Objective:To better understand the clinical characteristics of children with pneumocystis pneumonia(PCP).Methods:Seven cases of non-human immunodeficiency virus infected children with PCP admitted to pediatric intensive care unit(PICU) at Xi′an Children′s Hospital from January 1, 2019 to December 31, 2019 were enrolled.Clinical findings, laboratory examination results, diagnosis, treatment, and outcome data were retrospectively reviewed.Results:There were seven children enrolled in this study including six boys and one girl.The average age was(6.09±3.80)years.Six patients received a long-term steroid or immunosuppressive therapy, and the average duration of medication was(80±30)days.One patient was eventually diagnosed with immunodeficiency disease despite no history of steroid and immunosuppressive therapy.Fever, cough and progressive dyspnea were the main manifestations.The pulmonary signs were not obvious, however, the chest radiographs showed serious ground glass changes.Laboratory examination showed that white blood cell counts were normal, lymphocyte counts were decreased to varying degrees, while C-reactive protein, calcitonin and lipopolysaccharide increased slightly or normal.Lactate dehydrogenase significantly increased and PaO 2/FiO 2 decreased, respectively.All children combined with different degrees of heart, liver and digestive tract damage.Pneumocystis jirovecii infection was diagnosed by metagenomics next-generation sequencing(mNGS), of which one case was detected by bronchoalveolar lavage fluid, and the remaining six cases were detected by peripheral blood.After entering PICU, mechanical ventilation, intravenous injection of human immunoglobulin, and continuous renal replacement therapy were performed.None of the children used TMP-SMZ for prophylaxis outside the hospital.Among them, one case was diagnosed with PCP before entering PICU and was given TMP-SMZ for 20 days, while the remaining six patients started to receive TMP-SMZ after entering PICU.Finally, one patient was cured, three died and another three cases died after giving up treatment.The average hospitalization days were(11.28±8.78)days, and the average hospitalization costs were (78, 000±24, 000) RMB. Conclusion:Children with non-human immunodeficiency virus infected PCP usually have underlying diseases or immunodeficiency diseases.Due to non-specific manifestations, rapid progression and high mortality, clinicians should pay more attention to it.It is necessary to dynamically observe the respiratory symptoms, perform mNGS as soon as possible, and give TMP-SMZ treatment in time.TMP-SMZ prophylaxis can be given to patients who are highly suspected of PCP but unable to perform pathogenic examinations.

Objective To observe senile plaque and iron deposition in cortex and hippocampus of the Alzheimer's disease ( AD ) transgenic mice and investigate their influence on T2 relaxation time.Method All AD transgeic mice were divided into three groups: young group(2,4 months), adult group (6,8,10 months), old group (12,14,16 months), and C57BL/6J mice were as control and were scanned in order by using 4.7 T MR system.Regions of interest (ROI) corresponding to cortex, hippocampus,thalamus, striatum were manually drawn on MR images and T2 MR relaxation times of each ROI were calculated.After MR scan, these mice were decapitated and stained for iron and senile palques.The number of plaque and iron, plaque burden, iron load in cortex and hippocampus were acquired using image pro plus software.Result T2 relaxation times of each group were as following: wild type ( cortex (49.5 ± 2.1 ) ms,hippocampus (51.6 ± 1.1 ) ms ); young ( cortex ( 49.7 ± 0.5 ) ms, hippocampus ( 50.7 ± 0.7 ) ms ); adult (cortex(47.2 ±0.8) ms, hippocampus(47.7 ±0.9) ms) and old (cortex(44.6 ±0.8) ms, hippocampus (45.3 ±0.4)ms).T2 relaxation times in cortex and hippocampus of each group had statistical differences ( cortex F = 18.620, P ＜ 0.01; hippocampus F = 67.925, P ＜ 0.01 ); Compared with young group and wild type mice, T2 relaxation times in corex and hippocampus of adult group mice were decreased significantly.At the same time, T2 relaxation times in old group mice were reduced compared with adult group ( Adult vs young: cortex q =4.284, P ＜0.01, hippocampus q =7.902, P ＜0.01; adult vs wild type: cortex q =4.424, P＜0.05, hippocampus q = 11.450, P ＜0.01; old w adult: cortex q =4.812, P ＜0.01,hippocampus q = 7.034, P ＜ 0.01 ).Histochemical staining for senile plaques found that senile plaques was deposited as early as 4 month.Iron deposition in hippocampus and cortex were detected by perl-DAB as early as 6 months of age, and there was an overall increase in number and load of plaques and iron with age.A positive correlation was observed between plaque burden and iron load ( r = 0.931, P ＜ 0.01 ).At the same time, plaque burden and iron load were negatively correlated with T2 relaxation times ( plaque burden and T2 relaxation times r = - 0.884, P ＜ 0.01; iron load and T2 relaxation times r = - 0.827, P ＜ 0.01 ).Conclusion The changes of T2 relaxation time in AD transgenic mice are attributed to iron and senile plaques.MR T2 relaxation time is a sensitive marker to diagnosis for AD and screen antidementia drugs.

