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Objective:To explore the effects of prenatal dexamethasone (DEX), postnatal pulmonary surfactant (PS) and respiratory support on the lung fluid clearance in premature rabbits at gestational age (GA) of 25-28 d (full term: 31 d) and their relationship with dynamic compliance of respiratory system (Cdyn), pulmonary morphology and other parameters.Methods:In our previous publications, premature rabbits were divided into four groups according to the intervention strategy: control group, PS-only group, DEX-only group and DEX+PS group in which data of several parameters including wet-to-dry lung weight ratio (W/D), Cdyn and volume density of alveoli (Vv) were retrieved and the lung tissue sections were scanned to recalculate the ratio of perivascular sheath to vascular sectional area (S/V) and lung injury scores-edema (LIS-E). W/D, LIS-E, S/V and Vv were adjusted for birth weight (BW) (divided by BW, represented as W/D/BW, LIS-E/BW, S/V/BW and Vv/BW) and mean Cdyn (Cdyn-m) was adopted. Based on the grouping of previous studies, the intervention groups in this study were divided as DEX group and non-DEX group, and PS group and non-PS group to analyze the influence of DEX and PS on the above parameters. Two independent samples t-test, one-way analysis of variance, LSD test, Kruskal-Wallis H test, Mann-Whitney U test and Pearson correlation analysis were used for statistical analysis. Results:A total of 196 newborn rabbits receiving mechanical ventilation after birth were included in this study. (1) Effects of DEX: compared with the non-DEX group, the DEX group showed increased W/D/BW (489±69 vs 421±113, t=－2.09), LIS-E/BW (188±57 vs 138±55, t=－2.61) and Vv/BW (20.1±4.9 vs 14.2±4.7, t=－3.60), but decreased S/V (0.33±0.23 vs 0.51±0.25, t=2.23) and S/V/W/D (0.05±0.03 vs 0.07±0.04, t=2.22) at 25 d of gestation; at 26 d of gestation, W/D/BW (472±76 vs 303±44, t=－8.75), LIS-E/BW (189±63 vs 106±36, t=－5.23), Cdyn-m [(0.16±0.07) vs (0.05±0.03) ml/(kg?cmH 2O), 1 cmH 2O=0.098 kPa; t=－7.29] and Vv/BW increased (22.4±5.0 vs 12.2±3.8, t=－7.46), while S/V (0.23±0.19 vs 0.62±0.38, t=4.10), S/V/BW (15.7±12.4 vs 25.7±17.3, t=2.20), S/V/W/D (0.03±0.03 vs 0.08±0.05, t=3.92) and propensity scores decreased [(12.5±1.2) vs (15.1±1.2) scores, t=7.00]; at 27 d of gestation, Cdyn-m increased [(0.23±0.12) vs (0.16±0.07) ml/(kg?cmH 2O), t=－2.43], but S/V (0.32±0.23 vs 0.57±0.39, t=2.57) and S/V/W/D decreased (0.05±0.04 vs 0.09±0.06, t=2.55); at 28 d of gestation, W/D/BW (270±64 vs 162±33, t=－8.09), LIS-E/BW (72±32 vs 35±20, t=－5.17), S/V (0.90±0.60 vs 0.59±0.48, t=－2.81), S/V/BW (34.0±23.6 vs 15.2±12.7, t=－3.77) and Vv/BW increased (16.9±4.3 vs 9.2±2.9, t=－8.04); the differences were all statistically significant (all P<0.05). (2) Effects of PS: compared with the non-PS group, the PS group had decreased LIS-E/BW at 25, 26 and 27 d of gestation, increased Cdyn-m and Vv/BW at 25 and 27 d of gestation and higher propensity scores at 25 d of gestation (all P<0.05). (3) The correlation between gestational age and each index: gestational age was positively correlated with S/V ( r=0.31, P<0.05), but negatively correlated with W/D/BW and LIS-E/BW ( r=－0.73 and－0.63, both P<0.05). Conclusions:The pharmacological action of prenatal DEX on lung fluid clearance is mainly confined to preterm rabbits at the GA of 28 d which is supported by mechanical ventilation. Prenatal treatment with DEX and/or postnatal PS can improve the early respiratory function in preterm rabbits between GA of 25-27 d, but had no substantial impact on lung fluid clearance. The GA-related lung maturation appears to play a crucial role, in comparison with medications, in lung fluid clearance.
