[Multicenter retrospect analysis of early clinical features and analysis of risk factors on prognosis of elderly patients with severe burns]

Objective: To investigate the early clinical characteristics of elderly patients with severe burns and the risk factors on prognosis. Methods: This study was a retrospective case series study. Clinical data of 124 elderly patients with severe burns who met the inclusion criteria and were admitted to the 12 hospitals from January 2015 to December 2020 were collected, including 4 patients from the Fourth People's Hospital of Dalian, 5 patients from Fujian Medical University Union Hospital, 22 patients from Guangzhou Red Cross Hospital of Jinan University, 5 patients from Heilongjiang Provincial Hospital, 27 patients from the First Affiliated Hospital of Naval Medical University, 9 patients from the First Affiliated Hospital of Nanchang University, 10 patients from Affiliated Hospital of Nantong University, 9 patients from Tongren Hospital of Wuhan University & Wuhan Third Hospital, 12 patients from the 924th Hospital of PLA, 6 patients from Zhangjiagang First People's Hospital, 4 patients from Taizhou Hospital of Zhejiang Province, and 11 patients from Zhengzhou First People's Hospital. The patients' overall clinical characteristics, such as gender, age, body mass index, total burn area, full-thickness burn area, inhalation injury, causative factors, whether combined with underlying medical diseases, and admission time after injury were recorded. According to the survival outcome within 28 days after injury, the patients were divided into survival group (89 cases) and death group (35 cases). The following data of patients were compared between the two groups, including the basic data and injuries (the same as the overall clinical characteristics ahead); the coagulation indexes within the first 24 hours of injury such as prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time, D-dimer, fibrinogen degradation product (FDP), international normalized ratio (INR), and fibrinogen; the blood routine indexes within the first 24 hours of injury such as white blood cell count, platelet count, neutrophil-to-lymphocyte ratio, monocyte count, red blood cell count, hemoglobin, and hematocrit; the organ function indexes within the first 24 hours of injury such as direct bilirubin, total bilirubin, urea, serum creatinine, aspartate aminotransferase, alanine aminotransferase, total protein, albumin, globulin, blood glucose, triglyceride, total cholesterol, alkaline phosphatase, creatine kinase, electrolyte indexes (potassium, sodium, chlorine, calcium, magnesium, and phosphorus in blood), uric acid, myoglobin, and brain natriuretic peptide; the infection and blood gas indexes within the first 24 hours of injury such as procalcitonin, C-reactive protein, pH value, oxygenation index, base excess, and lactate; treatment such as whether conducted with mechanical ventilation, whether conducted with continuous renal replacement therapy, whether conducted with anticoagulation therapy, whether applied with vasoactive drugs, and fluid resuscitation. The analysis was conducted to screen the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns. Results: Among 124 patients, there were 82 males and 42 females, aged 60-97 years, with body mass index of 23.44 (21.09, 25.95) kg/m2, total burn area of 54.00% (42.00%, 75.00%) total body surface area (TBSA), and full-thickness burn area of 25.00% (10.00%, 40.00%) TBSA. The patients were mainly combined with moderate to severe inhalation injury and caused by flame burns. There were 43 cases with underlying medical diseases. The majority of patients were admitted to the hospital within 8 hours after injury. There were statistically significant differences between patients in the 2 groups in terms of age, total burn area, full-thickness burn area, and inhalation injury, and PT, APTT, D-dimer, FDP, INR, white blood cell count, platelet count, urea, serum creatinine, blood glucose, blood sodium, uric acid, myoglobin, and urine volume within the first 24 hours of injury (with Z values of 2.37, 5.49, 5.26, 5.97, 2.18, 1.95, 2.68, 2.68, 2.51, 2.82, 2.14, 3.40, 5.31, 3.41, 2.35, 3.81, 2.16, and -3.82, respectively, P<0.05); there were statistically significant differences between two groups of patients in whether conducted with mechanical ventilation and whether applied with vasoactive drugs (with χ2 values of 9.44 and 28.50, respectively, P<0.05). Age, total burn area, full-thickness burn area, serum creatinine within the first 24 hours of injury, and APTT within the first 24 hours of injury were the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns (with odds ratios of 1.17, 1.10, 1.10, 1.09, and 1.27, 95% confidence intervals of 1.03-1.40, 1.04-1.21, 1.05-1.19, 1.05-1.17, and 1.07-1.69, respectively, P<0.05). Conclusions: The elderly patients with severe burns had the injuries mainly from flame burns, often accompanied by moderate to severe inhalation injury and enhanced inflammatory response, elevated blood glucose levels, activated fibrinolysis, and impaired organ function in the early stage, which are associated with their prognosis. Age, total burn area, full-thickness burn area, and serum creatinine and APTT within the first 24 hours of injury are the independent risk factors for death within 28 days after injury in this population.

[Timing and surgery option of keratinized mucosa augmentation around implant site]

In recent years, clinicians have paid more attention to the biological and esthetic effects of the 2 mm keratinized mucosa width (KMW) around dental implant. How to increase the keratinized mucosa is the focus of clinicians. While the free gingival graft (FGG) is still the gold standard of keratinized mucosa augmentation, alveolar ridge preservation (ARP), connective tissue graft (CTG) and apically positioned flap (APF) can also be used to obtain more than 2 mm keratinized mucosa width when they are used before implantation, with implantation, within the implant-healing phase, with second stage of implantation or after rehabilitation according to different indications. This article comprehensively summarizes the influencing factors of timing and surgical procedures for keratinized mucosa augmentation, providing guidance for clinicians to treat peri-implant keratinized mucosa deficiencies.

[Orodental phenotype and genotype findings in 8 Chinese children with hypophosphatasia]

Objective: To analyze the oral phenotype and gene variation of children with hypophosphatasia (HPP), and explore the genotype-phenotype correlations. Methods: Eight children diagnosed with HPP from January 2008 to January 2023 in Children's Hospital,Zhejiang University School of Medicine were recruited in this study. The pathogenic genes of 5 of them were sequentially analyzed and all of their oral manifestations, laboratory tests and genetic variation types were retrospectively analyzed. Results: A total of 8 children were recruited in the study, 3 males and 5 females, aged from 20 months to 104 months, whose main complaints were premature deciduous tooth loss. Among them, 3 children were diagnosed with odonto HPP, and the other 5 children were diagnosed with childhood HPP, including 2 children was odonto HPP at the first diagnosis and modified as childhood HPP at the age of 5. The age range of first deciduous tooth loss is 9 to 18 months, and the age range of diagnosis is 20 to 104 months. The patients of odonto HPP only showed premature loss of deciduous anterior tooth, while the patients with childhood HPP also showed premature loss of multiple deciduous molars. Panoramic radiographic film revealed enlarged pulp chambers and radicular canals in some primary and permanent teeth. The enamel hypoplasia, hypoplastic short roots, and alveolar resorption of deciduous molar were observed in some cases. The serum alkaline phosphatase (ALP) (30-107 U/L) levels of all the patients were lower than that in the normal children of same age and gender, and the ALP value of the 1-3 years old girls with childhood HPP (30-33 U/L) was lower than that of the three children with odonto HPP (61-107 U/L), but there was no significant difference in statistical analysis. There were 8 variation sites of ALP liver/bone/kidney (ALPL) gene detected in 5 children and their families, all of which were missense variation, including the new variants in the mutations of c.1334C>G(p.Ser445Cys) and c.1259G>T(p.Gly420Val) that were not reported in the literature. One case was autosomal dominant inheritance and other 4 cases were complex heterozygous variation with autosomal recessive inheritance. Conclusions: Pediatric stomatologists are often the first doctors to detect childhood and odonto HPP. Diagnosis of mild HPP is often delayed. The severity of HPP is related to serum ALP level and ALPL gene mutation sites.

[Research progress on prevention and treatment of deep vein thrombosis in burn patients]

Deep vein thrombosis (DVT) and pulmonary embolism are common and serious complications in hospitalized patients. DVT may be induced by factors including the vein wall injury, hypercoagulability, and slow blood flow during the pathophysiological changes and treatment process of burn patients, especially severe burn patients. It is of great significance to understand the occurrence of DVT in burn patients, identify the high risk group of DVT formation in burn patients with effective evaluation methods, and carry out safe and effective prevention and treatment. This article briefly reviews research progress on the monitoring, prevention, and treatment of DVT in burn patients.

[Impact of COVID-19 on primary percutaneous coronary intervention in patients with acute ST segment elevation myocardial infarction in Beijing]

Objective: To investigate the impact of COVID-19 on treatment of patients with acute ST segment elevation myocardial infarction(STEMI) undergoing primary percutaneous coronary intervention(PPCI). Methods: This was a multicenter retrospective study. STEMI patients undergoing PPCI from January 1, 2019 to December 31, 2021 were selected, based on the data of Xinnaolvsetongdao App. Clinical data and treatment time indicators, including symptom to first medical contact (S-FMC), symptom to door (StoD), first medical contact to ECG (FMC-ECG), first medical contact to guide wire (FMC-W), door to balloon (DtoB) and total ischemic time in 2019, 2020 and 2021 were compared. STEMI patients aged<60 years were sub-grouped as the young and middle-aged group, and STEMI patients aged≥60 years were sub-grouped as the elderly group. Results: A total of 7 435 (3 305 in 2019, 1 796 in 2020 and 2 334 in 2021) STEMI patients aged (59.6±12.6) years undergoing PPCI were included in this analysis. There were 5 990 males. For STEMI patients with PPCI in 2019, 2020 and 2021, FMC-ECG was 3 (1, 5) min, 3(1, 7) min and 4 (1, 7) min. FMC-W was 73 (56, 87) min, 78 (62, 95) min and 77 (62, 87) min. DtoB was 73 (56, 85) min, 78 (62, 95) min and 77 (62, 86) min. Total ischemic time was 189 (130, 273) min, 196 (138, 295) min and 209 (143, 276) min. FMC-ECG, FMC-W, DtoB and total ischemic time were longer in 2020 and 2021 than in 2019 (all P<0.05). The proportions of patients with FMC-ECG≤10 min (88.4% (1 588/1 796) vs. 92.7% (3 064/3 305), P<0.05), FMC-W≤120 min (87.9% (1 579/1796) vs. 91.7% (3 030/3 305), P<0.05) and DtoB≤90 min (72.3% (1 298/1 796) vs. 80.8% (2 672/3 305), P<0.05) were lower in 2020 than in 2019, whereas no differences were observed in the proportions of patients with FMC-ECG≤10 min (91.3% (2 131/2 334) vs. 92.7% (3 064/3 305), P=0.054), FMC-W≤120 min (92.0% (2 148/2 334) vs. 91.7% (3 030/3 305), P=0.635) and DtoB≤90 min (80.0% (1 867/2 334) vs. 80.8% (2 672/3 305), P=0.424) in 2021 compared with 2019. In the subgroup analysis, the proportions of patients with FMC-ECG≤10 min, FMC-W≤120 min and DtoB≤90 min were lower in the elderly group than in young and middle-aged group in 2019 (all P<0.05). The proportions of patients with FMC-W≤120 min and DtoB≤90 min were lower in the elderly group than in young and middle-aged group in 2021(all P<0.05). No differences were observed in the proportions of patients with FMC-ECG≤10 min, FMC-W≤120 min and DtoB≤90 min between the two group in 2020 (all P>0.05). Conclusions: Affected by the COVID-19, there is a reduction in the number of PPCI cases and treatment delays in STEMI patients, especially in the elderly. After adjusting the treatment strategy and widely applying the Xinnaolvsetongdao APP, the above indicators are significantly improved in 2021 as compared with 2020.

