (hereinafter referred to as the patients in this group), there were 315 males and 196 females, with a male/female ratio of 1.61 to 1.00, and the middle-aged patients were the most, up to 270 cases, accounting for 52.84%. The distribution of adult inpatients with gas burns during the 7 years was significantly different in gender and age (χ²=54.810, 27.832, P<0.01). Among the patients in this group, most were injured in summer, totally 251 cases, accounting for 49.12%, and the accident place was mainly at home, totally 388 cases, accounting for 75.93%. The distribution of adult inpatients with gas burns during the 7 years was significantly different in injury season (χ²=42.254, P<0.01), but not in accident place (χ²=6.782, P>0.05). The patients in this group were mainly with moderate burns (237 cases, accounting for 46.38%), and the distribution trend of burn severity of adult inpatients with gas burns was basically the same during the 7 years (χ²=19.680, P>0.05); 176 patients (34.44%) were accompanied by inhalation injury, and 30 patients (5.87%) were accompanied by blast injury of lung; post injury complications occurred in 20 patients (3.91%). In the elderly inpatients with gas burns, 44.44% (32/72) were accompanied by pre-injury basic diseases, and the proportion of death or unhealed reached 18.06% (13/72). Most of the patients in this group were permanent residents (358 cases, accounting for 70.06%) and received secondary education (304 cases, accounting for 59.49%), and the majority of them were engaged in manufacturing/construction (138 cases, accounting for 27.01%), self-employed business (90 cases, accounting for 17.61%), and catering (90 cases, accounting for 17.61%) industries. The distribution of adult inpatients with gas burns during the 7 years was significantly different in population caliber, education, and occupation (χ²=17.496, 29.898, 88.896, P<0.05 or P<0.01). Among the patients of this group, the floating population were mainly young (90 cases, accounting for 58.82%) and middle-aged (62 cases, accounting for 40.52%), with main accident place at home (97 cases, accounting for 63.40%), generally received secondary education (101 cases, accounting for 66.01%), and were mainly engaged in manufacturing/construction (71 cases, accounting for 46.41%), self-employed business (26 cases, accounting for 16.99%), and catering (20 cases, accounting for 13.07%) industries. Compared with the total adult inpatients with gas burns in 7 years, the floating population were younger, more injured in the workplace, and more concentrated in industry (χ²=42.924, 9.390, 27.819, P<0.01). Conclusions Gas burn was the leading injury cause of inpatients with flame burns in the author′s unit, which mainly occurred in summer and at home; the patients were mainly male, young and middle-aged, and permanent residents, most of which were with moderate burn, often accompanied by inhalation injury. Most of the patients were of secondary education, engaged in manufacturing/construction, self-employed business, and catering industries, among which the floating population were younger, more injured in the workplace, and more concentrated in industry. In order to prevent gas burn, we should pay more attention to the propaganda and education of gas safety among young and middle-aged men, floating population, retired old people and housewives, especially in summer, we should do a good job in gas safety inspection at home. In addition, we should urge enterprises to further strengthen the supervision of production safety.

