Objective:To study the clinical features and treatment strategy of neonatal ureaplasma meningitis.Methods:During 2021, the clinical data of 2 neonates with ureaplasma meningitis treated in Children's Hospital of Hunan Province were retrospectively analyzed. Literature on this subject were searched in the following databases: CNKI, Wanfang Database, Chinese Medical Journal Full-Text Database, CQVIP database, SinoMed, PubMed, Embase and Web of Science (up to March 2022). The key words included “infant”, “neonate”, “newborn”, “ureaplasma”, “mycoplasma urealytium”, “meningitis”, “central nervous system infection”, “brain”. The clinical data, treatment and prognosis of patients from the literature were summarized.Results:Case 1, female, gestational age(GA) 33 +3 weeks, intracranial hemorrhage (ICH) and ventricular dilatation were found on 2 d after birth. The cerebrospinal fluid (CSF) routine and biochemistry tests indicated meningitis, but the CSF culture was negative. No improvement after antibiotic treatment. CSF metagenomic next-generation sequencing (mNGS) and 23S rRNA showed Ureaplasma urealyticum on 30 d after birth. The patient was treated with doxycycline (DOX) for 21 d until mNGS turned negative and DOX was discontinued. However, the disease recurred 23 d later and erythromycin was added with DOX as combined therapy. The patient was followed up until 6 months without neurodevelopmental disabilities. Case 2, male, GA 26 weeks, ICH and ventricular dilatation were found on 10 d after birth. The CSF routine and biochemistry tests indicated meningitis, but the CSF culture was negative. No improvement after antibiotic treatment. CSF mNGS and 23S rRNA showed Ureaplasma parvum. The patient received erythromycin therapy for 32 d and had normal neurodevelopment at 5 months. According to the literature, 43 cases were reported including the 2 cases descirbed above, 17 cases were full-term infants and 26 cases were preterm infants. The median CSF leukocytes, glucose and proteins were 566 cells/mm 3, 0.2 mmol/L and 2.2 g/L. 27 cases were diagnosed based on CSF culture, 6 cases using mNGS, 4 cases with both CSF culture and PCR method and 6 cases with other methods. Macrolides alone were used in 14 cases, macrolides combined with another antibiotic were used in 8 cases, non-macrolide antibiotics were used in 9 cases and 12 cases didn't receive any anti-ureaplasma therapy. All 17 term infants survived, however, 8 cases with hydrocephalus. Among the 26 preterm infants, 8 patients died, 18 patients had periventricular-intraventricular hemorrhage and 15 patients had hydrocephalus. Conclusions:Neonatal ureaplasma meningitis has significantly lower CSF glucose level with hydrocephalus as the common complication. For intracranial infections of unknown etiology and no response to treatment, mNGS is helpful in determining the pathogen.Neonatal ureaplasma meningitis should be treated with macrolides alone or as add-on therapy.

Objective:To evaluate the impacts of tissue heterogeneity on dose calculation of cervical brachytherapy by comparing the doses calculated by two clinically used dose calculation method and the CT image-based Monte Carlo (MC) method.Methods:This study retrospectively selected 11 patients with cervical cancer treated with 3D brachytherapy in Anhui Provincial Cancer Hospital from January 2018 to June 2020. The dose distribution of each plan was calculated via three methods, dose calculation method described in American Association of Physicist in Medicine(AAPM) Task Group No. 43 Report (TG43-BT), Acuros BV(BV-BT) used to perform accurate dose calculations in high-dose-rate (HDR) brachytherapy with phantom heterogeneity, and CT image-based EGSnrc tool kit used to perform Monte Carlosimulation (MC-BT). The dose volumes( V3 Gy, V6 Gy, V9 Gy, and V12 Gy), target volume doses( D98, D90, D50), D2 cm 3 of organs at risk (OARs) calculated by the three methods were compared. Results:The HRCTV D90obtained by TG43-BT was 6.274 Gy, which was even overestimated by around 5% compared to the result calculated by MC-BT. Meanwhile, TG43-BT overestimated the dose volumesand the target volume doses compared to MC-BT.Except for D50 and V12 Gy, the differences between the doses to tumor calculated by BV-BT and MC-BT were not statistically significant( P>0.05). There was also no significant statistical difference between the D2 cm 3 of rectum, small intestine, and sigmoid calculated by BV-BT and MC-BT ( P>0.05). In contrast, the dose to D2 cm 3 of bladder determined by MC-BT was 4.609 Gy, which was notably higher than those deter mined by TG43-BT and BV-BT. Conclusions:TG43-BT overestimated the doses to tumor targets and most OARs since the effects of tissue heterogeneity were not taken into consideration. BV-BT performed efficient calculation and most of the dose distributionin target volume and OARs obtained by BV-BT were consistent with that calculated by MC-BT. Nevertheless, low accuracy occurred for the regions near the sources and full bladder, which warrants further caution in clinical evaluation.