[Clinical efficacy of femoral neck screw system combined with supported hollow screw in treatment of femoral neck fractures with posterometral comminution in young and middle-aged patients]

Objective: To investigate the clinical efficacy of dynamic cross screw system (FNS) for femoral neck fractures in young and middle-aged patients with posterior medial comminution. Methods: A retrospective cohort study. Clinical data of 197 young and middle-aged patients with femoral neck fractures accompanied by posterior medial comminution treated with closed reduction FNS and internal fixation with anti-rotation cannulated screws in Beijing Luhe Hospital, Beijing Jishuitan Hospital and Beijing Tongren Hospital from October 2019 to October 2021 were analyzed retrospectively. According to different surgical methods, the patients were divided into two groups. There were 102 patients in the FNS group, included 55 males and 47 females with a mean age of (40.49±19.79) years; and there were 95 patients in the FNS plus anti-rotation hollow screw group (combined group), included 51 males and 44 females with an average age of (40.03±18.82) years. All patients were followed-up for at least 1 year after surgery. The general clinical data, surgical conditions and Harris score of the hip joint at the last follow-up of the two groups were compared. And the clinical efficacy of the two surgical schemes were evaluated and compared. After surgery, routine X-ray and CT examinations were performed to evaluate the fracture reduction and internal fixation, and the shortening of the femoral neck on the affected side was compared to that of healthy side according to the Zlowodzki method. Results: At the last follow-up, the incidence of fracture reduction loss, screw resection and coxa vara in the combined group were all significantly lower than those in the FNS group [10 (10.5%) vs 28 (27.4%), 1 (1.0%) vs 7 (6.8%) and 9 (9.4%) vs 21 (20.5%), respectively, all P<0.05]. The incidence of nonunion and necrosis of the femoral head in the combined group were both lower than those in the FNS group, but there was no significant difference between two groups (both P>0.05). The postoperative mild, moderate and severe femoral neck shortening in the combined group were all lower than those in the FNS group, and the difference were not statistically significant (all P>0.05). At the last follow-up, the Harris score in the combined group was 84.60±2.08, and it was higher than that in the FNS group (79.57±4.31), but the difference was not statistically significant (P=0.403). Conclusion: FNS plus supporting hollow screw has a good clinical effect on femoral neck fractures in young and middle-aged adults with posterior medial comminution.

[Pay attention to persistent inflammation-immunosuppression-catabolism syndrome in the late stage of severe burns]

With the deepening of researches on organ complications after severe burns and the continuous improvement of monitoring and support technology for organ function, severe burn patients have avoided death in the early and middle to late stages due to shock, infection, etc., and entered the late stage of burns. Due to the failure of timely and effective burn wound healing and long-term exposure and infection of extensive burn wounds, some of these patients were in chronic and critical conditions such as fever, emaciation, and delayed wound healing that are accompanied by decreased immune function, anemia, and hypoproteinemia, etc. It manifested as persistent inflammation-immunosuppression-catabolism syndrome (PICS), leading to prolonged hospitalization and increased long-term mortality. Based on clinical practice of the author's team in burn treatment, this paper briefly expounds the main causes, clinical characteristics, and prevention methods of PICS in the late stage of severe burns of patients, hoping to attract the attention of peers to PICS in the late stage of severe burns.

Brain Activation Evoked by Motor Imagery in Pediatric Patients with Complete Spinal Cord Injury

BACKGROUND AND PURPOSE

Currently, there is no effective treatment for pediatric patients with complete spinal cord injury. Motor imagery has been proposed as an alternative to physical training for patients who are unable to move voluntarily. Our aim was to reveal the potential mechanism of motor imagery in the rehabilitation of pediatric complete spinal cord injury.

MATERIALS AND METHODS

Twenty-six pediatric patients with complete spinal cord injury and 26 age- and sex-matched healthy children as healthy controls were recruited. All participants underwent the motor imagery task-related fMRI scans, and additional motor execution scans were performed only on healthy controls. First, we compared the brain-activation patterns between motor imagery and motor execution in healthy controls. Then, we compared the brain activation of motor imagery between the 2 groups and compared the brain activation of motor imagery in pediatric patients with complete spinal cord injury and that of motor execution in healthy controls.

RESULTS

In healthy controls, compared with motor execution, motor imagery showed increased activation in the left inferior parietal lobule and decreased activation in the left supplementary motor area, paracentral lobule, middle cingulate cortex, and right insula. In addition, our results revealed that the 2 groups both activated the bilateral supplementary motor area, middle cingulate cortex and left inferior parietal lobule, and supramarginal gyrus during motor imagery. Compared with healthy controls, higher activation in the bilateral paracentral lobule, supplementary motor area, putamen, and cerebellar lobules III-V was detected in pediatric complete spinal cord injury during motor imagery, and the activation of these regions was even higher than that of healthy controls during motor execution.

CONCLUSIONS

Our study demonstrated that part of the motor imagery network was functionally preserved in pediatric complete spinal cord injury and could be activated through motor imagery. In addition, higher-level activation in sensorimotor-related regions was also found in pediatric complete spinal cord injury during motor imagery. Our findings may provide a theoretic basis for the application of motor imagery training in pediatric complete spinal cord injury.

[Analysis of the risk factors of persistent inflammation-immunosuppression-catabolism syndrome in patients with extensive burns]

Objective: To investigate the risk factors and treatment outcome of persistent inflammation-immunosuppression-catabolism syndrome (PICS) in patients with extensive burns. Methods: A retrospective case series study was conducted. From January 2017 to December 2021, 220 patients with extensive burns who were admitted to Guangzhou Red Cross Hospital of Jinan University met the inclusion criteria, including 168 males and 52 females, aged 18-84 (43±14) years. According to the occurrence of PICS, the patients were divided into PICS group (84 patients) and non-PICS group (136 patients). The general data such as sex, age, complication of underlying diseases and acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score on admission, sepsis-related organ failure evaluation (SOFA) scores on admission and 14 days post admission, and proportion of patients with mechanical ventilation over 48 h during treatment, special conditions such as total burn area, full-thickness burn area, proportion of patients admitted within 48 h post injury, and exposed deep wound area at the 30th day post injury, outcome indicators such as hospitalization day, total cost of hospital stay, number of surgeries, and death of patients in the 2 groups were collected and analyzed. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, and chi-square test. The multivariate logistic regression analysis was performed on the indicators with statistically significant differences between the two groups except for outcome indicators, and the independent risk factors influencing secondary PICS in patients with extensive burns were screened. Results: The APACHE Ⅱ and SOFA scores on admission, and proportion of patients with mechanical ventilation over 48 h during treatment of patients in PICS group were significantly higher than those in non-PICS group (t=6.78, Z=-4.75, χ2=4.74, respectively, P<0.05). There were no statistically significant differences in the rest of general data of patients between the two groups (P>0.05). The total burn area, full-thickness burn area, and exposed deep wound area at the 30th day post injury in PICS group were significantly greater than those in non-PICS group (t=6.29, Z=-7.25, Z=-8.73, P<0.05), the exposed deep wound areas at the 30th day post injury in PICS group and non-PICS group were respectively 25% (15%, 35%) total body surface area (TBSA) and 8% (0, 13%) TBSA, while the proportion of patients admitted within 48 h post injury was significantly lower than that in non-PICS group (χ2=6.13, P<0.05). The hospitalization day, total cost of hospital stay, and number of surgeries of patients in PICS group were significantly higher than those in non-PICS group (with Z values of -7.12, -8.48, and -6.87, respectively, P<0.05), while the deaths of patients in the 2 groups were similar (P>0.05). The APACHE Ⅱ score on admission and exposed deep wound area at the 30th day post injury both were the independent risk factors for PICS in patients with extensive burns (with odds ratios of 1.15 and 1.07, 95% confidence intervals of 1.06-1.25 and 1.05-1.10, respectively, P<0.05). Conclusions: The APACHE Ⅱ score on admission and exposed deep wound area at the 30th day post injury are the independent risk factors for PICS in patients with extensive burns. The patients with secondary PICS had good prognosis with more surgical intervention and hospitalization day, and higher total cost of hospital stay.

