[Clinical characteristics and prognosis of 8 cases of severe infant botulism]

Objective: To summarize the clinical characteristics and prognosis of severe infant botulism and evaluate the therapeutic effect of botulinum antitoxin in the pediatric intensive care unit (PICU). Methods: The clinical data of 8 cases diagnosed with infantile botulism were retrospectively analyzed in the PICU of Beijing Children's Hospital from October 2019 to August 2023. Data of basic demographic information, clinical manifestations, laboratory tests, treatment and prognosis of each child were collected and analyzed using descriptive statistical methods. Results: Eight laboratory-confirmed cases of infant botulism were included in this study, all of which were male infants with an age of 6.0 (3.3,6.8) months. Three of the children were from Inner Mongolia Autonomous Region, 2 of them were from Hebei, and the other 3 were from Beijing, Shandong and Xinjiang Uyghur Autonomous Region, respectively. All the patients were previously healthy. In 4 of these cases, the possible cause was the ingestion of either honey and its products or sealed pickled food by the mother or child before the onset of the disease. The first symptom was poor milk intake (4 cases), followed by shallow shortness of breath (7 cases), limb weakness (7 cases) and so on. The typical signs were bilateral dilated pupils (8 cases) and decreased limb muscle strength (8 cases). The main subtype was type B (7 cases), and only 1 case was classified as type A. Six of the children were treated with antitoxin therapy for a duration of 24 (19, 49) d. Seven of them had invasive mechanical ventilation. All the patients survived upon discharge with a follow-up period of 29 d to 3 years and 8 months. Six patients had fully recovered, and 2 recently discharged patients were gradually recovering. Conclusions: For infants with suspected contact or ingestion of botulinum and presented with bilateral pupillary paralysis, muscle weakness and clear consciousness, the stool should be collected for diagnostic testing using a mouse bioassay as soon as possible. Type B was the most common type. The antitoxin treatment was effectiveness and the prognosis was well.

[Respiratory virus infection and its influence on outcome in children with septic shock]

Objective: To investigate respiratory virus infection in children with septic shock in pediatric care units (PICU) in China and its influence on clinical outcomes. Methods: The clinical data of children with septic shock in children's PICU from January 2018 to December 2019 in 10 Chinese hospitals were retrospectively collected. They were divided into the pre-COVID-19 and post-COVID-19 groups according to the onset of disease, and the characteristics and composition of respiratory virus in the 2 groups were compared. Matching age, malignant underlying diseases, bacteria, fungi and other viruses, a new database was generated using 1∶1 propensity score matching method. The children were divided into the respiratory virus group and non-respiratory virus group according to the presence or absence of respiratory virus infection; their clinical characteristics, diagnosis, and treatment were compared by t-test, rank sum test and Chi-square test. The correlation between respiratory virus infection and the clinical outcomes was analyzed by logistic regression. Results: A total of 1 247 children with septic shock were included in the study, of them 748 were male; the age was 37 (11, 105) months. In the pre-and post-COVID-19 groups, there were 530 and 717 cases of septic shock, respectively; the positive rate of respiratory virus was 14.9% (79 cases) and 9.8% (70 cases); the seasonal distribution of septic shock was 28.9% (153/530) and 25.9% (185/717) in autumn, and 30.3% (161/530) and 28.3% (203/717) in winter, respectively, and the corresponding positive rates of respiratory viruses were 19.6% (30/153) and 15.7% (29/185) in autumn, and 21.1% (34/161) and 15.3% (31/203) in winter, respectively. The positive rates of influenza virus and adenovirus in the post-COVID-19 group were lower than those in the pre-COVID-19 group (2.1% (15/717) vs. 7.5% (40/530), and 0.7% (5/717) vs. 3.2% (17/530), χ2=21.51 and 11.08, respectively; all P<0.05). Rhinovirus virus were higher than those in the pre-Covid-19 group (1.7% (12/717) vs. 0.2% (1/530), χ2=6.51, P=0.011). After propensity score matching, there were 147 cases in both the respiratory virus group and the non-respiratory virus group. Rate of respiratory failure, acute respiratory distress, rate of disseminated coagulation dysfunction, and immunoglobulin usage of the respiratory virus group were higher than those of non-respiratory virus group (77.6% (114/147) vs. 59.2% (87/147), 17.7% (26/147) vs. 4.1% (6/147), 15.6% (25/147) vs. 4.1% (7/147), and 35.4% (52/147) vs. 21.4% (32/147); χ2=11.07, 14.02, 11.06 and 6.67, all P<0.05); and PICU hospitalization of the former was longer than that of the later (7 (3, 16) vs. 3 (1, 7)d, Z=5.01, P<0.001). Univariate logistic regression analysis showed that the presence of respiratory viral infection was associated with respiratory failure, disseminated coagulation dysfunction, the use of mechanical ventilation, and the use of immunoglobulin and anti-respiratory viral drugs (OR=2.42, 0.22, 0.25, 0.56 and 1.12, all P<0.05). Conclusions: The composition of respiratory virus infection in children with septic shock is different between pre and post-COVID-19. Respiratory viral infection is associated with organ dysfunction in children with septic shock. Decreasing respiratory viral infection through respiratory protection may improve the clinical outcome of these children.