Objective:To investigate the impacts of the composition and physical density of tissue on the dose distribution of implanted 125I seeds, in order to provide references for the clinical dose calculation and assessment of implanted radioactive particles. Methods:The OncoSeed 6711 physical model of 125I seeds was established using thes of twareegs_brachy and was validated through the calculation of dose rate constant and the radial dose function [ g( r)] in water. Then, based on the element composition and physical density of different types of tissue, the g( r) and absorbed dose ratein water, prostate, breast, muscle, and bone were calculated. Results:The calculated dose rate constant (0.950 cGy·h -1·U -1) and g( r)in water approached the values in related literature. The absorbed dose in bone was 6.042 times than that in water at a distance of 0.05 cm from the implanted source. The difference between the absorbed doses in breast and water was more than 10% at a distance of less than 1.7 cm from the implanted source. The difference between the absorbed doses in prostate/muscle and water was less than 5% at the same radial location. Conclusions:The dose distribution of 125I seeds in some types of human tissue is significantly different from that in water, which should be carefully considered in clinical dose calculation.

Objective:To study the clinical efficacy, safety and prognosis of systemic hypothermia therapy on neonatal hypoxic-ischemic encephalopathy (HIE)initiated at different times after birth.Method:From January 2013 to August 2018, term neonates (within 12 hours after birth) diagnosed with neonatal moderate to severe HIE and received systemic treatment in the neonatal intensive care unit of our hospital were retrospectively included. According to the starting time of hypothermia therapy, the neonates were assigned into three groups: within 6 h after birth (TH1 group), 6~12 h (TH2 group) and conventional treatment group (control group). Their clinical data during perinatal period, hospitalization period and follow-up at 6-month were reviewed. Their clinical and neurodevelopmental outcomes were compared using SPSS 25.0 statistical software.Result:A total of 147 neonates with moderate to severe HIE were enrolled. 111 received 72-hour hypothermia therapy, including 79 in the TH1 group, 32 in the TH2 group and 36 in the control group. The neurobehavioral test scores at 10-day of life in the TH1 group were significantly higher than the control group ( P<0.05). No significant differences existed among the TH2 group, the TH1 group and the control group ( P>0.05). The brain magnetic resonance imaging (MRI) showed injuries in the TH1 group and the TH2 group were significantly milder than the control group ( P<0.05). No significant differences of brain injuries existed between TH1 group and TH2 group ( P>0.05). 100 patients completed Bailey Infant Intelligence Development Scale at 6-month follow-up. 21 had abnormal scores. No statistically significant differences existed in the psychomotor development index (PDI) scores among the three groups ( P>0.05). TH1 and TH2 groups had significantly fewer cases with mental development index (MDI) <70 points than the control group ( P<0.05). No statistically significant differences existed of MDI scores between the TH1 group and the TH2 group ( P>0.05). No statistically significant differences existed of PDI scores among the 3 groups ( P>0.05). At 6-month, the mortality rate of the control group (32.1%, 9/28) was significantly higher than the TH1 group (6.6%, 4/61) ( P<0.05). No significant differences existed of mortality rate at 6-month among the TH2 group, the TH1 group and the control group ( P>0.05). Conclusion:Systemic hypothermia therapy for neonatal HIE is safe. Starting systemic hypothermia therapy at 6~12-hour after birth may also be effective in reducing mortality rate and improving neurodevelopmental outcome.