[Clinical evaluation of antral septal maxillary sinus floor elevation by the disk-up sinus reamer]

Objective: To investigate the clinical effect of disk-up sinus reamer (DSR) in maxillary sinus floor elevation with maxillary sinus septum. Methods: Twenty-four patients were included between January 2019 to January 2020 in Department of Oral Implantology, The Affiliated Hospital of Qingdao University. There were 10 males and 14 females with the age of (39.3±11.7) years old (range 22-56 years). Pre-operative(T0) cone-beam CT (CBCT) was taken for measurement and analysis. All patients were divided into group E (easy situations, septum located anterior to the zygo-matic process), group M (moderate situations, septum located pos-terior to the zygo-matic process) and group D (difficult situations, sagittally oriented septum). The maxillary sinus floor was grafted through the crestal approach by DSR and implants were placed simultaneously. Permanent repair was performed 6-8 months after operation. All patients underwent CBCT before surgery, after surgery immediately (T1), 6 months after surgery(T2), 1 year after surgery(T3), 2 year after surgery(T4). The residual bone height (RBH) and the vertical bone height (VBH) were analyzed. The mucosal perforation rate, implant survival rate were counted. Results: All the 24 patients completed the Maxillary sinus lift surgery successfully and 24 implants were placed simultaneously. All patients had no headache, dizziness. The mucosal perforation rate was 0. The survival rate of implants during the healing period was 100%(24/24). The RBH was (5.81±2.56) mm pre-operation, the VBHT1, VBHT2, VBHT3 and VBHT4 were (11.82±1.09), (10.98±0.52), (10.66±0.44) and (10.40±0.33) mm, respectively. The differences between the groups by pairing test were statistically significant (F=187.70, P0.001), expect VBHT3 and VBHT4 (P=0.071). Bone resorption and remodeling mainly occurred 1 year after surgery. One patient developed peri-implantitis 18 months after surgery. Conclusions: With the RBH of implant site>2 mm and existence of maxillary sinus septum, using DSR for sinus floor elevation has a high success rate. It can obtain enough bone height and complete the simultaneous implantation to form a good osseointegration. The DSR is simple, safe and controllable, and can shorten the operation time.

Isolation, identification, and evaluation of the biocontrol potential of a Bacillus velezensis strain against tobacco root rot caused by Fusarium oxysporum

AIMS

Tobacco (Nicotiana tabacum) is an economically important crop. Root rot caused by Fusarium oxysporum has become a damaging disease in N. tabacum crops grown in Henan province of China. Therefore, the objectives of this study were to screen bacterial isolates against F. oxysporum from rhizosphere soils of tobacco growing areas and to evaluate their antifungal activities, biocontrol effects, and effects on plant growth.

METHODS AND RESULTS

Nineteen strains with antifungal inhibition effects of >60% against F. oxysporum were obtained using the method of flat confrontation; the strain Ba-0321 was the strongest, with an antifungal effect of 75%. Moreover, this strain had broad spectrum antimicrobial activity to eight additional tobacco pathogens. The strain was identified as Bacillus velezensis by morphology and the 16S rDNA sequence. The B. velezensis strain Ba-0321 had strong UV resistance as well as tolerance to high temperatures and low nutrition. The bacteria inhibited spore germination and mycelial growth of F. oxysporum under in vitro co-culture conditions. In vivo assays demonstrated that the Ba-0321 strain significantly reduced the pathogenicity of F. oxysporum, resulting in a control effect on tobacco root rot of 81.00%. Simultaneously, the bacteria significantly promoted root development and the growth of tobacco plants.

CONCLUSION

Our results confirmed that the B. velezensis strain Ba-0321 has a strong antifungal effect and stress resistance that enable it to be used as a biological control agent for tobacco root rot caused by F. oxysporum.

SIGNIFICANCE AND IMPACT OF THE STUDY

Tobacco root rot caused by F. oxysporum has become a damaging disease in China. The B. velezensis strain Ba-0321 has promising application value for controlling tobacco root rot diseases, and it could provide a new biocontrol agent against root rot caused by F. oxysporum in other plant species.

[Analysis of the clinical characteristics and risk factors of postoperative atrial fibrillation in patients with critical burns]

Objective: To investigate the clinical characteristics and risk factors of postoperative atrial fibrillation (POAF) in patients with critical burns. Methods: A retrospective case series study was conducted. From January 2017 to December 2021, two hundred and twenty-seven critically burned aldult patients who met the inclusion criteria were admitted to Guangzhou Red Cross Hospital of Jinan University, including 173 males and 54 females, aged 19-83 (43±14) years. The admission years of patients were collected, and the percentage of patients complicated with POAF in each year was calculated. According to whether the patients were complicated with POAF or not, they were divided into POAF group (n=17) and non-POAF group (n=210). Following data were collected in patients in POAF group, including operation methods, duration of operation, intraoperative blood loss before occurrence of POAF each time, occurrence time and times of POAF, postoperative body temperature, blood pressure, hemoglobin, blood glucose, blood lactate, sepsis, and electrolyte, and type, duration, and treatment of POAF. General data of patients in the two groups including age, gender, burn reason, total burn area, full-thickness burn area, acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) and sepsis-related organ failure evaluation (SOFA) scores on admission, combined with underlying diseases (hypertension, diabetes, and other types of arrhythmias), and sepsis were collected and analyzed. The mortality and factors influencing the prognosis of patients in the two groups such as mechanical ventilation time, operations times, and burn intensive care unit (BICU) length of stay were also collected and analyzed. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, chi-square test or Kruskal-Wallis H test. The multivariate logistic regression analysis was performed on the general data with statistically significant differences between the two groups, and the independent risk factors influencing the onset of POAF in 227 patients with critical burns were screened. Results: From 2017 to 2021, the percentage of critically burned patients complicated with POAF increased year by year. In POAF group, eschar debridement in limbs was the main surgical procedure prior to POAF complication, with the operation time of (3.5±1.2) h and the intraoperative blood loss volume of (365±148) mL.The POAF occurred 25 times in total in patients of POAF group, mostly within one week after the injury and within 6 hours after the operation with most of these patients having POAF only once. When POAF happened, the patients were often complicated with hypothermia, anemia, hyperglycemia, high blood lactate, sepsis, and electrolyte disturbance, and few patients had complications of hypotension. The POAF lasted (5±3) h, with all being paroxysmal atrial fibrillation, and most of POAF patients were reverted to sinus rhythm after amiodarone intervention. Most patients in the two groups suffered from flame burn, and the gender, age, and SOFA score on admission of patients in the two groups were similar (P>0.05); the APACHEⅡ score on admission, total burn area, full-thickness burn area, incidence proportion of sepsis, combined with diabetes and hypertension and other types of arrhythmias of patients in POAF group were significantly higher or larger than those in non-POAF group (t=3.47, with χ2 values of 7.44, 10.86, 12.63, 14.65, 6.49, and 7.52, respectively, P<0.05 or P<0.01). The full-thickness burn area, combined with other types of arrhythmias, and sepsis were the independent risk factors for POAF in 227 critically burned patients (with odds ratios of 4.45, 0.04, and 3.06, respectively, with 95% confidence intervals of 2.23-8.87, 0.01-0.22, and 1.77-5.30, respectively, P<0.01). Compared with those in non-POAF group, the mechanical ventilation time, BICU length of stay, number of operations, and mortality rate of patients in POAF group were significantly increased (Z=3.89, Z=2.57, t=3.41, χ2=3.72, P<0.05 or P<0.01). Conclusions: POAF is a common postoperative complication in critically burned patients, and the incidence is increasing year by year, which seriously affects the prognosis of patients. The full-thickness burn area together with other types of arrhythmias and sepsis are the high-risk factors for POAF complication in patients with critical burns.

[Myocardial biopsy of Liwen procedure: representability and etiological diagnostic value of cardiac samples obtained by a novel technique in patients with hypertrophic cardiomyopathy]

Objective: To investigate the representability and etiological diagnostic value of myocardium samples obtained from patients with hypertrophic cardiomyopathy (HCM) by transthoracic echocardiography-guided percutaneous intramyocardial septal biopsy (myocardial biopsy of Liwen procedure). Methods: This study was a retrospective case-series analysis. Patients with HCM, who underwent myocardial biopsy of Liwen procedure and radiofrequency ablation in Xijing Hospital, Air Force Military Medical University from July to December 2019, were included. Demographic data (age, sex), echocardiographic data and complications were collected through electronic medical record system. The histological and echocardiographic features, pathological characteristics of the biopsied myocardium of the patients were analyzed. Results: A total of 21 patients (aged (51.2±14.5) years and 13 males (61.9%)) were enrolled. The thickness of ventricular septum was (23.3±4.5)mm and the left ventricular outflow tract gradient was (78.8±42.6)mmHg (1 mmHg=0.133 kPa). Eight patients (38.1%) were complicated with hypertension, 1 patient (4.8%) had diabetes, and 2 patients (9.5%) had atrial fibrillation. Hematoxylin-eosin staining of myocardial samples of HCM patients before radiofrequency ablation evidenced myocytes hypertrophy, myocytes disarray, nuclear hyperchromatism, hypertrophy, atypia, coronary microvessel abnormalities, adipocyte infiltration, inflammatory cell infiltration, cytoplasmic vacuoles, lipofuscin deposition. Interstitial fibrosis and replacement fibrosis were detected in Masson stained biopsy samples. Hematoxylin-eosin staining of myocardial samples of HCM patients after radiofrequency ablation showed significantly reduced myocytes, cracked nuclear in myocytes, coagulative necrosis, border disappearance and nuclear fragmentation. Quantitative analysis of myocardial specimens of HCM patients before radiofrequency ablation showed that there were 9 cases (42.9%) with mild myocardial hypertrophy and 12 cases (57.1%) with severe myocardial hypertrophy. Mild, moderate and severe fibrosis were 5 (23.8%), 9 (42.9%) and 7 (33.3%), respectively. Six cases (28.6%) had myocytes disarray. There were 11 cases (52.4%) of coronary microvessel abnormalities, 4 cases (19.0%) of adipocyte infiltration, 2 cases (9.5%) of inflammatory cell infiltration,6 cases (28.5%) of cytoplasmic vacuole, 16 cases (76.2%) of lipofuscin deposition. The diameter of cardiac myocytes was (25.2±2.8)μm, and the percentage of collagen fiber area was 5.2%(3.0%, 14.6%). One patient had severe replacement fibrosis in the myocardium, with a fibrotic area of 67.0%. The rest of the patients had interstitial fibrosis. The myocardial specimens of 13 patients were examined by transmission electron microscopy. All showed increased myofibrils, and 9 cases had disorder of myofibrils. All patients had irregular shape of myocardial nucleus, partial depression, mild mitochondrial swelling, fracture and reduction of mitochondrial crest, and local aggregation of myofibrillary interfascicles. One patient had hypertrophy of cardiomyocytes, but the arrangement of muscle fibers was roughly normal. There were vacuoles in the cytoplasm, and Periodic acid-Schiff staining was positive. Transmission electron microscopy showed large range of glycogen deposition in the cytoplasm, with occasional double membrane surround, which was highly indicative of glycogen storage disease. No deposition of glycolipid substance in lysozyme was observed under transmission electron microscope in all myocardial specimens, which could basically eliminate Fabry disease. No apple green substance was found under polarized light after Congo red staining, which could basically exclude cardiac amyloidosis. Conclusion: Myocardium biopsied samples obtained by Liwen procedure of HCM patients are representative and helpful for the etiological diagnosis of HCM.