[Poisonous substances and geographical distribution of poisoning in hospitalized children based on data from 25 hospitals in China from 2016 to 2020]

Objective: To investigate the poisonous substances and geographical distribution of poisoning in children in China. Methods: A cross-sectional study. The clinical data of 8 385 hospitalized children from January 2016 to December 2020 were extracted from the FUTang Updating Medical Records database. These children aged 0 to 18 years and were admitted due to poisoning. They were grouped according to age (newborns and infants, toddlers, preschoolers, school-age children, adolescents), place of residence (Northeast China, North China, Central China, East China, South China, Southwest China, Northwest China), and mode of discharge (discharge under medical advice, transfer to another hospital under medical advice, discharge without medical advice, death, other). The poisonous substance and causes of poisoning in different groups were analyzed. Results: Among these 8 385 children, 4 734 (56.5%) were male and 3 651 (43.5%) female, with a male-to-female ratio of 1.3∶1. The age was 3 (2, 7) years. The prevalence of poisoning was 51.8% (4 343/8 385) in toddlers, 16.5% (1 380/8 385) in adolescents, 14.8% (1 242/8 385) in preschoolers, 14.4% (1 206/8 385) in school-age children, and 2.5% (214/8 385) in newborns and infants. Drug poisoning accounted for 43.5% (3 649/8 385) and pesticide accounted for 26.8% (2 249/8 385). Drug poisoning was more common in adolescents (684/1 380, 49.6%) and toddlers (2 041/4 343, 47.0%); non-drug poisoning was more common in school-age children (891/1 206, 73.9%), of which carbon monoxide was mainly in newborns and infants (41/214, 19.2%) and food poisoning in children of school age (241/1 206, 20.0%). Regarding regional characteristics, drug poisoning was more frequent in South China (188/246, 64.2%) and non-drug poisoning was more frequent in Southwest China (815/1 123, 72.5%). For drugs, anti-epileptic drugs, sedative-hypnotic drugs and anti-Parkinson's disease drugs had a higher proportion of poisoning in North China (138/1 034, 13.0%) than that in other regions. For non-drug poisoning, pesticides (375/1 123, 33.3%), food poisoning (209/1 123, 18.6%) and contact with poisonous animals (86/1 123, 7.7%) were more common in Southwest China than in other regions; carbon monoxide poisoning was more common in North China (81/1 034, 7.6%) and Northwest China (65/1 064, 6.3%). In Central China, poisoning happened more in toddlers (792/1 295, 61.2%) and less in adolescents (115/1 295, 8.8%) than in other regions. Regarding different age groups, poisoning in adolescent happened more in Northeast China (121/457, 26.5%), North China (240/1 034, 23.2%), and Northwest China (245/1 064, 23.0%). The rate of discharge under medical advice, discharge without medical advice, and mortality rate within the 5 years were 77.0% (6 458/8 385), 20.8% (1 743/8 385), 0.5% (40/8 385), respectively. Conclusions: Poisoning is more common in male and toddlers. Poisonous substances show a regional characteristic and vary in different age groups, with drugs and insecticides as the most common substances.

[Diagnosis and treatment of pediatric septic shock in pediatric intensive care units from hospitals of different levels]

Objective: To investigate the differences in clinical characteristics, diagnosis, and treatment of pediatric septic shock in pediatric intensive care unit (PICU) among hospitals of different levels. Methods: This retrospective study enrolled 368 children with septic shock treated in the PICU of Beijing Children's Hospital, Henan Children's Hospital, and Baoding Children's Hospital from January 2018 to December 2021. Their clinical data were collected, including the general information, location of onset (community or hospital-acquired), severity, pathogen positivity, consistence of guideline (the rate of standard attainment at 6 h after resuscitation and the rate of anti-infective drug administration within 1 h after diagnosis), treatment, and in-hospital mortality. The 3 hospitals were national, provincial, and municipal, respectively. Furthermore, the patients were divided into the tumor group and the non-tumor group, and into the in-hospital referral group and the outpatient or emergency admission group. Chi-square test and Mann-Whitney U test were used to analyze the data. Results: The 368 patients aged 32 (11, 98) months, of whom 223 were males and 145 females. There were 215, 107, and 46 patients with septic shock, with males of 141, 51, and 31 cases, from the national, provincial, and municipal hospitals, respectively. The difference in pediatric risk of mortality Ⅲ (PRISM Ⅲ) scores among the national,provincial and municipal group was statistically significant (26(19, 32) vs.19(12, 26) vs. 12(6, 19), Z=60.25,P<0.001). The difference in community acquired septic shock among the national,provincial and municipal group was statistically significant (31.6%(68/215) vs. 84.1%(90/107) vs. 91.3%(42/46), χ²=108.26,P<0.001). There were no significant differences in compliance with guidelines among the 3 groups (P>0.05). The main bacteria detected in the national group were Klebsiella pneumoniae (15.4% (12/78)) and Staphylococcus aureus (15.4% (12/78)); in the provincial group were Staphylococcus aureus (19.0% (12/63)) and Pseudomonas aeruginosa (12.7% (8/63)), and in the municipal group were Streptococcus pneumoniae (40.0% (10/25)) and Enteric bacilli (16.0% (4/25)). The difference in the proportion of virus and the proportion of 3 or more initial antimicrobials used among the national,provincial and municipal group was statistically significant (27.7% (43/155) vs. 14.9% (13/87) vs. 9.1% (3/33), 22.8%(49/215) vs. 11.2%(12/107) vs. 6.5%(3/46), χ²=8.82, 10.99, both P<0.05). There was no difference in the in-hospital mortality among the 3 groups (P>0.05). Regarding the subgroups of tumor and non-tumor, the national group had higher PRISM Ⅲ (31(24, 38) vs. 22 (21, 28) vs.16 (9, 22), 24 (18, 30) vs. 17(8, 24) vs. 10 (5, 16), Z=30.34, 10.45, both P<0.001), and it was the same for the subgroups of in-hospital referral and out-patient or emergency admission (29 (21, 39) vs. 23 (17, 30) vs. 15 (10, 29), 23 (17, 29) vs. 18 (10, 24) vs. 11 (5, 16), Z=20.33, 14.25, both P<0.001) as compared to the provincial and municipal group. There was no significant difference in the in-hospital mortality among the 2 pairs of subgroups (all P>0.05). Conclusion: There are differences in the severity, location of onset, pathogen composition, and initial antibiotics of pediatric septic shock in children's hospitals of different levels, but no differences in compliance with guidelines and in-hospital survival rate.