Objective:To investigate the dosimetry differences in the treatment of locally advanced cervical cancer with intracavitary/interstitial brachytherapy (IC/IS BT), intracavity brachytherapy combined with intensity modulated radiotherapy (ICBT+ IMRT) and simple IMRT.Methods:Totally 16 patients with local advanced cervical cancer were retrospectively selected, which were treated by three-dimensional brachytherapy. On the basis of the original three-dimensional intracavitary/interstitial brachytherapy plan, ICBT+ IMRT and IMRT plans were designed respectively to study the dosimetry differences of target and different organs at risk for the three kinds of plans.Results:A total of 75 brachytherapy treatment plans were designed, including 25 IC/IS BT, 25 ICBT+ IMRT and 25 IMRT. There was not statistically significant difference of target dose parameters between ICBT+ IMRT and IC/IS BT plan ( P>0.05). ICBT+ IMRT plans had better OAR sparing than IC/IS BT. The doses of OARs in the IMRT plans were relatively large and the volume irradiated to more than 60 Gy ( V60) was significantly higher( t=6.77, 10.37, 4.61, 2.83, P<0.05). Conclusions:The ICBT+ IMRT technique not only provides better target coverage, but also maintains low doses to the OARS, which can be used as an alternative treatment to IC/IS BT. Although the target coverage of IMRT is better, the protection of OARs is not satisfied, so it is not suitable for local boost therapy of advanced cervical cancer.

Due to low autoimmune function, imperfect development of various organs, coupled with a variety of invasive operations and other factors, premature infants are high-risk groups of invasive fungal infection.Invasive candida infection in premature infants accounts for more than 80% of invasive fungal infection. The main infection rate of invasive candida albicans was candida albicans. However, in recent years, the infection rate of non-candida albicans such as candida albicans, tropical candida, smooth candida and other non-candida albicans showed a gradual upward trend.In addition to blood culture, the latest diagnostic methods such as plasma (1-3)-β-D-glucan test and candida polymerase chain reaction are helpful for the diagnosis of invasive fungal infection. At the same time, attention should also be paid to prophylactic antifungal therapy and empirical antifungal therapy in premature infants.

High mobility group box 1 protein(HMGB1) is widely present in eukaryotic nuclei and named for its rapid migration during polyacrylamide gel electrophoresis. Studies have shown that HMGB1 playes an important role in the development of gene transcription,inflammation,cancer and other diseases. In this paper, the biological characteristics of HMGB1 and its research progress in pediatric diseases are reviewed.