[Hashimoto's encephalopathy presenting with isolated cerebellar ataxia in 13 children]

Objective: To analyze the clinical characteristics, treatment and prognosis of Hashimoto's encephalopathy presenting with isolated cerebellar ataxia in children. Methods: A retrospective analysis was performed on the clinical features, laboratory tests, neuroelectrophysiological examination, imaging, treatment and outcomes of 13 patients with Hashimoto's encephalopathy presenting with isolated cerebellar ataxia, who were admitted to the Department of Pediatric Neurology of Guangzhou Women and Children's Medical Center from January 2016 to May 2021. Results: Among the 13 cases, 6 were males and 7 were females. The onset age was 2.6 (2.0,3.3) years, 9 children had precursor infection or vaccination before the first course of disease. All the 13 children had gait abnormalities or unsteady sitting, 10 had intentional tremor, 6 had dysarthria, 3 had body tremor, 2 had nystagmus, 3 had fatigue, 3 had hypotonia, 2 had vomiting and 1 had irritability. Thyroglobulin antibody (TgAb) was 500.0 (298.9,587.2) kU/L and thyroid peroxidase antibody (TPOAb) was 621.9 (449.6,869.4) kU/L in 13 cases. Autoantibodies were positive in 9 cases, and cerebrospinal fluid leukocytosis was seen in 4 cases. Regarding electroencephalography result, 4 cases had background slowing and 1 case had occasional sharp waves. Among the 3 patients who had relapses, 1 had cerebellar atrophy shown on cranial magnetic resonance imaging (MRI) during the recurrence. All the patients received intravenous immunoglobulin (IVIG) and intensive methylprednisolone therapy during the first onset, followed by the disappearance of the symptoms, 1 patient had repeated episodes which was decreased after immunosuppressive treatment with Rituximab.Followed up for 25.0 (22.5,33.3) months after the last episode, 12 achieved complete remission and 1 had a wide base gait. Conclusions: Trunk ataxia is the common symptom of Hashimoto's encephalopathy presenting with isolated cerebellar ataxia in children.Children with cerebellar ataxia should be tested for TgAb and TPOAb to detect Hashimoto's encephalopathy, avoiding missed diagnosis and treatment delays; IVIG and intensive steroid therapy is effective, and immunosuppressive therapy for patients with multiple relapses could reduce the recurrence.

Detection of blaKPC and blaNDM genes by duplex PCR with lateral flow dipsticks from sterile body fluid samples

Duplex polymerase chain reaction with lateral flow dipsticks (duplex PCR-LFD) was developed for the simultaneous detection of beta-lactamase Klebsiella pneumoniae carbapenemase (bla_KPC ) and beta-lactamase New Dehli metallo-beta-lactamase (bla_NDM ) genes in body fluid samples. This method was validated using well-characterized isolates. The assessment of the specificity of duplex PCR-LFD showed that there was no cross-reactivity with other targets. The detection limit of the duplex PCR-LFD assay was 20 CFU per ml for bla_KPC and bla_NDM . Among 177 sterile body fluid samples tested by the duplex PCR-LFD assay, 40 were bla_KPC -positive and five were bla_NDM -positive. The results obtained from 122 corresponding Gram-negative bacteria which were isolated from these clinical samples and tested by duplex PCR-LFD assay showed that there were 37 strains carrying bla_KPC genes in 40 bla_KPC -positive samples and three strains carrying bla_NDM genes in five bla_NDM -positive samples. Statistical analysis indicated that there was no significant difference between the direct detection of bla_KPC and bla_NDM genes in clinical sterile body fluid samples and their corresponding clinical isolates. Therefore, duplex PCR-LFD can be effective for the simultaneous detection of bla_KPC and bla_NDM in clinical isolates and directly from clinical samples, which may be helpful for the administration of appropriate antimicrobial treatment.

[Investigation of occupational hazard of 750 kV extra high voltage substations]

Objective: To understand the current status of major occupational hazards in 750 kV extra high voltage (EHV) substations. Methods: In July 2019, through investigating and detecting the sulfur hexafluoride, power frequency electric field and noise occupational hazards of 750 kV EHV substations in substation 1, substation 2, substation 3, substation 4, substation 5, substation 6 and substation 7, the exposure intensity of the sulfur hexafluoride, power frequency electric field and noise intensity that the operators are exposed to during the inspection process were analyzed. Results: The qualified rate of 358 sulfur hexafluoride test results was 100.0% of the seven 750 kV EHV substations. The qualified rate of 8 h time-weighted average of the power frequency electric field of those 750 kV EHV substations contacted by operators was 100.0%. Among the 847 power frequency electric field detection points, the exceeding standard rate of power frequency electric field was 64.3%, and the differences in the power frequency electric field detection exceeding standard rates of different substations and inspection areas were statistically significant (χ²=87.52, 50.86, P<0.01) . The highest exceeding standard rate of power frequency electric field was the circuit breaker inspection area (94.4%, 34/36) . The noise intensity test results of the seven EHV substations were 41.1-79.7 dB (A) , and the qualified rate was 100.0%. Conclusion: The sulfur hexafluoride, power frequency electric field and noise that the operators contacted in 750 kV EHV substations meet the requirements of occupational exposure limits. The inspection areas of main transformers, capacitors, reactors, bus bars and switches have high power frequency electric field radiation, should be select equipment iand give priority to robot inspection, and reasonably adjust the inspection time to reduce the intensity level of substation operators' exposure to power frequency electric field.

[Hesitancy of parents towards vaccines in national immunization program in three regions in China: a cross-sectional study]

Objective: To investigate the incidence and determinants of vaccine hesitancy towards national immunization program in China and understand the current status of parents' hesitancy to different vaccines used in national immunization program. Methods: A cross-sectional survey was conducted in Beijing, Sichuan and Gansu. The methods of proportional probability sampling and convenience sampling were used to select the eligible study subjects for questionnaire surveys. Results: A total of 3 592 parents were enrolled in the study, in whom 38.22% fully accepted all the vaccines, 59.35% agreed to let their children to receive all the vaccines but showed slight concern, and 2.42% had hesitancy to the vaccines. The vaccine with the most hesitancy was polio vaccine (0.89%), followed by diphtheria pertussis tetanus vaccine (0.70%) and hepatitis A vaccine (0.64%). The dominant reason for vaccine hesitancy was the risk-benefit perception of vaccination (31.03%), followed by the low awareness of the parents (21.84%) and the inconvenience caused by distance and time (21.84%). Conclusions: The incidence of vaccine hesitancy towards national immunization program was low in parents in China, but over 50% of the parents showed concern to the vaccines. It is essential to improve the service quality of national immunization program and strengthen the health education about the vaccination to reduce the incidence of vaccine hesitancy in parents.

[Determination of hydrazine in workplace air by gas chromatography with large bore capillary column]

Objective: To determine hydrazine quantitatively in workplace air by gas chromatography with large bore capillary column. Methods: In October 2019, hydrazine in the air was adsorbed by acid silica gel tube sampling and desorped using sulfuric acid solution. After derivatization with furfural and extraction, the content of hydrazine was determined by DM-FFAP capillary column gas chromatography with flame ionization detector. Results: The linear regression equation was y=353.8x+21.2 (r=0.9998) between 0.1-2.0 μg/ml of target concentration. The detection limit was 0.030 μg/ml. The lower limit of quantification was 0.100 μg/ml. If 15 L air sample was collected, the minimum detection concentration was 0.004 mg/m(3) and the minimum quantitative concentration was 0.013 mg/m(3) respectively. The average desorption efficiency was 86.5%-89.4%. The recovery was 94.4%-97.1%. The relative standard deviation was 1.6%-4.9%. Hydrazine and furfural derivative was 2-furaldehyde hydrazine. Conclusion: The method has symmetrical peak shape of hydrazine derivatives chromatographic peaks, short analysis time, easy operation, and is suitable for the determination of the concentration of hydrazine in the air in the workplace.

[Application of pulse contour cardiac output monitoring technology in fluid resuscitation of severe burn patients in shock period]

Objective: To investigate the application of pulse contour cardiac output (PiCCO) monitoring technology in fluid resuscitation of severe burn patients in shock period. Methods: From January 2015 to December 2019, 33 patients with severe burns who were hospitalized in Guangzhou Red Cross Hospital, meeting the inclusion criteria, were recruited into a retrospective cohort study with their clinical information collected. The patients were divided into PiCCO monitoring group with 15 cases (13 males and 2 females, aged (43±13) years) and routine monitoring group with 18 cases (14 males and 4 females, aged (39±9) years) according to the monitoring method used. After admission, all the patients were rehydrated following the rehydration formula of the Third Military Medical University for shock period. In routine monitoring group, the fluid resuscitation of patients was performed by monitoring indicators such as urine volume and blood pressure, while PiCCO monitoring was performed among patients in PiCCO monitoring group, and their fluid resuscitation was guided by the patient's condition and the hemodynamic parameters (without pursuing normal levels of the parameters) of PiCCO monitoring on the basis of normal monitoring indicators in routine monitoring group. The colloids coefficients, the electrolyte coefficients (compared with the corresponding rehydration formula value of 0.75 mL·kg(-1)·% total body surface area (TBSA)(-1) of the Third Military Medical University for shock period during the first 24 h post injury), the total rehydration coefficients, and the urine volumes during the first and second 24 h post injury, the lactic acid level, the base excess level, and the oxygenation index at admission and 24, 48 h after admission, and the mechanical ventilation time, the wound healing time, and the death ratio of patients in the two groups were recorded. The cardiac index, the global end-diastolic volume index (GEDVI), the intrathoracic blood volume index (ITBVI), the extravascular lung water index (EVLWI), and the systemic vascular resistance index (SVRI) of patients in PiCCO monitoring group at post injury hour 24, 48, and 72 and the abnormal cases were recorded. Data were statistically analyzed with Fisher's exact probability test, independent-sample or one-sample t test, analysis of variance for repeated measurement, and Bonferroni correction. Results: During the first 24 h post injury, the colloids coefficients of patients in PiCCO monitoring group was (0.69±0.15) mL·kg(-1)·%TBSA(-1), which was significantly less than (0.85±0.16) mL·kg(-1)·%TBSA(-1) in routine monitoring group (t=-2.612, P<0.05). Compared with the rehydration formula value of the Third Military Medical University for shock period, only the colloids coefficient of patients in routine monitoring group during the first 24 h post injury was significantly increased (t=2.847, P<0.05). There were no statistically significant differences between the two groups in the colloids coefficients of patients during the second 24 h post injury, or the electrolyte coefficients, the total rehydration coefficients, the urine volumes of patients during the first and the second 24 h post injury (t=0.579, -0.011, 0.417, -1.321, -0.137, 0.031, 1.348, P>0.05). The lactic acid level, the base excess level, the oxygenation index of patients at admission and 48 h after admission, and the oxygenation index of patients at 24 h after admission between the two groups were similar (t=-1.837, 0.620, 0.292, -1.792, 1.912, -0.167, 1.695, P>0.05). The levels of lactic acid and base excess of patients in PiCCO monitoring group were (4.8±1.4) and (1.2±5.5)mmol/L, respectively, which were significantly better than (7.0±1.5) and (-2.8±3.0) mmol/L in routine monitoring group at 24 h after admission (t=-3.904, 2.562, P<0.05 or P<0.01). There were no statistically significant differences between the two groups in the mechanical ventilation time or the wound healing time of patients (t=-0.699, -0.697, P>0.05), or the death ratio of patients (P>0.05). In PiCCO monitoring group, the GEDVI, and the ITBVI of patients were lower than the normal low values at post injury hour 24 and 48, which were in the normal range at post injury hour 72; the cardiac index of patients increased gradually and recovered to normal at post injury hour 48; the SVRI of patients increased significantly at post injury hour 24 and then gradually decreased to normal; the EVLWI average of patients at all time points post injury were less than 10 mL/kg. At post injury hour 24, most of the hemodynamic parameters of more than or equal to 8/15 patients in PiCCO monitoring group were abnormal, and the abnormal proportion decreased later. Conclusions: On the basis of traditional monitoring indicators, the use of PiCCO monitoring technology combined with the patient's condition (without pursuing normal levels of the parameters) in guiding the fluid resuscitation in severe burn patients can reduce the usage of colloid and better improve tissue perfusion, with the resuscitation effect being better than conventional monitoring.