Comparison of Uveitis Incidence by Medication in Juvenile Idiopathic Arthritis and Implications for Screening

PURPOSE

To determine uveitis incidence in juvenile idiopathic arthritis (JIA) patients treated with disease-modifying antirheumatic drugs (DMARD) medications, and to evaluate uveitis risk-stratification protocols.

DESIGN

Retrospective clinical cohort study.

METHODS

Medical records of patients with JIA seen by ophthalmology at a single institution from April 2014 to April 2022 and ≥18 months' follow-up were reviewed. Exclusion criteria included uveitis history prior to study period, Still disease, or <18 months' follow-up. Patient characteristics, medications, and uveitis status were recorded. Factors associated with uveitis development were analyzed and statistically significant metrics used to determine empiric risk-stratification criteria. These criteria and American College of Rheumatology (ACR) risk-stratification guidelines were applied retroactively to determine predictive power.

RESULTS

One hundred eighty-four patients met inclusion criteria and were included. Twenty-one new cases of uveitis developed during the study period. There were no statistically significant differences between no DMARD treatment, methotrexate (MTX), and etanercept (ETA) groups in uveitis incidence, whereas the adalimumab (ADA) and other biologics groups had no uveitis cases. Under the empirically determined criteria, the ratio of uveitis incidence between high- and low-risk groups was 8.21 (2.68-33.55; P < .0001), whereas it was 1.90 (0.72-4.93; P = .15) under the ACR criteria.

CONCLUSION

Patients on MTX, ETA, and no DMARD treatment were comparable in JIA-associated uveitis incidence, whereas there were no new cases with ADA or other biologics. Further, we found increased predictive power in the empiric criteria in comparison to current ACR risk stratification.

[Application of initial anti-infectives and trends in children with septic shock]

Objective: To investigate the pathogen composition, initial anti-infectives and pathogen coverage, and trends over the last 5 years in children with septic shock in pediatric intensive care unit (PICU). Methods: The single-center retrospective study included 257 children with septic shock who were admitted to PICU of Beijing Children's Hospital, Capital Medical University from 2017 to 2021. The causitive pathogen composition, initial use of anti-infective drugs, pathogen coverage, and changes in recent years were analyzed. The children were divided into sufficient and insufficient coverage groups according to whether the pathogen were sufficiently covered by initial anti-infectives; community-and hospital-acquired groups; and with and without underlying disease groups. T test, rank-sum test and Chi-square test were used for comparison between the groups to investigate the differences in pathogen, treatment and prognosis. Results: A total of 257 septic shock children were included, with 162 males and 95 females, aged 36 (12, 117) months. The pathogen positive rate was 64.6% (166/257) and the in-hospital mortality was 27.6% (71/257). In the 208 pathogen-positive samples, bacteria was the most common (57.7%, 120/208) with G-negative bacteria predominating (55.8%, 67/120), followed by viruses (26.0%, 54/208). Nearly 99.2% (255/257) of the children were treated with antibacterial at the beginning, of whom 47.1% (121/257) were treated with carbapenems combined with vancomycin or linezolid. The proportion of 3 or more antibacterial combinations was higher in children with underlying diseases and hospital-acquired septic shock than in those without underlying disease or community-acquired septic shock (27.4% (49/179) vs. 14.1% (11/78), 29.4% (52/177) vs. 10.0% (8/80), χ²=5.35,11.56,all P<0.05). The proportion of initial combination of carbapenem and vancomycin or linezolid reduced from 52.5% (21/40) to 41.3% (19/46), and of adequate pathogen coverage increased from 40.0% (16/40) to 58.7% (27/46) in the last five years. Conclusions: The initial use of antibacterial drugs is common in children with septic shock in PICU, especially in those with hospital-acquired septic shock and underlying diseases. In recent years, antimicrobial combinations have decreased, but the pathogen coverage has improved, indicating that drug selection is more reasonable and accurate.