Objective To study the transport risk and factors that influence deaths of very low birth weight (VLBW) and extremely low birth weight (ELBW) infants.Method All infants transferred to our neonatal intensive care unit (NICU) by our hospital transport team or local hospital transport team from January 2014 to December 2015 were included in our study.Their clinical data were retrospectively studied.The risks of transport between hospitals were analyzed.The risk factors of deaths within and after 7 days of admission were further analyzed by multivariate Logistic regression analysis.The receiver operation characteristic (ROC) curve was used to assess the sensitivity and specificity of mortality index for neonatal transportation (MINT),transport related mortality score (TREMS),transport risk index of physiologic stability (TRIPS) for predicting mortality of preterm infants.Result (1) A total of 527 cases of ELBW/VLBW infants were included in our study.There were no deaths during transport.There were 10.2％ (54/527) died within and 8.9％ (42/473) died after 7 days of hospitalization.(2) Multivariate Logistic regression analysis showed that scleredema of newborn,secondary transport,gastrointestinal malformations,metabolic acidosis,high TREMS score,and high MINT score were risk factors of mortality within 7 days of admission for ELBW/VLBW infants;necrotizing enterocolitis,intraventricular hemorrhage ≥ three degree,high MINT score and low admission weight were risk factors of mortality after 7 days of admission.(3) The area under the ROC curve for MINT,TREMS,and TRIPS score were 0.672,0.655 and 0.665,respectively.The cut-off values for MINT score (cut-off 8,sensitivity 0.444,specificity 0.829),for TREMS score (cut-off 2,sensitivity 0.500,specificity 0.757,for TRIPS score (cut-off 20,sensitivity 0.444,specificity O.829) were selected to predict mortality within 7 days of admission.Conclusion (1) Secondary transport is the transport-related risk factor of mortality within 7 days of admission for ELBW/VLBW infants.(2) High MINT score is the risk factor of mortality within and after 7 days of admission.(3) If MINT ≥ 8,TREMS ≥2,or TRIPS ≥20,it might significantly increase the risk of mortality of ELBW/ VLBW infants within 7 days of admission after transport.

Objective To study the occurrence of bronchopulmonary dysplasia (BPD) in extremely low birth weight (ELBW) infants and to determine the risk factors of severe BPD.Method From January 2007 to January 2017,ELBW infants admitted to neonatal intensive care unit (NICU) in Hunan Children's Hospital were retrospectively analyzed.They were assigned into severe and mild/moderate groups based on the severity of BPD.The general condition,maternal status,prenatal and delivery room treatment,transportation,clinical courses,therapy and outcome in NICU of the two groups were compared,and the risk factors of severe BPD were analyzed.Result A total of 367 cases were hospitalized during the 10 years.281 ELBW infants with complete medical records survived longer than 28 days were enrolled in this study.Among them,233 had BPD.Among BPD infants,116 cases were in the severe BPD group,47 cases (40.5％) died.117 cases were in the mild/moderate BPD group and 1 case (0.9％) died.The difference between the two groups was statistically significant (P ＜ 0.05).Multivariate Logistic regression analysis showed that the risk factors of severe BPD were duration of mechanical ventilation ≥ 7 days (OR =7.518,95 ％ CI 3.197 ～ 17.676),ventilator-associated pneumonia (OR =3.047,95 ％ CI 1.436 ～ 6.464),1 min Apgar score ≤7 (OR =2.341,95 ％ CI 1.142 ～ 4.796) and patent ductus arteriosus (OR =2.223,95 ％ CI 1.079 ～4.582).Conclusion The incidence and mortality of BPD,especially severe BPD,are high in ELBW infants.Avoiding asphyxia,shortening the time of mechanical ventilation,preventing infection and closing ductus arteriosus are important measures to reduce the severity of BPD.

Objective To study the dosimetric parameters of Varian GammaMed Plus HDR 192 Ir source via Monte Carlo ( MC ) method based on the recommendation of the American Association of Physicist in Medicine ( AAPM) and European Society for Radiotherapy and Oncology ( ESTRO) . Methods Using the Monte Carlo program EGSnrc, an accurate model of 192 Ir source for MC calculations was establish firstly. Through formula derivation, bilinear interpolation and unit conversion, the air kerma strength per unit source activity, the dose rate constant, radial dose function and anisotropy function was obtained then , and compare the result with those in other published studies. Results The air kerma strength per unit source activity was 9. 781 × 10-8 U/Bq. The dose rate constant was 1. 113 cGy · h-1 · U-1 , with a discrepancy of less than 0. 4％ compared with result published in other works. Furthermore, the curves of radial dose function and anisotropy function overall agree with the data shown in the literature. Conclusions The feasibility of performing dosimetric studies of 192 Ir source using the MC software EGSnrc was demonstrated. This work provides a theoretical guidance on analysis of the dose distribution of brachytherapy and on evaluation of the dose accuracy of clinical radiotherapy.