Synthesis and characterization of an anti-caries and remineralizing fluorine-containing cationic polymer PHMB-F

Dental caries have become a major global public health problem. Plaque control and remineralization of initial enamel lesions are paramount for the prevention and control of caries. Polyhexamethylene biguanide (PHMB) is a type of cationic amphipathic antibacterial agent with broad-spectrum antibacterial properties and good biological safety. Fluoride delays demineralization and promotes the remineralization of hard dental tissues. However, a high concentration is needed for it to function as an antibacterial agent. In order to create a PHMB with the benefits associated with fluoride, we synthesized a fluorine-containing cationic polymer, PHMB-F. Fourier transform-infrared spectroscopy and solid state nuclear magnetic resonance characterization confirmed the successful synthesis of PHMB-F. Antibacterial tests showed that PHMB-F had better antiseptic efficacy for Streptococcus mutans compared with just PHMB. Moreover, positively-charged PHMB-F allows fluoride ions to exist closer to the enamel surface with negative potential, which markedly lowers the ion concentrations in the microenvironment adjacent to hard dental tissues needed to maintain equilibrium. Thus, only low concentrations of PHMB-F are required for enamel remineralization.

[Short-term outcomes of single incision plus one port laparoscopic surgery for colorectal cancer]

Objective: Although single port laparoscopic surgery has achieved good clinical results, many surgeons are discouraged by the difficulties of operation, conflict of instruments, lack of antagonistic traction, and straight-line perspective. Therefore, some surgeons have proposed a single incision plus one hole laparoscopic surgery (SILS+1) surgical method. This study explored the safety and feasibility of SILS+1 for radical resection of colorectal cancer. Methods: A descriptive cohort study was carried out. The clinical data, including the operation, pathology and recovery situation, of 178 patients with colorectal cancer undergoing SILS+1 at Department of General Surgery, Nanfang Hospital, Southern Medical University from March 2018 to January 2019 were prospectively collected and retrospectively analyzed. Clavien-Dindo criteria was used for postoperative complication evaluation and visual analog scale was used for pain standard. Follow-up studies were conducted through outpatient service or telephone and the follow-up period was up to May 2019. Results: A total of 178 patients with colorectal cancer underwent SILS+1, including 111 male patients (62.4%) with an average age of 59 years. Eleven (6.2%) patients received added 1-3 operation ports during operation, and 1 patient was converted to open surgery due to ileocolic artery hemorrhage. The operative time was (135.2±42.3) minutes. The intraoperative blood loss was (34.6±35.5) ml. The number of harvested lymph nodes was 33.1±17.6. The distal margin was (4.7±17.8) cm. The proximal margin was (10.2±5.3) cm. Operation-related complications were observed in 16 patients (9.0%) within 30 days after the operation, of whom 6 had Clavien-Dindo III complications (3.4%). The postoperative pain scores were lower than 3. The average postoperative hospital stay was (5.6±2.6) days. Three patients (1.7%) returned to hospital within 30 days after operation due to intestinal obstruction and infection around stoma. The cosmetic evaluation of all the patients was basically satisfied. Conclusion: SILS+1 is safe and feasible in the treatment of colorectal cancer, and can reduce the postoperative pain.

Burden of colorectal cancer attributable to diet low in milk in China, 1990-2017: findings from the global burden of disease study 2017

BACKGROUND

Colorectal cancer (CRC) has emerged as a major public health concern. However, little is known about the burden attributable to specific risk factors. The present study aimed to estimate the temporal trends and geographical variation of CRC burden attributable to a diet low in milk in China.

METHODS

Following the general analytic strategy used in the 2017 Global Burden of Disease study, we assessed the age-, sex-, and province-specific mortality and disability-adjusted life-years (DALYs) of CRC caused by a diet low in milk in China from 1990 to 2017.

RESULTS

In 2017, a diet low in milk contributed 32 032 [95% uncertainty interval (UI) = 11 350-53 806] deaths and 726 710 (95% UI = 256 651-1 218 153) DALYs for CRC with a population attributable fraction of 17.1%. The age-standardised mortality and DALY rates per 100 000 were 1.7 (95% UI = 0.6-2.9) and 36.8 (95% UI = 13.0-61.7), respectively. An upward trend with age in rates of mortality and DALYs was observed. Males had higher age-standardised rates than females. The number of deaths and DALYs increased significantly from 1990 to 2017, whereas the corresponding age-standardised rates showed relatively stable trends. In 2017, Hunan and Liaoning were ranked as the top two provinces in terms of disease burden. Socio-demographic index had a weak correlation with the age-standardised mortality (r = 0.348, P = 0.047).

CONCLUSIONS

The present study shows a substantial increase in the CRC burden attributable to a diet low in milk over the past three decades. Greater priority in CRC prevention should be given to males and the elderly population throughout China, particularly in less-developed provinces.

[Evaluation of drug-drug interactions between yimitasvir phosphate capsules with sofosbuvir tablets, omeprazole magnesium enteric-coated tablets, and rosuvastatin calcium tablets]

Objective: To evaluate the drug-drug interactions and the tolerability of combined medication between yimitasvir phosphate capsules with sofosbuvir tablets, omeprazole magnesium enteric-coated tablets, and rosuvastatin calcium tablets in healthy volunteers. Methods: A randomized, open, and continuous administration design was used in trial 1 (yimitasvir phosphate capsules with sofosbuvir tablets). 28 subjects were randomly divided into two groups. A non-randomized, open design was used in trial 2 (yimitasvir phosphate capsules with omeprazole magnesium enteric-coated tablets), and included 42 subjects divided into three groups. The open design method was used in trial 3 (yimitasvir phosphate capsules with rosuvastatin calcium tablets), and included 14 subjects. The plasma concentrations of yimitasvir phosphate, sofosbuvir and their main metabolites GS-331007, omeprazole and rosuvastatin were validated by a liquid chromatography/tandem mass spectrometry (LC-MS/MS). The pharmacokinetic parameters were calculated by Phoenix winNonlin software. Results: (1) in trial 1, after single and co-administration, the 90% CI of sofosbuvir C(max) and AUC(0-tau) geometric mean ratio (GMR) were 152.0% (118.0% ~ 197.0%) and 230.0% (184.0% ~ 287.0%), with an increase of 52.0% and 130.0% compared to single dose of sofosbuvir, respectively. The 90% CI of GS-331007 C(max) GMR was 74.0% (67.5% ~ 81.2%) and reduced by 26% compared to single dose of sofosbuvir. (2) in trial 2, the 90% CI of C(max) GMR after yimitasvir single or co-administration at the same time, with a 4-hours interval, or with a 12- hours interval were 68.9% (44.5% ~ 106.7%) , 64.0% (43.8% ~ 93.6%) and 56.4%(38.9% ~ 81.9%), and the 90% CI of AUC(0-t) GMR were 68.6% (46.5% ~ 101.2%), 68.3% (47.6% ~ 98.0%) and 60.5% (41.8% ~ 87.5%), respectively. Compared with single dose of yimitasvir, the C(max) and AUC(0-t) were decreased by 31.1% and 31.4%, 36.0% and 31.7%, 43.6% and 39.5%, respectively. (3) In trial 3, after single and co-administration, the 90% CI of rosuvastatin C(max) and AUC(0-72) GMR were 172.4% (153.6% ~ 193.5%) and 158.0% (144.3% ~ 172.9%), respectively, with an increase of 74.9% and 60.5% compared to single dose of rosuvastatin. There were no serious adverse events and adverse events leading to withdrawal from the trial. Conclusion: Yimitasvir phosphate capsules have drug-drug interactions with sofosbuvir tablets, omeprazole magnesium enteric-coated tablets, and rosuvastatin calcium tablets.

MRI findings of central nervous system involvement in children with haemophagocytic lymphohistiocytosis: correlation with clinical biochemical tests

AIM

To investigate the brain magnetic resonance imaging (MRI) features of children with haemophagocytic lymphohistiocytosis (HLH) with central nervous system (CNS) involvement, and to investigate the correlation with clinical biochemical tests.

MATERIAL AND METHODS

Clinical and MRI data were collected from 118 children with HLH-CNS between January 2012 and June 2019. Patients were grouped according to their MRI findings, and statistical methods were used to test for correlations between the MRI findings and biochemical variables.