[Clinical analysis of 6 critically ill children with acute chlorine poisoning]

Objective: To analyze the clinical characteristics and treatment of critically ill children with acute chlorine poisoning and explore the risk factors and effective strategies. Methods: This retrospective study collected the clinical data, including general state, clinical characteristics, treatment and follow-up(till 1 year and 6 months after discharge), of 6 critically ill children who were hospitalized in the Pediatric Intensive Care Unit of Beijing Children's Hospital due to acute chlorine poisoning in August 2019. Results: There were 6 children characterized by severe dyspnea in this accident, among whom 4 were boys and two girls, aged 4-12 years. When the accident occurred, they were within 5 m of the chlorine source. These patients underwent tracheal intubation and mechanical ventilation in 3.5-7.0 h after poisoning. The child who was the closest to the chlorine source (1.5 m) and took the longest time (5 min) to evacuate was the most severe one. He suffered hypoxia which could not be corrected by conventional mechanical ventilation and severe shock, then had veno-arterial extracorporeal membrane oxygenation(ECMO) treatment started 10 h after the accident. All the 6 children in this study survived. Following-up found no growth and developmental abnormality. The pulmonary function tests were normal except for one case with increased small airway resistance due to previous suspected asthma, and the lung CT, electhoencephalogram, and brain magnetic resonance imaging were all normal. Conclusions: Severe chlorine poisoning is mainly characterized by respiratory failure. Mechanical ventilation is often required within a few hours after poisoning. When conventional mechanical ventilation is ineffective, ECMO could save live. Timely treatment could improve prognosis.

Prediction for Cycloplegic Refractive Error in Chinese School Students: Model Development and Validation

Purpose

To predict cycloplegic refractive error using measurements obtained under noncycloplegic conditions.

Method

Refractive error was measured in 5- to 18-year-old Chinese students using a NIDEK autorefractor before and after administration of 0.5% tropicamide. Spherical equivalent (SER) in diopters (D) was calculated as sphere plus half cylinder. A multivariable prediction model for cycloplegic SER was developed using data from students in Jinyun (n = 1938) and was validated using data from students in Hangzhou (n = 1498). The performance of the prediction model was evaluated using R², mean difference between predicted and measured cycloplegic SER, and sensitivity and specificity for predicting myopia (cycloplegic SER ≤ −0.5 D).

Results

Among 3436 students (mean age, 9.7 years; 51% female), the mean (SD) noncycloplegic and cycloplegic SER values were −1.12 (1.97) D and −0.20 (2.19) D, respectively. The prediction model that included demographics, noncycloplegic SER, axial length/corneal curvature radius ratio, uncorrected visual acuity (UCVA), and intraocular pressure predicted cycloplegic SER with R² of 0.93 in the development dataset and 0.92 in the validation dataset. The mean (SD) differences between predicted and measured cycloplegic SER were 0.0 (0.55) D in the development dataset and 0.06 (0.64) D in the validation dataset. In both the development and validation datasets, the combination of predicted SER and UCVA yielded high sensitivity (91.4% and 91.9%, respectively) and specificity (95.0% and 90.1%, respectively) for detecting myopia.

Conclusions

Cycloplegic refractive error can be predicted using measurements obtained under noncycloplegic conditions. The prediction model could potentially be used to correct the myopia prevalence in epidemiological studies in which administering cycloplegic agent on all participants is not feasible.

Translational Relevance

The prediction model may provide a tool for correcting the overestimation of myopia from noncycloplegic refractive error in future epidemiological studies in which administering cycloplegic agent on all participants is not feasible.

Effect of Cycloplegia on Refractive Error Measure in Chinese School Students

PURPOSE

To determine differences in cycloplegic vs. non-cycloplegic refractive error and factors associated with these differences in Chinese school students.

METHOD

In this cross-sectional school-based study, refractive error was measured in school students using a NIDEK autorefractor before and after administration of 0.5% tropicamide. Spherical equivalent (SER) in diopters (D) was calculated as sphere plus half cylinder. SER differences before vs. after cycloplegia were evaluated using mean, standard deviation (SD), 95% limits of agreement. Univariable and multivariable regression models were used to determine factors associated with SER differences.

RESULTS

Among 3604 students, 3450 (95.7%) provided data for analysis. Mean age (SD) was 9.7 (3.6) years. The mean SER (SD) was -1.12 (1.97) D before cycloplegia, and -0.20 (2.19) D after cycloplegia, with a mean difference of 0.92 D (95% limits of agreement: -0.93 to 2.78 D). Among 196 eyes with non-cycloplegic SER -6.0 D or worse (e.g., met high myopia definition), 71.4% had cycloplegic SER -6.0 D or worse, and among 3607 eyes with non-cycloplegic SER -0.5 D or worse (e.g., met myopia definition), 62.1% eyes had cycloplegic SER -0.5 D or worse. Cycloplegic SER was more correlated with axial length than non-cycloplegic SER (Pearson r = 0.82 vs. 0.72, p < .0001). In multivariable analysis, larger SER differences were associated with more hyperopic refractive error and smaller axial length (all p < .0001).