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Objective@#To investigate the clinicopathological manifestations, molecular genetic, diagnostic histology and differential diagnosis of alveolar soft part sarcoma (ASPS) in children.@*Methods@#A total of 13 cases of ASPS diagnosed at Beijing Children′s Hospital from August 2009 to November 2018 were collected. HE staining, histochemical staining for PAS and D-PAS, immunohistochemical (IHC) staining for TFE3, INI1 and CD68 and florescence in situ hybridization (FISH) for TFE3 gene translocation were performed.@*Results@#There were four males and nine females, age ranged from 1 year and 2 months to 13 years and 8 months (mean 7.8 years); and four patients were under 5 years old. Histologically, the tumors showed a distinctive and characteristic nested or organoid growth pattern (11 cases) or solid, diffuse growth (2 cases). The tumor cells possessed abundant eosinophilic, or glycogen-rich and clear to vacuolated cytoplasm. The chromatin was relatively dispersed, with prominent and pleomorphic nucleoli; mitotic figures were rare. Vascular invasion was frequently seen. IHC staining showed specific nuclear TFE3 staining. The tumor cells were also positive for INI1,CD68 and vimentin; but were negative for MyoD1, Myogenin, CK and S-100 protein. Seven cases showed PAS and D-PAS staining, with fuchsia acicular or rod-shaped crystals in tumor cytoplasm. Nine cases showed TFE3 break-apart signals by FISH.@*Conclusions@#ASPS is a rare soft tissue sarcoma in children. Compared with ASPA in adults, it has both similarities and unique clinicopathologic characteristics. The diagnosis needs to be confirmed by combining clinical, pathologic, IHC and genetic testing.
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Objective@#To investigate the epidemiologic features of respiratory viral etiology in hospitalized children with acute respiratory tract infection (ARTI) in Shijiazhuang.@*Methods@#A total of 28 512 cases of hospitalized children with clinical diagnosis of ARTI in Children′ s Hospital of Hebei Province from 2014 to 2017 were recruited into this study. One nasopharyngeal swab was collected from each patient. Immunofluorescence assay was used to detect seven kinds of respiratory viruses, including respiratory syncytial virus (RSV), parainfluenza virus (PIV) type 1-3, influenza virus type A, B (FluA, FluB) and adenovirus (ADV).@*Results@#At least one viral pathogen was identified in each of 9 263 out of 28 512 patients and the overall positive rate was 32.5%. Of 9 263 virus-positive patients, 9 070 (97.9%) had mono-infection. The most frequently detected virus was RSV, followed by PIV-3 and FluA. The positive rates of RSV and PIV-1 showed annually decreasing tendency, meanwhile the positive rate of FluA increased in the nearly two years. The detection rate of ADV and PIV-1 increased every other year. There was a significant difference in the positive rate among different years (P<0.05). The overall positive rate decreased along with the age increased (linear by linear association χ2=1191.289, P<0.05). The detection rates of RSV and PIV-3 were the highest in groups of <1 year old and 1-3 years old and decreased along with the age increased. The preschool children were more susceptible to developing FluA, FluB and ADV related diseases. There was a significant difference in the positive rate among different age groups (P<0.05). The viral distribution was uneven in different seasons, and the infection peaked in winter, the difference was statistically significant (P<0.05). The epidemic seasons of RSV and FluA were winter, and FluB infection was epidemic in winter and spring. The positive rates of PIV-1 and PIV-2 were most common in summer and autumn. PIV-3 was usually prevalent in spring and summer and ADV was prevalent sporadically.@*Conclusions@#RSV is the most common pathogen in hospitalized children with clinical diagnosis of ARTI during 2014-2017 and the positive rate of which showed an annually decreasing tendency. The positive rate of FluA increased in the nearly two years. Children in infancy are susceptible to the seven common respiratory viruses and winter is the epidemic season for these viruses.