RESULTS

Patients were divided into three groups, including normal appearance (Group 1, 17/118), diffuse parenchymal volume loss (Group 2, 44/118), and brain parenchyma lesions (Group 3, 57/118) containing three subtypes of brain lesions and HLH-CNS complications. Comparing biochemical values among the three groups revealed a significant difference for all values (p<0.05), except for cell counts in the cerebrospinal fluid (CSF). A pairwise comparison further showed significant inter-group differences for most of the variables. Spearman's rank correlation coefficient also demonstrated that CSF cell counts (r=0.193, p=0.036), CSF microprotein content (r=0.379, p<0.001), serum aspartate aminotransferase (AST; r=0.521, p<0.001), serum lactate dehydrogenase (LDH; r=0.514, p<0.001) and activated partial thromboplastin time (APTT; r=0.326, p<0.001) correlated positively with the MRI groups, while platelet count (PLT; r=-0.633, p<0.001) and plasma fibrinogen (FIB; r=-0.258, p=0.005) correlated negatively.

CONCLUSION

Classification of brain MRI findings of HLH-CNS correlates well with the results of several key biochemical tests. Brain MRI is a promising method to elucidate illness severity and clinical outcomes.

[A case of difficult extubation after tracheotomy in a child with severe scald of oropharynx]

In November 4, 2016, a 1 year and 3 months old male patient with face and neck scald complicated with severe scald of oropharynx was admitted to Guangzhou Red Cross Hospital 1 hour after injury. The child developed upper respiratory tract obstruction 2 hours after injury, therefore tracheotomy and intubation were performed immediately to establish an artificial airway, and symptomatic treatments such as anti-infection, fluid replacement, and dressing change were conducted. On the 10th day after injury, the child had difficult breathing during the test tube blocking before extubation, and it was difficult to extubate. Symptomatic treatments such as ventilator assisted ventilation and strengthened anti-infection were continued. On the 17th day after injury, extubation plan was adjusted. Thirty minutes before extubation, phenobarbital was injected intramuscularly for sedation, and atropine was used to reduce airway secretions, after which extubation was successful. After 21 days of treatment, the child was cured and discharged. In the treatment of this case, high attention was paid to the important influence of children's mental factors among causes of difficult extubation, which provided a reference for clinical treatment of extubation in children with tracheal tube after tracheotomy.

[Clinical characteristics, treatment and prognosis of myelin oligodendrocyte glycoprotein antibody-associated optic neuritis in children]

Objective: To investigate the clinical characteristics, treatment and prognosis of myelin oligodendrocyte glycoprotein antibody-associated optic neuritis (MOG-ON) in pediatric patients. Methods: Clinical data, laboratory examination, the initial best corrected visual acuity (BCVA), fundus, neuroelectrophysiological results, MRI imaging, treatment and prognosis of children diagnosed with MOG-ON from 2016 to 2019 were retrospectively analyzed. Results: A total of 29 eyes from 16 children were involved, with a male/female ratio of 1∶1, onset age of (7.0±2.9) years. Seven of 16 patients had prodromal infection, with a unilateral/bilateral ratio of 3∶13, and 2 cases had recurrent optic neuritis. Before treatment, BCVA of 19 eyes (65.5%) was ≤0.1, among them, 4 had no sense of light, 5 had light sense, 5 with sense of hands in front of eyes, and 5 with sense of fingers in front of eyes. There were 10 eyes (34.5%) with BCVA of 0.1-0.5. After treatment, there were 4 eyes (13.8%), 5 eyes (17.2%) and 20 eyes (69.0%) in groups with BCVA of 0.1-0.5, 0.5-1.0, and>1.0, respectively. Twelve of 16 patients had optic papillitis in fundus examination during acute phase. The latency was prolonged and the amplitude was decreased in P100 wave of all the children. Thirteen out of 16 children showed swelling and thickening of optic nerve in MRI T2WI. MRI images exhibited intracranial demyelinating lesions in 12 of 16 children and long segment spinal cord lesions in 3 of 16 children. Thirteen of 16 patients showed effective results after intravenous methylprednisolone (IVMP) and intravenous immunoglobulin (IVIG) treatment. There was no relapse after administration of mycophenolate mofetil in 2 recurrent children. No progression after administration of rituximab was found in 1 child with corticosteroid insensitivity. The average follow-up time was (16±9) months and no recurrence occurred. Ten of 16 patients had full recovery, 4 had significant improvement, and 2 showed no significant improvement. Conclusions: There is no significant gender difference in the incidence of pediatric MOG-ON. Bilateral involvement and severe visual impairment are common in acute phase. Most patients have good response to IVMP combined with IVIG treatment and hence have a good prognosis. Only a few of them have neurological sequelae.

[Study on the effect of diallyl sulfide on peripheral nerve injury in n-hexane intoxicated rats]

Objective: To investigate the antagonistic effect of diallyl sulfide (DAS) against peripheral nerve injury induced by n-hexane in rats. Methods: A total of 68 adult male Wistar rats were selected, among which 50 were randomly selected and divided into blank control group, DAS control group (100 mg/kg·bw) , n-hexane model group, low-dose DAS intervention group (50 mg/kg·bw) , and high-dose DAS intervention group (100 mg/kg·bw) . A rat model of peripheral nerve injury was established by n-hexane exposure, and the rats were treated with DAS at different doses. The changes in pyrrole adducts and behavior were observed, a metabolic analysis was performed for serum pyrrole adducts, and the intervention effect was evaluated. The remaining 18 rats were randomly assigned to the n-hexane model group, the low-dose DAS intervention group, and the high-dose DAS intervention group, with 6 rats in each group, as satellite groups used for the toxicokinetic analysis of serum pyrrole adducts. Results: Compared with the blank control group, the n-hexane model group and low-and high-dose DAS intervention groups had a significant reduction in body weight since week 2 (P<0.01) . Compared with the n-hexane model group at the end of the experiment at week 7, the high-dose DAS intervention group had a significantly higher body weight (P<0.05) , while there was no significant difference in body weight between the n-hexane model group and the low-dose DAS intervention group (P>0.05) . The n-hexane model group developed gait abnormality at week 2 of poisoning, while the low-and high-dose DAS intervention groups developed gait abnormality at weeks 3 and 5 of poisoning, respectively. At the end of the experiment, the n-hexane model group and the low-and high-dose DAS intervention groups had a significantly higher gait score than the blank control group (P<0.01) . At the end of the experiment, the n-hexane model group and the low-dose DAS intervention group had significantly shorter latency in rotarod test than the blank control group (P<0.01) , while there was no significant difference in latency between the DAS control group and the high-dose DAS intervention group (P>0.05) . Compared with the n-hexane model group, the low-and high-dose DAS intervention groups had a significant increase in latency in rotarod test (P<0.01) . Compared with blank control group, the n-hexane model group and the low-dose DAS intervention group had a significant increase in mean nerve conduction velocity (P<0.01) , while there was no significant difference between the blank control group and the DAS control group or high-dose DAS intervention group (P>0.05) , and compared with the n-hexane model group, the low-and high-dose DAS intervention groups had a significant increase in nerve conduction velocity (P<0.01) . Compared with the blank control group at the end of the experiment at week 7, the n-hexane model group and the low-and high-dose DAS intervention groups had significant increases in the concentration of pyrrole adducts in serum, urine, and hair (P<0.01) , while there was no significant difference between the blank control group and the DAS control group (P>0.05) , and the high-dose DAS intervention group had a significantly lower concentration of pyrrole adducts in serum, urine, and hair than the low-dose DAS intervention group (P<0.05) . Serum pyrrole adducts reached the peak level at 9-12 hours and then started to decrease. Compared with the n-hexane model group, the high-and low-dose DAS intervention groups had a significantly shorter half-life period of serum pyrrole adducts (P<0.01) . Compared with the n-hexane model group, the high-and low-dose DAS intervention groups had a significant reduction in the area under the curve of serum pyrrole adducts (P<0.05) . Conclusion: DAS can antagonize peripheral nerve injury induced by n-hexane.

Quantitative Analysis of DCE-MRI and RESOLVE-DWI for Differentiating Nasopharyngeal Carcinoma from Nasopharyngeal Lymphoid Hyperplasia

To explore the ability of quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) analysis and readout segmentation of long variable echo-trains diffusion weighted imaging (RESOLVE-DWI) to distinguish nasopharyngeal carcinoma (NPC) from nasopharyngeal lymphoid hyperplasia (NPLH). Twenty-five patients with NPC and 30 patients with NPLH were evaluated. Three quantitative DCE-MRI parameters (Ktrans, Kep and Ve) and the apparent diffusion coeffcient (ADC) of lesions were calculated. The two independent samples t test or Mann-Whitney U test was used to compare the parameters between NPC and NPLH group. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic ability for distinguishing NPC from NPLH. A P value less than 0.05 was considered statistically significant. The difference in Ktrans value between the NPC group and the NPLH group was statistically significant, and the value of the NPC group was larger than that of the NPLH group. There was no statistical difference in Kep and Ve between the two groups. The ADC value of NPC group was smaller than that of NPLH group, and the difference was statistically significant. ROC curve analysis showed that both Ktrans and ADC were effective in diagnosing NPC and the area under the curve (AUC) was 0.773 and 0.704, respectively. In addition, the combination of Ktrans and ADC demonstrated the obviously improved AUC of 0.884. DCE-MRI and RESOLVE-DWI are effective in differentiating NPC from NPLH, especially the combination of the two models.

[Clinical features and prognosis of pediatric myelin oligodendrocyte glycoprotein antibody associated acute disseminated encephalomyelitis]

Objective: To analyze the clinical features, outcome and prognosis of pediatric myelin oligodendrocyte glycoprotein (MOG) antibody associated acute disseminated encephalomyelitis (ADEM), and provide evidence for improving the diagnosis and treatment of this disease. Methods: This study involved 30 MOG antibody-associated ADEM patients in the Department of Neurology, Guangzhou Women and Children's Medical Center. Patients' clinical information were analyzed. Results: The mean onset age was (5.2±3.3) years old, the ration of male to female was 16∶14. Fifty percent of these patients had a history of precede infection or vaccination before onset. Encephalopathy and seizures were the most common clinical manifestations, followed by movement disorder. In addition, some patients had other positive autoantibodies. Brain Magnetic resonance imaging (MRI) showed extensive, asymmetrical, indefinite large patchy lesions in bilateral cortical and subcortical areas and the spinal cord was characterized by long segmental myelitis. In acute attack, the patients had a good response to corticosteroid combined immunoglobulin therapy. Most of these patients had a good prognosis and recurrence rate was about 20%. Conclusions: The onset age of MOG antibody-associated ADEM is around 5 years old. Encephalopathy and seizures were the most common clinical manifestations. Most patients have a good response to corticosteroid combined immunoglobulin therapy. Some patients may have a recurrent disease course.