CONCLUSION

Non-cycloplegic refractive error overestimates myopia by approximately one diopter. This overestimation increases with more hyperopic refractive error and smaller axial length. Non-cycloplegic refractive error should not be used for evaluating pediatric myopia.

ABBREVIATIONS

BCVA = best corrected visual acuity; D = diopter; SD = standard deviation; SE = standard error; SER = spherical equivalent; CI = confidence interval.

[Analysis of 39 children with acute necrotizing encephalopathy]

Objective: To investigate the risk factors for death in children with acute necrotizing encephalopathy (ANE) in pediatric intensive care unit (PICU). Methods: This was a multicenter retrospective study. Thirty-nine children with ANE were from PICUs in 4 centers from December 1, 2014 to December 1, 2020. The 4 participating centers were Beijing Children's Hospital, Shengjing Hospital of China Medical University, Hebei Children's Hospital, and Bao'an Maternity & Child Health Hospital. Patients were divided into survival and non-survival groups by the outcome at discharge, and the differences in clinical data between the two groups were compared. Risk factors for death in children with ANE and the odds ratios (OR) were analyzed by univariable Logistic regression. Results: Thirty-nine children with ANE were included. There were 18 males and 21 females. The median onset age was 30 months. The mortality at discharge was 41% (16/39). The onset age of most patients (74%, 29/39) was younger than 4 years old. Influenza virus was the most common precursor infection (80%, 20/25). Patients with shock at PICU admission were more common in the non-survival group (12/16 vs. 17% (4/23), P=0.001). Glasgow coma score (GCS) at PICU admission was significantly lower in the non-survival group than survival group (3 (3, 6) vs. 6 (5, 7), Z=-2.598, P=0.009). The optimal cut-off value was 4. The proportion of patients with GCS ≤ 4 at PICU admission was higher in the non-survival group (10/16 vs. 22% (5/23), P=0.018). ANE severity score (ANE-SS) at PICU admission was significantly higher in the non-survival group (5 (2, 6) vs. 2 (1, 4), Z=-2.436, P=0.015). The proportion of patients with high risk ANE-SS was higher in non-survival group than the survival group (9/16 vs. 22% (5/23), P=0.043). The proportion of application of high-dose methylprednisolone (20 mg/(kg·d)) was significantly higher in survival group than non-survival group (43% (10/23) vs. 1/13, P=0.031). Univariable Logistic regression indicated that risk factors for death in children with ANE were shock (OR=14.250, 95%CI 2.985-68.018, P=0.001), GCS≤4 (OR=6.000, 95%CI 1.456-24.733, P=0.013) and high risk ANE-SS (OR=4.629, 95%CI 1.142-18.752, P=0.032) at PICU admission. Conclusions: ANE usually occurs in children under 4 years old after influenza infection. Shock, GCS≤4 and high risk ANE-SS at PICU admission were risk factors for death in children with ANE. High-dose methylprednisolone may improve the prognosis of children with ANE.

Predictive Value of Clinician "Gestalt" in Pediatric Community-Acquired Pneumonia

OBJECTIVES

Validated prognostic tools for pediatric community-acquired pneumonia (CAP) do not exist. Thus, clinicians rely on "gestalt" in management decisions for children with CAP. We sought to determine the ability of clinician gestalt to predict severe outcomes.

METHODS

We performed a prospective cohort study of children 3 months to 18 years old presenting to a pediatric emergency department (ED) with lower respiratory infection and receiving a chest radiograph for suspected CAP from 2013 to 2017. Clinicians reported the probability that the patient would develop severe complications of CAP (defined as respiratory failure, empyema or effusion, lung abscess or necrosis, metastatic infection, sepsis or septic shock, or death). The primary outcome was development of severe complications.

RESULTS

Of 634 children, 37 (5.8%) developed severe complications. Of children developing severe complications after the ED visit, 62.1% were predicted as having <10% risk by the ED clinician. Sensitivity was >90% at the <1% predicted risk threshold, whereas specificity was >90% at the 10% risk threshold. Gestalt performance was poor in the low-intermediate predicted risk category (1%-10%). Clinicians had only fair ability to discriminate children developing complications from those who did not (area under the receiver operator characteristic curve 0.747), with worse performance from less experienced clinicians (area under the receiver operator characteristic curve 0.693).

CONCLUSIONS

Clinicians have only fair ability to discriminate children with CAP who develop severe complications from those who do not. Clinician gestalt performs best at very low or higher predicted risk thresholds, yet many children fall in the low-moderate predicted risk range in which clinician gestalt is limited. Evidence-based prognostic tools likely can improve on clinician gestalt, particularly when risk is low-moderate.