Objective:To analyze the dynamic change rule of gut microbiota in patients with extremely severe burns using 16S ribosomal RNA (rRNA) high-throughput sequencing technology.Methods:Five patients with extremely severe burns who were admitted to Hwa Mei Hospital of University of Chinese Academy of Sciences from February to June 2017 and conformed to the inclusion criteria were included in the prospective observational study. All patients were males with age of 32-48 years. Fecal samples were collected in the shock stage (within 3 days after injury), early stage of acute infection (4-14 d after injury), middle stage of acute infection (15-28 d after injury), late stage of acute infection (from 29 d after injury to 1 week before discharge) and within 1 week before discharge. The number of samples was 5 in each stage. The fecal pH value was measured using a pH meter. High-throughput sequencing technology was applied for sequencing of 16S rRNA V3 and V4 regions of fecal samples. QIIME software was used to analyze the number of operational taxonomic units (OTUs), α diversity (Chao1 index and Shannon index), and the relative abundance of gut microbiota at the phylum and family levels. Unweighted pair group method with arithmetic mean clustering method was used to analyze the β diversity of gut microbiota, and Tax4Fun was used to predict functional changes of gut microbiota. Data were statistically analyzed with one-way analysis of variance for repeated measurement, Bonferroni method, Wilcoxon rank sum test for paired samples, and Bonferroni correction.Results:(1) The pH value of feces in the early and middle stages of acute infection in patients with extremely severe burns in this group was 7.40±0.45 and 7.56±0.45 respectively, which were significantly higher than 6.68±0.36 in the shock stage ( P<0.05 or P<0.01). (2) A total of 2 333 584 efficient and high-quality sequences were obtained, and the length of the sequences was about 415 bp. A total of 1 209 OTUs were obtained. The sequencing coverage of all samples was over 99.0%. The number of OTUs and Chao1 index in the early, middle, and late stages of acute infection in patients with extremely severe burns in this group were significantly lower than those in the shock stage ( Z=2.023, P<0.05). The number of OTUs and Chao1 index within 1 week before discharge were significantly higher than those in the early, middle, and late stages of acute infection, and Shannon index within 1 week before discharge was significantly higher than that in the early and middle stages of acute infection ( Z=2.023, P<0.05). (3) The structure of gut microbiota in the shock stage in patients with extremely severe burns in this group was highly similar to that within 1 week before discharge, and lowly similar to that in the early, middle, and late stages of acute infection. The analysis of individual sample showed that the clustering rule of most of the samples was in accordance with that of the staged samples. The weighted Unifrac distance of gut microbiota in the shock stage was significantly shorter than that in the early, middle, and late stages of acute infection ( Z=3.326, 2.570, 2.690, P<0.05 or P<0.01), while the weighted Unifrac distance of gut microbiota in the other stages was similar. (4) At the phylum level, compared with that in the shock stage, the relative abundance of Firmicutes was decreased in the early, middle, and late stages of acute infection, while the relative abundance of Bacteroidetes and Proteobacteria increased. However, the relative abundance of the above three phyla within 1 week before discharge was similar to that in the shock stage. At the family level, the top five dominant bacteria in relative abundance in different stages after injury were quite different. The relative abundance of dominant five family bacteria in the shock stage was decreased in the early, middle, and late stages of acute infection. The relative abundance of non-dominant bacteria such as Enterobacteriaceae, Streptococcaceae, and Bacteroidaceae in the shock stage increased significantly in the early, middle, and late stages of acute infection, which became new dominant families in these stages. The relative abundance of some acid-producing bacteria within 1 week before discharge resumed to the similar level in the shock stage. (5) Functions such as some amino acid metabolism, glycolysis and gluconeogenesis, and pyruvate metabolism of gut microbiota were obviously weaker in the early and middle stages of acute infection than those in the shock stage. Functions such as some amino acid metabolism and carbohydrate metabolism of gut microbiota were significantly enhanced in the late stage of acute infection compared with that in the shock stage. The distributions of functional genes in gut microbiota were similar between the shock stage and within 1 week before discharge. Conclusions:The internal environment and gut microbial compositions in extremely severe burned patients change significantly in the early and middle stages of acute infection. The pH value increases, the bacterial species and diversity decrease, especially the relative abundance of acid-produced bacteria is significantly reduced, which gradually recover with the improvement of the patient′s condition. The pH value and the changes of Proteobacteria and acid-producing bacteria could be considered as suitable parameters for reflecting the disorder level of gut microbiota in patients with extremely severe burns.