[Application of meticulous anatomy skills with straight bipolar electric coagulation forceps in thyroid surgery]

Objective: To compare the efficacies of the two techniques of "micro-hemostasis and micro-cutting" with straight bipolar electrocoagulation forceps and traditional clamp-ligation for hemostasia in thyroid surgery. Methods: A total of 228 patients who underwent surgical treatment for thyroid neoplasms in our hospital between January 2015 and December 2018 were retrospectively analyzed, including 50 males and 178 females, aged 23-68 years old. Of those, 150 cases as electric knife group received traditional thyroid surgery between January 2015 and December 2018 and 78 cases as bipolar electrocoagulation group received thyroid surgery by using the technique of bipolar electrocoagulation with meticulous anatomy between January 2018 and December 2018. The total operation time, single operation time, intraoperative hemorrhage, postoperative drainage volume on the first day, postoperative hoarseness and hypocalcemia were compared between the two groups. SPSS 16.0 was used to analyze the data. Results: The total operation time and intraoperative hemorrhage in the bipolar electrocoagulation group were significantly lower than those in the electric knife group ((59.33±18.29)min vs (77.21±25.39)min, (14.83±9.22)ml vs (36.86±11.80)ml, all P<0.01). The single operation time of the bipolar electrocoagulation group was shorter than that of the electric knife group((10.25±6.16) min vs (20.34±7.24)min, (16.25±7.15)min vs (35.68±8.25)min, (12.12±5.25)min vs (20.68±7.26)min, t value was 3.948,16.262,8.238, all P<0.01).There was no significant difference between the two groups in postoperative drainage volume on the first day (P>0.05) and the incidence of postoperative hoarseness (P>0.05), while the incidence of hypocalcemia in the bipolar electrocoagulation group(10.26%) was lower than that in the electric knife group(21.33%,χ(2)=4.353, P<0.05). Conclusions: The fine dissection for thyroid operation can be achieved by using straight bipolar electrocoagulation tweezers. The use of "micro-hemostasis" and "micro-cutting" technique with bipolar electrocoagulation tweezers can greatly reduce intraoperative bleeding, operation time and postoperative complication.

[Antioxidant mechanism of diallyl sulfide in inhibiting leucopenia in peripheral blood induced by benzene in rats]

Objective: To investigate the antioxidant mechanism of diallyl sulfide (DAS) in antagonizing the reduction in peripheral blood white blood cells (WBC) induced by benzene in rats. Methods: A total of 60 specific pathogen-free adult male Sprague-Dawley rats, with a body weight of 180-220 g, were selected, and after 5 days of adaptive feeding, they were randomly divided into blank control group, DAS control group, benzene model group, benzene+low-dose DAS group, benzene+middle-dose DAS group, and benzene+high-dose DAS group, with 10 rats in each group. The rats in the benzene+low-dose DAS group, the benzene+middle-dose DAS group, the benzene+high-dose DAS group, and the DAS control group were given DAS by gavage at a dose of 40, 80, 160, and 160 mg/kg·bw, respectively, and those in the blank control group and the benzene model group were given an equal volume of corn oil; 2 hours later, the rats in the benzene model group, the benzene+low-dose DAS group, the benzene+middle-dose DAS group, and the benzene+high-dose DAS group were given a mixture of benzene (1.3 g/kg·bw) and corn oil (with a volume fraction of 50%), and those in the blank control group and the DAS control group were given an equal volume of corn oil. The above treatment was given once a day for 4 consecutive weeks. At 1 day before treatment, anticoagulated blood was collected from the jugular vein for peripheral blood cell counting. After anesthesia with intraperitoneally injected pentobarbital (50 mg/kg·bw), blood samples were collected from the abdominal aorta, serum was isolated, and the thymus, the spleen, and the femur were freed at a low temperature to measure oxidative and antioxidant indices. The femur at one side was freed for WBC counting in bone marrow. Results: Compared with the blank control group, the benzene model group had significant reductions in the volume, weight, and organ coefficient of the spleen and the thymus (P<0.05) ; compared with the benzene model group, the benzene+low-dose DAS group, the benzene+middle-dose DAS group, and the benzene+high-dose DAS group had significant increases in the volume of the spleen and the thymus and the weight and organ coefficient of the spleen (P<0.05), and the benzene+middle-dose DAS group and the benzene+high-dose DAS group had significant increases in the weight and organ coefficient of the thymus (P<0.05). Compared with the blank control group, the benzene model group had a significant reduction in WBC count in peripheral blood and bone marrow (P<0.05), and compared with the benzene model group, the benzene+middle-dose DAS group and the benzene+high-dose DAS group had a significant increase in WBC count in peripheral blood and bone marrow (P<0.05). Compared with the blank control group, the benzene model group had a significant increase in the serum level of malondialdehyde (MDA) (P<0.05) and significant reductions in total superoxide dismutase (T-SOD) activity, reduced glutathione (GSH) level, GSH/oxidized glutathione (GSSG) ratio, total antioxidant capacity (T-AOC) (P<0.05) ; compared with the benzene model group, the benzene+high-dose DAS group had a significant reduction in the serum level of MDA and significant increases in T-SOD activity, GSH level, GSH/GSSG ratio, and T-AOC (P<0.05). Compared with the blank control group, the benzene model group had a significant increase in the level of MDA (P<0.05) and significant reductions in GSH level, GSH/GSSG ratio, and T-AOC (P<0.05) in the spleen; compared with the benzene model group, the benzene+low-dose DAS group, the benzene+middle-dose DAS group, and the benzene+high-dose DAS group had a significant reduction in MDA level (P<0.05) and significant increases in GSH level and T-AOC (P<0.05), and the benzene+high-dose DAS group had significant increases in T-SOD activity and GSH/GSSG ratio (P<0.05). Compared with the blank control group, the benzene model group had a significant increase in the level of MDA in bone marrow cells (BMCs) and peripheral blood mononucleated cells (PBMCs) (P<0.05) and a significant reduction in T-AOC in PBMCs (P<0.05) ; compared with the benzene model group, the benzene+low-dose DAS group, the benzene+middle-dose DAS group, and the benzene+high-dose DAS group had a significant reduction in the level of MDA in BMCs and PBMCs (P<0.05), and the benzene+high-dose DAS group had significant increases in GSH level and GSH/GSSG ratio (P<0.05) . Conclusion: DAS can antagonize the benzene-induced reduction in peripheral blood WBC, possibly by exerting an anti-oxidative stress effect.

[Diagnostic performance of ultrasound-based risk stratification systems for indeterminate thyroid nodules: comparison of the 2015ATA guidelines with the 2016 KTA/KSThR and 2017ACR guidelines]

Objective: To evaluate the diagnostic value of the 2015ATA, 2017ACR and 2016KTA/KSThR ultrasound model for indeterminate thyroids nodules. Method: Four hundred and sixty-four patients with thyroid nodules that were initially diagnosed as indeterminate thyroids nodules by fine needle aspiration(FNA) cytology were included in this study. The clinical data and two-dimensional ultrasonographic features were compared between the benign and malignant nodules. The two-dimensional ultrasound images of all nodules were sorted by the 2015ATA, 2017ACR and 2016KTA/KSThR guideline ultrasound model grading criteria, and the malignant risk of different grading were calculated. In order to calculate the diagnosis and other indicators, the optimal threshold drawing from ROC curve was drawn to obtain the cut-off value of 2015ATA, 2017ACR and 2016KTA/KSThR. Result: ①There was no significant difference in age, sex and nodule size between benign and malignant nodules(P>0.05), and there also was no significant difference in irregular margin, microcalcification between benign and malignant nodules.②The sensitivity of the 2015ATA ultrasound model was 87.9%, slightly lower than that of the 2016KTA/KSThR and 2017ACR guidelines(P>0.05).The specificity of 2015ATA was 63.9%, which was significantly higher than that of 2016KTA/KSThR and 2017ACR guidelines(P<0.05). There was no significant difference between 2015ATA ultrasound model and 2016KTA/KSThR guide ultrasound for the accuracy(P>0.05), but the accuracy of 2015ATA ultrasound model was significantly higher than that of 2017ACR guide(P<0.05).③The area under the curve of 2015ATA was slightly lower than that of 2016KTA/KSThR(0.889 VS 0.902, P>0.05) and significantly higher than that of 2017ACR(0.889 VS 0.854, P<0.05). Conclusion: 2015ATA has high specificity and accuracy and moderate sensitivity for the diagnosis of benign and malignant indeterminate thyroids nodules, which is helpful for the clinical evaluation and management of such nodules.