[Determination of n-butyl alcohol in urine by headspace solid-phase microextraction coupled with gas chromatography]

Objective: To establish a headspace solid phase microextraction-gas chromatography method for determination of n-Butyl alcohol in urine. Methods: In October 2019, the n-butyl alcohol in urine was extracted with a polydimethylsiloxane/divinylbenzene (PDMS/DVB) solid-phase microextraction head. The conditions of salt amount, extraction temperature, extraction time and desorption time were optimized. The separation was performed on HP-5 (30 m×0.32 mm×0.25 μm) capillary column and detected with flame ionization detector. The quantification was based on the external standard curve. Results: The linear relationship of n-butyl alcohol in urine was good in the range of 0.04-3.00 mg/L, the correlation coefficient was 0.999, the detection limit of the method was 0.04 mg/L, the recovery was 77.4%-102.8%, the intra-run precision was 3.67%-8.11%, and the inter-assay precision was 4.94%-6.90%. Conclusion: The method has simple operation, high concentration efficiency and high sensitivity, and it is suitable for the determination of n-butyl alcohol in urine of occupational exposure to n-butyl alcohol.

[A comparative study of four cross-sectional investigations on the status of pediatric intensive care unit in China over the past 30 years]

Objective: To understand the history, current situation and trends of intensive care unit (ICU) of pediatrics in China over the past 30 years. Methods: The results of the cross-sectional investigation on the status of ICU of pediatrics in 2014 were compared with those in 1993, 2001 and 2009. The main measurements were the number of participated provinces and hospitals, the availability of equipment, staffing, and medical technologies, the major diseases and the source of the patients. Besides, the equipment allocation and technology implementation in 2014 were compared with the standards in the "recommendations on grading construction and management of children's intensive care unit in China" published in 2016. Results: The contents of the four surveys were slightly different, with only a few measurements not documented in one or more surveys. (1) The number of provinces and hospitals involved in the four surveys were 20 hospitals in 14 provinces in year 1993, 27 hospitals in 17 provinces in year 2001, 33 hospitals in 25 provinces in year 2009 and 108 hospitals in 25 provinces in year 2014. (2) In 1993, 2001, 2009 and 2014, the ratio of doctors/beds were 0.7∶1,0.8∶1, (0.4-0.5) ∶1 and 0.5∶1, and the ratio of nurses/beds were 1.1∶1,1.4∶1, (1.1-1.7) ∶1 and 1.3∶1, respectively. (3) Regarding the equipment availability, in 1993, 2001, 2009, and 2014, the numbers of monitors were 0.3/ICU, 0.3/bed, 1.1-1.4/bed and 1.0/bed; the numbers of invasive ventilators were 0.4/bed, 0.5/bed, 0.6/bed and 0.4/bed, respectively. In 2001, 2009 and 2014, there were 60.0%, 100.0% (33/33) and 88.0% (95/108) of the participating ICU equipped with blood gas analyzer, and 70.0%, 93.9% (31/33) and 90.7% (98/108) with bedside X-ray machines, respectively. In 2009 and 2014, 69.7% (23/33) and 92.6% (100/108) ICU were equipped with non-invasive ventilators respectively. In 2014, 10.2% (11/108) ICU were equipped with extracorporeal membrane oxygenation (ECMO) equipment and 45.4% (49/108) ICU with bedside continuous blood purification equipment. In 1993, 2001 and 2014, the numbers of infusion pump were 0.5/ICU, 1.1/bed and 1.7/bed, respectively. (4) Regarding the conducted medical technology, in 2014, invasive mechanical ventilation was used in 100% (108/108) ICU, and non-invasive ventilation in 89.8% (97/108) ICU. High frequency ventilation was used in 78.8% (26/33) and 38.0% (41/108) ICU in 2009 and 2014 respectively. Blood purification was used in 22.0%, 69.7% (23/33) and 47.2% (51/108) ICU, and the application of surfactant was in 48.0%, 97.0% (32/33) and 24.1% (26/108) ICU in 2001, 2009 and 2014, respectively. Nitric oxide inhalation (iNO) was used in 24.0% and 9.3% (10/108) in 2001 and 2014 respectively. ECMO was used in 6 and 7 hospitals in 2009 and 2014 respectively. (5) Compared with the criteria in the "recommendations on grading construction and management of children's intensive care units in China" in 2016, only the availability of monitors and conventional mechanical ventilation in 2014 met the standards.The original data in 2001 was not shown due to the lack of absolute values. Conclusions: The number of ICU of pediatrics and its beds in China increased significantly from 1993 to 2014, as well as the equipment availability and the conducted medical technology. But the status in 2014 was still far behind the recommendations in 2016, with a significant shortage of professional staff.

[Effectiveness and safety of nimodipine in preventing cerebral vasospasm after subarachnoid hemorrhage in children]