Objective:To explore the risk factors of early enteral nutrition intolerance in extremely severe burn patients.Methods:A retrospective case-control study was performed. From January 2018 to December 2020, seventy-six adult patients with extremely severe burns who met the inclusion criteria were admitted to Hwa Mei Hospital of University of Chinese Academy of Sciences, including 55 males and 21 females, aged (45±11) years with burns of 62% (52%, 82%) total body surface area. Depending on the patient's tolerance to early enteral nutrition, they were divided into tolerance group (47 patients) and intolerance group (29 patients), and their clinical data were statistically analyzed, including age, sex, body mass index (BMI), underlying disease, total burn area, full-thickness burn area, abbreviated burn severity index (ABSI) score, implementation of mechanical ventilation on the day of admission, stable shock state, vomiting before feeding. The following data were recorded including the onset time, duration length, and frequency of enteral nutrition intolerance of patients in intolerance group, and the number of operations, the length of hospitalization, the occurrence of sepsis within 2 weeks after injury, the outcome, as well as the serum hypersensitive C-reactive protein (hs-CRP), albumin, fasting blood glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and γ-glutamyl transpeptidase (γ-GT) on post burn day (PBD) 1, 5, 9, and 13 of patients in the two groups. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, and chi-square test to screen the related factors of early enteral nutrition intolerance of the patients. Binary univariate and multivariate logistic regression analysis were used to analyze the independent risk factors of early enteral nutrition intolerance of the patients. Results:There were no statistically significant differences in age, sex, BMI, and percentage of underlying disease of patients between the two groups ( P>0.05). The total burn area, full-thickness burn area, ABSI score, mechanical ventilation percentage on the day of admission, percentage of unstable shock period, percentage of vomiting before feeding of patients in intolerance group were significantly higher than those in tolerance group ( Z=-4.559, -3.378, -4.067, χ 2=18.375, 23.319, 8.339, P<0.01). In intolerance group, the onset time of intolerance was (9±4) d after injury, and the duration length was 4 (2, 6) d, with a total of 46 times occurred. Compared with tolerance group, the percentage of sepsis and mortality of patients in intolerance group were significantly higher within 2 weeks after injury ( χ 2=16.571, 12.665, P<0.01). The number of operation and length of hospitalization of patients in the two groups were similar ( P>0.05); however the length of hospitalization of patients in the intolerance group was significantly more than that in tolerance group after excluding the death cases ( Z=-2.266, P<0.05). On PBD 1, the level of fasting blood glucose and AST of patients in intolerance group were significantly higher than those in tolerance group ( t=3.070, Z=-3.070, P<0.01). On PBD 5, the levels of hs-CRP, albumin, fasting blood-glucose, ALT, AST, and γ-GT of patients in the two groups were similar ( P>0.05). On PBD 9, the level of hs-CRP of patients in intolerance group was significantly higher than that in tolerance group ( t=2.836, P<0.01), and the levels of ALT and γ-GT of patients in intolerance group were significantly lower than those in tolerance group ( Z=-3.932, -2.052, P<0.05 or P<0.01). On PBD 13, the level of hs-CRP of patients in intolerance group was significantly higher than that in tolerance group ( t=3.794, P<0.01), and the levels of fasting blood glucose, ALT, and γ-GT of patients in intolerance group were significantly lower than those in tolerance group ( t=-2.176, Z=-2.945, -2.250, P<0.05 or P<0.01). Binary univariate logistic regression analysis showed that total burn area, full-thickness burn area, ABSI score, implementation of mechanical ventilation on the day of admission, unstable shock period, vomiting before feeding, and fasting blood-glucose on PBD 1 of patients were related to early enteral nutrition intolerance (odds ratio=1.086, 1.052, 1.775, 9.167, 12.797, 10.125, 1.249, 95% confidence interval=1.045-1.129, 1.019-1.085, 1.320-2.387, 3.132-26.829, 4.199-39.000, 2.003-51.172, 1.066-1.464, P<0.01). Multivariate logistic regression analysis showed that the large total burn area, unstable shock period, vomiting before feeding, and high fasting blood-glucose on PBD 1 of patients were the independent risk factors of early enteral nutrition intolerance in patients (odds ratio=1.073, 6.390, 9.004, 1.246, 95% confidence interval=1.021-1.128, 1.527-26.734, 1.134-71.496, 1.007-1.540, P<0.05 or P<0.01). Conclusions:The percentage of early enteral nutrition intolerance is very high in extremely severe burn patients, which is closely related to poor prognosis. Large total burn area, vomiting before feeding, unstable shock phase, high fasting glucose on PBD 1 of patients are the independent risk factors for early enteral nutrition intolerance in extremely severe burn patients. The benefits and risks should be carefully evaluated before starting enteral nutrition in such patients, and early enteral nutrition should not be blindly pursued.