[Analysis of causes and treatment methods of complication of early acute kidney injury in four severely burned patients]

Objective: To analyze the causes of complication of early acute kidney injury (AKI) in four severely burned patients, and to explore the related treatment methods. Methods: The clinical data of 4 patients with severe burn complicated with early AKI admitted to Guangzhou Red Cross Hospital Affiliated to Medical College of Jinan University (hereinafter referred to as our hospital) from June 2014 to December 2017 were retrospectively analyzed. All the patients were male, aged 23-33 (30±5) years old, with depth of burns ranged from deep partial-thickness to full-thickness, complicated with myofascial compartment syndrome of extremities and varying degrees of striated muscle injury, and treated in other hospitals before transfer to our hospital. The patients were numbered from small to large according to the total burn area. The total burn area of patients No. 1, 2, 3, and 4 was 10%, 80%, 90%, and 95% total body surface area respectively, their occurrence time of early AKI was 48, 11, 29, and 48 hours after injury respectively, and their time of arriving our hospital was 60, 11, 29, and 144 hours after injury respectively. Hypovolemic shock occurred in patients No. 2 and 3 at admission to our hospital. All the patients received continuous renal replacement therapy (CRRT) after admission to our hospital. Under the support of hemodynamic monitoring and organ function monitoring, the limbs complicated with myofascial compartment syndrome were incised, thorough decompression exploration was performed, and necrotic muscle tissue was removed or amputation was performed. After escharectomy and decompression of limbs, fresh granulation wounds were formed by temporarily covering wounds with Jieya dressing skin or pig skin, multiple debridements, and vacuum sealing drainage. Fresh granulation wounds and other wounds underwent staged eschar excision and shaving were covered with autologous Meek skin graft, particulate skin graft, reticular skin graft and small skin graft respectively. The treatment outcome, CRRT time, operation times, time of recovery of serum creatinine and myoglobin, length of hospital stay, and follow-up were recorded. Results: All the 4 patients were cured after transfer to our hospital. Among them, totally 5 limbs of patients No. 1 and No. 4 underwent amputation because of complication of myofascial compartment syndrome and a large amount of necrotic muscle which could not be preserved. Patients No. 1, 2, 3, and 4 were treated with CRRT for 19, 35, 14, and 25 days respectively and performed with operation for 5, 6, 10, 8 times respectively. Serum creatinine of patients No. 1, 2, 3, and 4 returned to normal on 22, 35, 37, and 48 days after transfer respectively, and their serum myoglobin returned to normal on 18, 28, 25, and 30 days after transfer respectively. Patients No. 1, 2, 3, and 4 were hospitalized for 52, 105, 148, and 156 days and discharged after basic wound healing. Follow-up for 1 to 36 months showed no abnormal renal function in 4 patients. Conclusions: The early AKI in patients No. 1 and 4 was caused by rhabdomyolysis after severe burn complicated with myofascial compartment syndrome, while that of the other 2 cases were also related to hypovolemic shock and poor renal perfusion. The success rate of early AKI treatment in severely burned patients can be effectively improved by removing the causes of diseases at the same time of CRRT and actively treating burn wounds under the support of organ function and hemodynamic monitoring.

Greenhouse gas fluxes at different growth stages of biological soil crusts in eastern Hobq desert, China

We analyzed greenhouse gas fluxes at the different growth stages of algae and lichen crusts in fixed sand with mobile dune as control in the eastern Hobq Desert, China, using the spatio-temporal substitution method. We explored the correlation of these fluxes with environmental factors and with biological soil crust growth. The results showed that variation of CO₂ fluxes followed the order: lichen crust (128.5 mg·m^-2·h^-1) > algae crust (70.2 mg·m^-2·h^-1) > mobile dune (48.2 mg·m^-2·h^-1). CH₄ absorption rates were in the following order: lichen crust (30.4 μg·m^-2·h^-1) > algae crust (21.2 μg·m^-2·h^-1) > mobile dune (18.2 μg·m^-2·h^-1). The N₂O fluxes were in the following order: lichen crust (6.6 μg·m^-2·h^-1) > algae crust (5.4 μg·m^-2·h^-1) > mobile dune (2.5 μg·m^-2·h^-1). CO₂ emission had obvious seasonal variation, with higher emission in the growing season. CH₄ and N₂O fluxes had no seaonal variation. CH₄ absorption mainly occurred in the growing season and N₂O emission mainly occurred in non-growing season. Contents of soil total nitrogen and organic carbon and the abundance of microorganisms were important factors affecting greenhouse gas fluxes. Hydrothermic factors were important for soil CO₂ emission, but not for CH₄ and N₂O fluxes. The cumulative greenhouse gas emissions were gradually increased with vegetation restoration and the development of biological soil crust. The global warming potential increased following an order: lichen crust (1135.7 g CO₂-e·m^-2·a^-1) > algae crust (626.5 g CO₂-e·m^-2·a^-1) > mobile dune (422.7 g CO₂-e·m^-2·a^-1).

[Determination of ethylenediamine in the air of workplace by Ion chromatography]

Objective: To establish a method to detect the concentrations of ethylenediamine in the air of workplace by Ion chromatography. Methods: Ethylenediamine in the air of workplace adsorpted by Silicone tube, then ultrasonic desorped by Sulfuric acid solution (0.1 mol/L) , the desorption solution qualitative and quantitative determination by Ion chromatography. Results: For ethylenediamine, the calibration curves were liner in the range of 0.1-100.0 μg/ml, the method detection limit is 0.1 μg/ml, the minimum detectable concentration is 0.13 mg/m(3) (in terms of sampling 7.5 L) . The desorption efficiency is more than 90% on spiked levels of 2.0, 4.0 and 8.0 μg/ml, the average desorption efficiency of the method was 96.1%, the precision was 1.8%-2.1%. The recovery rate of the added standard is 98.5%-104.2%. Conclusion: The method simplifies the preprocessing steps and improves the sensitivity. All the indexes are in conformity with the requirements of the method formulation guide. It is suitable for the determination of ethylenediamine in the air of the workplace.

[Establishment and optimization of hepatocyte steatosis model]

Objective: To establish a new model of hepatic steatosis cells by optimizing the original ethanol or high fat, the present study proposed an in vitro hepatocyte steatosis model for the study of fatty liver. Methods: Oil red O staining was used to observe the effects of fetal bovine serum, oleic acid and ethanol on lipid accumulation in human liver cell line L02 in a concentration- and time-dependent manner. RT-PCR was used to detect the mRNA expression levels of PPAR-γ and AP-2, and the suitable conditions for the establishment of hepatocyte steatosis model were screened out. A t-test was used for comparison between the two groups, and one-way Analysis of Variance (ANOVA) was used in more than three groups. Results: Oil red O staining showed the number of reddish-orange lipid droplets in L02 cells gradually increased with the increase of fetal bovine serum, oleic acid and ethanol in a concentration - and time-dependent manner. Compared with 0.00% oleic acid and 2% ethanol, the count value of red particle was 100.00% ± 17.63% at the beginning and after 24 h, 0.003% oleic acid and 2% ethanol jointly acted in L02 cells. After incubation for 48 hours with 2% ethanol and serum-free DMEM medium, the accumulation of lipid droplets was the highest with a count value of 802.38%+71.06%(t = 42.36, P < 0.001). RT-PCR analysis showed the lipid accumulation induced by this method was positively correlated with the mRNA expression of PPAR-γ and AP-2. Conclusion: L02 cells were successfully exposed to high fat and ethanol, and the hepatocyte steatosis model was established and optimized, suggesting that the occurrence of hepatic cell steatosis was related to the up-regulation of PPAR-γ and AP-2.

[Effect of GSK-3β inhibitor on the expression of RANK-RANKL in rats kidney tissue with diabetic nephropathy]

Objective: To investigate the effect and significance of GSK-3β inhibitor(LiCl)and RANK-RANKL on the renal tissue of diabetic nephropathy(DN) rats. Methods: SD rats were divided into normal control group (NC), DN model group (DN) and GSK-3β inhibitor intervention group (LiCl). Twenty-four hour urine protein of rats were determined by Coomassie brilliant blue. Kidney tissue sections were stained by HE. The expression of GSK-3β, RANK and RANKL protein were determined by immunohistochemistry staining. The mRNA of GSK-3β, RANK, RANKL was detected by RT-qPCR. Results: Compared with NC group[(14.72±3.37)g], the level of 24-hour urinary protein[(154.17±20.65)g] increased significantly in DN group; compared with DN Group, the level of 24-hour urinary protein [(107.22±31.15)g]decreased in LiCl group(P<0.05). Compared with NC group(2.10±0.60, 1.10±0.20, 1.21±0.20; 19.52±3.20, 1.80±1.10, 1.81±0.50), the pathological changes of renal tissues of DN group aggravated, the mRNA and expression of protein of GSK-3β, RANK and RANKL increased(9.10±2.15, 8.95±2.40, 9.90±2.60; 32.70±7.20, 19.20±4.32, 20.92±5.90); compared with DN group, the pathological changes of renal tissues of LiCl group alleviated, mRNA and the expression of protein of factors above declined(2.70±0.80, 2.32±0.65, 3.58±1.10; 22.35±3.25, 4.20±2.42, 5.90±2.36; P<0.05). Conclusion: RANK and RANKL play an important role in the development of DN, LiCl influence Wnt and NF-κB signal pathway down-regulating RANK and RANKL to suspend development of diabetic nephropathy.

[The clinical characteristics of 346 patients with IgG4-related disease]

Objective: To analyze the clinical characteristics of IgG₄-related disease (IgG₄-RD)so as to improve the understanding of IgG₄-RD in China. Methods: IgG₄-RD patients were recruited from Peking Union Medical College Hospital between January 2011 and January 2016. All patients were followed-up for more than 6 months. The demographic characteristics, symptoms, organ involvements, laboratory examinations and treatment efficacy were evaluated and analyzed. Results: A total of 346 patients were finally enrolled, including 230 males (66.5%) and 116 females (33.5%). The mean age of disease onset was (53.8±14.2) years old. The mostly common involved organs were lymph nodes (56.4%) and submandibular glands (52.6%). Other affected organs and manifestations included: swelling of the lacrimal glands (46.5%), autoimmune pancreatitis (38.4%), pulmonary involvement (28.0%), sclerosing cholangitis (25.4%), naso-sinusitis (23.4%), parotid gland swelling (21.7%), retroperitoneal fibrosis (19.9%), large arteries involvement (9.5%), kidney involvement (obstructive nephropathy caused by retroperitoneal fibrosis was excluded) (6.9%), skin lesions (6.4%). Rare features consisted of thyroid glands, pituitary glands, gastrointestinal tract, pachymeningitis, pericardium, sclerosing mediastinitis and orchitis. The majority of patients had multi-organ involvement, such as 74.3% patients with 3 and more, 18.2% and 7.5% patients with 2 and single organ involvement respectively. The average IgG₄-RD responder index (IgG₄-RD RI) was 13.21±5.70. History of allergy was found in 172 (49.7%) patients. As to the laboratory tests, elevated serum IgG₄ levels were confirmed in 285 (94.1%) patients, which was positively correlated with IgG₄-RD RI. There were 33.5% patients receiving monotherapy of glucocorticoid, 52.6% treated with glucocorticoids combined with immunosuppressive agents, 4.9% patients with immunosuppressant only, and 9.0% patients with mild disease not receiving medication. The majority (336, 97.1%) patients improved the above regimens. Conclusion: IgG₄-RD is a systemic fibro-inflammatory disease with multiple organ involvement. The mostly common involved organs include lymph node, submandibular glands, and pancreas. Glucocorticoids and immunosuppressive agents were effective for IgG₄-RD.