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Objective@#To explore the mechanical changes and distributions of pressure in each characteristic intervertebral disc after short segment unilateral pedicle screw fixation in Chinese mini-pigs.@*Methods@#Six characteristic spine segments of 6-week-old Chinese mini-pigs (T3-4、T11-12、T15-L1、L3-4、L4-5 segments with adjacent upper and lower vertebrae) were chosen as experimental models. A biomechanical machine and pressure sensitive film were used to measure the pressure on the vertebral columns when they were subjected to pressures of 200 N as unfixed group. Compression was carried out under vertical, 5 °flexion, 5 °extension and 5 °lateral bending, respectively. Then the PCF (posterior cervical fixation) system were fixed on all segments (left side) as fixed group, and biomechanical tests were repeated to obtain data. A Fujitsu densitometer (Japan) was used to measure the pressure on each direction of the pressure sensitive film.@*Results@#In vertical pressures, 5° flexion and 5°extension conditions, the posterior pressure of T3-4、T11-12、T15-L1、L3-4 and L4-5 intervertebral discs were decreased after fixation, the differences were statistically significant; The fixed side pressures of T3-4、T11-12、T15-L1、L3-4 and L4-5 in the fixed group were significantly lower than those in the unfixed group in the corresponding segments and load conditions, and the differences were statistically significant. The concave disc pressures of T3-4、T11-12、T15-L1、L3-4 and L4-5 in the fixed group were 0.83±0.12, 0.93±0.12, 0.50±0.05, 0.60±0.10 and 0.55±0.08 MPa respectively, which were lower than those of the unfixed group 1.70±0.18, 1.79±0.14, 1.84±0.22, 1.74±0.28, 1.60±0.23 MPa, and the differences were statistically significant. The total disc pressure of the fixed group was significantly lower than that of the non-fixed group in vertical compression, 5 degree flexion and 5 degree extension, and the differences were statistically significant.@*Conclusion@#Unilateral pedicle screw fixation can decrease the pressure on fixed side of fixed group in all conditions and change the distribution of pressure. The posterior pressure decreased particularly. Short- segment unilateral pedicle screw fixation can decrease the average pressure of intervertebral disc, which is an excellent surgery in curing scoliosis in young children.
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Objective To explore the mechanical changes and distributions of pressure in each characteristic interverte?bral disc after short segment unilateral pedicle screw fixation in Chinese mini?pigs. Methods Six characteristic spine segments of 6?week?old Chinese mini?pigs (T3?4、T11?12、T15?L1、L3?4、L4?5 segments with adjacent upper and lower vertebrae) were cho?sen as experimental models. A biomechanical machine and pressure sensitive film were used to measure the pressure on the verte?bral columns when they were subjected to pressures of 200 N as unfixed group. Compression was carried out under vertical, 5°flex?ion, 5°extension and 5°lateral bending, respectively. Then the PCF (posterior cervical fixation) system were fixed on all segments (left side) as fixed group , and biomechanical tests were repeated to obtain data. A Fujitsu densitometer (Japan) was used to mea?sure the pressure on each direction of the pressure sensitive film. Results In vertical pressures, 5°flexion and 5°extension condi?tions,the posterior pressure of T3?4、T11?12、T15?L1、L3?4 and L4?5 intervertebral discs were decreased after fixation,the differ?ences were statistically significant;The fixed side pressures of T3?4、T11?12、T15?L1、L3?4 and L4?5 in the fixed group were signif?icantly lower than those in the unfixed group in the corresponding segments and load conditions, and the differences were statisti?cally significant. The concave disc pressures of T3?4、T11?12、T15?L1、L3?4 and L4?5 in the fixed group were 0.83±0.12, 0.93± 0.12, 0.50±0.05, 0.60±0.10 and 0.55±0.08 MPa respectively, which were lower than those of the unfixed group 1.70±0.18, 1.79± 0.14, 1.84±0.22, 1.74±0.28, 1.60±0.23 MPa, and the differences were statistically significant. The total disc pressure of the fixed group was significantly lower than that of the non?fixed group in vertical compression, 5 degree flexion and 5 degree extension, and the differences were statistically significant. Conclusion Unilateral pedicle screw fixation can decrease the pressure on fixed side of fixed group in all conditions and change the distribution of pressure. The posterior pressure decreased particularly. Short? segment unilateral pedicle screw fixation can decrease the average pressure of intervertebral disc, which is an excellent surgery in curing scoliosis in young children.