Objective: To evaluate the effect of prophylactic nimodipine in vasospasm prevention and outcome improvement in children with subarachnoid hemorrhage (SAH). Methods: A prospective, randomized controlled clinical trial which enrolled children with SAH who were admitted to pediatric intensive care unit (PICU) of Beijing Children's Hospital from January 2015 to October 2018 was conducted. A total of 43 patients were randomly divided into nimodipine group (24 patients) and control group (19 patients) according to random number table. Transcranial Doppler (TCD) was used to dynamically monitor blood flow velocity and spectrum monography of bilateral middle cerebral artery (MCA) for vasospasm evaluation. Pediatric cerebral performance category (PCPC) scale was used to evaluate patients' brain function on 28(th) day after discharge. Data were analyzed by t test, Mann-Whitney U test, χ(2) test. Results: Except heart rate ((157±26) vs. (137±34) beats/min, t=2.079, P=0.045), no significant differences existed between the two groups in basic demographic characteristics, primary diseases, and clinical manifestations (all P>0.05). The peak velocities of bilateral MCA on the 5(th) day after admission were significantly lower in nimodipine group (left MCA (136±34) vs. (158±23) cm/s, t=-2.890, P=0.006; right MCA (129±34) vs. (176±27) cm/s, t=-3.717, P=0.001). Likewise, a lower peak velocity of left MCA was observed on the 7(th) day after admission in nimodipine group ((127±45) vs. (152±13) cm/s, t=-2.903, P=0.007), but no significant difference existed in that of right MCA ((131±48) vs. (150±22) cm/s, t=-1.760, P=0.090). Eleven patients suffered from vasospasm, 25% (6/24) in nimodipine group and 26% (5/19) in control group (χ(2)=0.010, P=1.000), within whom 8 patients had complete remission after continuing nimodipine treatment, one died in hospital and the other two's vasospasm still existed at the time of discharge. No significant differences were found between the two groups in mean length of hospitalization, proportion of mechanical ventilation, Glasgow coma scale at discharge, survival rate at discharge or survival rate on 28(t)h day after discharge (all P>0.05). However, nimodipine group had a higher proportion of favorable PCPC brain function (92% (22/24) vs. 63% (12/19), χ(2)=5.208, P=0.030). No side effects such as hypotension, rash or injection site erythema were observed. Conclusion: Prophylactic nimodipine cannot reduce vasospasm incidence in children with SAH but may improve short-term brain function, without any significant safety issues.

Application of Multiple Kits in Special Parentage Testing Cases

OBJECTIVES

To analyse the genetic polymorphism of 21 autosome STR loci in Han population of Shandong Province and the cases with loci mutation or allelic loss typed by Goldeneye® DNA identification system 25A.

METHODS

Totally 40 autosome STR loci types of 273 unrelated individuals in Han population of Shandong Province were typed by Goldeneye® DNA identification system 25A and 22NC, and the genetic polymorphism of 21 STR loci in those was analysed. Meanwhile, six cases with loci mutation were analysed by adding the tests with Goldeneye® DNA identification system 22NC, 20Y and 17X. Another three cases with allelic loss were tested by AmpFℓSTR® Identifiler® Plus PCR and analysed by gene sequencing.

RESULTS

The genetic parameters of 21 autosome STR loci in Han population of Shandong Province were obtained. When STR loci were added up to 40, five of those with loci mutation met the identification requirements, and the results of X-STR or Y-STR types were consistent with that of STR loci. There was another duo case with one suspected loci mutation, biological source of six STR loci genotypes could not be found in the genotypes of supposed father. The Y-STR genotype of two individuals was identical that indicated both of them came from same paternal line. However, the fatherhood was excluded according to the autosome STR loci system. For two cases with allelic loss on D18S51, base mutation or loss were found in the primer binding domain of mother and child by gene sequencing. Another mother-child case with allelic loss on D13S317 was certified by AmpFℓSTR® Identifiler® Plus PCR kit.

CONCLUSIONS

The 21 autosome STR loci in Han population of Shandong Province have high polymorphism, which can be used in routine cases of paternity identification. For some duo cases with loci mutation, Goldeneye® DNA identification system 25A cannot satisfy the identification requirements, thus more autosome STR loci should be added properly. For the cases with allelic loss, the problem can be resolved by gene sequencing or using different merchant kits.

Investigation on the optimized algorithm for electrostatic tomography

Particle charging in gas-solid two-phase flow is an important concern in many industrial processes. The technique of electrostatic tomography (EST) based on particle charging can achieve flow regime identification and infer concentration and flow rate by detecting the charged particles. Successful application of EST depends on the sensitivity map and the image reconstruction algorithm. In this paper, the effects of the sensitivity map on EST were demonstrated and a novel sensitivity map was presented. Then, optimized Tikhonov iterative algorithm (ITIK) was proposed to improve the quality of EST. The simulated results illustrate that the novel sensitivity map improves the quality of the reconstructed image of EST and the optimized ITIK has better performance in reconstructing the image of EST when compared with linearized back-projection algorithm, iterative linearized back-projection algorithm, and ITIK. Finally, the experimental studies were conducted and the simulated results were validated. The results indicate that the novel sensitivity map and the optimized algorithm can enable good applications of EST in gas-solid two-phase flow measurement.

[Genetic Polymorphisms of 19 STR Loci in Populations of Three Culture Region in Shandong]

OBJECTIVES

To analyse the genetic polymorphisms of 19 autosomal STR loci in Han population of east, middle-northwest and southwest-south Shandong and to explore its genetic relationships among the population of these three regions.

METHODS

STR loci of 1 044 unrelated Han individuals in three Shandong regions were typed with a Goldeneye® DNA ID System 20A kit. The allele frequency and population genetics parameters of 19 autosomal STR loci were statistically analysed by Modified-Powerstates software. The genetic distances among the population in three regions were calculated by Arlequin v3.5 software. The phylogenetic tree was conducted using MEGA v4.0 software.

RESULTS

Fifteen of 19 autosomal STR loci were detected with the H values greater than 0.7, PIC values greater than 0.7, and DP values greater than 0.9 in the populations of all three Shandong regions. Among the populations in these three regions, the genetic distance between the populations in middle-northwest and southwest-south Shandong was closest （F_st=0.000 16）, followed by east and southwest-south Shandong （F_st=0.0003 6）. The genetic distance between the populations in east and middle-northwest Shandong was the farthest （F_st=0.000 66, P<0.05）.

CONCLUSIONS

The 19 autosomal STR loci show good genetic polymorphisms in Han population of three Shandong regions, and 15 of them are high. There are genetic differences between the populations in east and middle-northwest Shandong.

Analysis of the 19 Y-STR and 16 X-STR loci system in the Han population of Shandong province, China

The sex-linked short tandem repeats (STR), Y-STR and X-STR, are important for autosomal STRs in forensic paternity testing. We evaluated the forensic parameters of 19 Y-STRs and 16 X-STRs in the Han population of Shandong province, China. A Goldeneye 20Y kit (DYS391, DYS389I, DYS390, DYS389II, DYS348, DYS456, Y-GATA-H4, DYS447, DYS19, DYS392, DYS393, DYS388, DYS439, DYS635, DYS448, DYS460, DYS458, DYS437, DYS385 a/b) was used to analyze the forensic parameters of 534 unrelated males. A Goldeneye17X system (DXS6795, DXS9902, DXS8378, HPRTB, GATA165B12, DXS7132, DXS7424, DXS6807, DXS6803, GATA172D05, DXS6800, DXS10134, GATA31E08, DXS10159, DXS6789, DXS6810, amelogenin) was used to analyze 97 unrelated males and 214 females. In addition, we used the kits to examine 5 cases with abnormal amelogenin test results, as well as a male child with agenosomia typed by autosomal STR. We found 203 Y-STR haplotypes with allele frequencies ranging from 0.0019 to 0.7959, and GD ranging from 0.3429 to 0.9667. Expect in DXS6803, the allele frequencies of the other 15 X-STR loci showed no differences between females and males. PD_F ranged from 0.5504 to 0.9638, while PD_M ranged from 0.3176 to 0.8377. With the exception of DXS6803 and DXS6810, the allele frequencies of other X-STR loci were in accordance with Hardy-Weinberg equilibrium in females. One amelogenin negative case was characterized as a deletion of Y-DYS458. This paper provided data regarding the genetic polymorphism of Y-STRs and X-STRs in the Han population, and demonstrated the importance of Y-STR and X-STR in forensic autosomal STR analysis.

Molecular consequences of activated microglia in the brain: overactivation induces apoptosis

Microglia, the resident immune cells in the brain, play a pivotal role in immune surveillance, host defense, and tissue repair in the CNS. In response to immunological challenges, microglia readily become activated as characterized by morphological changes, expression of surface antigens, and production of immune modulators that impact on neurons to induce neurodegeneration. However, little is known concerning the fate of activated microglia. In the present study, stimulation of cultured rat primary microglia with 1 ng/mL of the inflammagen lipopolysaccharide (LPS) resulted in a maximal activation as measured by the release of tumor necrosis factor alpha (TNF alpha). However, treatment with higher concentrations of LPS resulted in significantly lower quantities of detectable TNF alpha. Further analysis revealed that overactivation of microglia with higher concentrations of LPS (> 1 ng/mL) resulted in a time- and dose-dependent apoptotic death of microglia as defined by DNA strand breaks, surface expression of apoptosis-specific markers (phosphatidylserine), and activation of caspase-3. In contrast, astrocytes were insensitive to LPS-induced cytotoxicity. In light of the importance of microglia and the limited replenishment mechanism, depletion of microglia from the brain may severely hamper its capacity for combating inflammatory challenges and tissue repair. Furthermore, overactivation-induced apoptosis of microglia may be a fundamental self-regulatory mechanism devised to limit bystander killing of vulnerable neurons.

[Automatic analyzing system for human chromosome]

A designing method for chromosome automatic analyzing system is presented in the paper. The system accomplishes chromosome automatic recognizing, sorting, pairing, picking out aberrant chromosomes and then makes diseases-diagnosis.

Origin and evolutionary characteristics of antigenic reassortant influenza A (H1N2) viruses isolated from man in China

During the 1988/1989 influenza season, five antigenic reassortant influenza A (H1N2) viruses not previously isolated from man were isolated in Hebei province, People's Republic of China. All isolates contained haemagglutinins (HAs) and neuraminidases (NAs) which were antigenically similar to those of the recent Russian (H1N1) and Hong Kong influenza A (H3N2) viruses, respectively. The results of antigenic and nucleotide sequence analyses revealed that the genes encoding the polymerase, nucleoprotein, NA, matrix and non-structural proteins of the reassortant A/Hebei/24/89 (H1N2) virus were derived from the H3N2 parent virus, whereas its HA gene was from the H1N1 parent virus. The nucleotide sequences of the HA (encoding the HA1 subunit) and NA genes of the reassortant viruses were also determined. Phylogenetic trees constructed from these data by the neighbour-joining method revealed that the HA gene of the reassortant virus was closely related to those of recent human H1N1 viruses, whereas the NA gene was related to a recent human Hong Kong (H3N2) virus lineage.