Objective To develop specific targeted magnetic biomarkers which can selectively mark the senile plaques in Alzheimer' s disease (AD) and verify its feasibility and validity.Methods Aβ1-40 peptide and Tat-PTD ( Tat-protein transduction domain) was binded with dextran-coated ultrasmall superparamagnetic iron oxide ( USPIO) particles.Visualization of plaques in vivo in Alzheimer transgenic mice was investigated at 7.0 Tesla using T2 sequences after intravenous administration of the targeted nanoiron contrast agent and verified by histological staining.Results The targeted nano-iron contrast agent could enter the cultured neural stem cells,and was able to accelerate T2 relaxation rates of water protons in the cells and negatively reinforce the T2 signal intensity in the labeled cells.Plaques were specifically detected in vivo by magnetic resonance imaging ( MRI) and correlated well with histological staining after injection of nano-iron contrast agent into the APP/PS1 mice.Conclusion The targeted nano-iron contrast agent has the ability of selectively labeling the senile plaques in AD brain tissues in vivo,which might enable the early detection of plaques by MRI and can be further applied in the studies of early diagnosis of AD.

Objective:To investigate the related risk factors affecting the prognosis of hemorrhagic fever with renal syndrome(HFRS) in children.Methods:A retrospective study was carried out.We selected 182 pediatric patients who met the diagnostic criteria for pediatric HFRS while hospitalized in the Intensive Care Department of the Affiliated Children′s Hospital of Xi′an Jiaotong University between July 2014 and December 2021 as the research objects.The severe and critical patients were taken as the observation group(24 cases), and the mild and moderate pediatric patients were taken as the control group(158 cases). The demographic, epidemiological data and clinically relevant indicators within 8 hours of pediatric patients after admission were collected.The 28-day death was the primary endpoint.Renal failure and pulmonary edema were secondary endpoint.The differences of clinically relevant indicators between the two groups were observed.Logistic regression was used to analyze the risk factors and receiver operating characteristic(ROC) curve was used to determine the predictive efficacy of different outcome prediction models.Results:There were no statistically significant differences in age, gender, and BMI between the two groups (all P>0.05). Compared the control group with the observation group, coagulation function indicators such as activated partial thromboplastin time (APTT)[(134±21)s vs.(164±34)s], D-dimer [(6.31±3.20)mg/L vs.(12.43±5.67)mg/L], von Willebrand factor (vWF)[(352±45)μg/L vs.(465±103)μg/L], and platelet(PLT)[(87±35)×10 9/L vs.(45±24)×10 9/L], Lactate(Lac)[(2.6±1.1)mmol/L vs.(6.0±2.0)mmol/L]were different significantly(all P<0.05). Additionally, the lymphocyte characteristic analysis indicator lymphocytes [(2 749±686)×10 6/L vs.(2 374±851)×10 6/L], CD3 + [(1 821± 487)×10 6/L vs.(1 065±539)×10 6/L], CD4 + /CD8 + (1.65±0.73)vs.(1.00±0.25), CD19 + [(559±105)×10 6/L vs.(487± 133)×10 6/L]were different significantly(all P<0.05). The inflammatory index procalcitonin(PCT) [(22±15)ng/L vs.(56±21)ng/L, P<0.05]was different significantly in two groups.The rate of continuous renaly replacement therapy, ventilator-assisted ventilation, vasoactive drugs and other treatment measures increased significantly in observation group than those in control group(all P<0.05). Multivariate logistic regression analysis was performed on the included indicators.With death as the primary endpoint, Lac, CD8 + , D-dimer, vWF and PCT were significantly associated with mortality, which were risk factors for death, while PLT and CD4 + /CD8 + were protective factors.With renal failure and pulmonary edema as secondary endpoint, CD8 + , D-dimer, Lac and PCT were risk factors for secondary endpoint.ROC curve analysis showed that the sensitivity, specificity and AUC of the risk factor prediction model related to the primary endpoint variables were 77.91%, 81.22% and 0.769, and which related to secondary endpoint variables were 87.61%, 77.59% and 0.891, respectively. Conclusion:The combinations of CD8 + , D-dimer, Lac, PCT and vWF have good predictive value for poor prognosis in children with HFRS.

Objective:To investigate the prognostic value of the ratio of veno-arterial carbon dioxide partial pressure difference to arterio-venous oxygen content difference (Pv-aCO 2/Ca-vO 2) in children with primary peritonitis-related septic shock. Methods:A retrospective study was conducted. Sixty-three children with primary peritonitis-related septic shock admitted to department of intensive care unit of the Children's Hospital Affiliated to Xi'an Jiaotong University from December 2016 to December 2021 were enrolled. The 28-day all-cause mortality was the primary endpoint event. The children were divided into survival group and death group according to the prognosis. The baseline data, blood gas analysis, blood routine, coagulation, inflammatory status, critical score and other related clinical data of the two groups were statistics. The factors affecting the prognosis were analyzed by binary Logistic regression, and the predictability of risk factors were tested by the receiver operator characteristic curve (ROC curve). The risk factors were stratified according to the cut-off, Kaplan-Meier survival curve analysis compared the prognostic differences between the groups.Results:A total of 63 children were enrolled, including 30 males and 33 females, the average age (5.6±4.0) years old, 16 cases died in 28 days, with mortality was 25.4%. There were no significant differences in gender, age, body weight and pathogen distribution between the two groups. The proportion of mechanical ventilation, surgical intervention, vasoactive drug application, and procalcitonin, C-reactive protein, activated partial thromboplastin time, serum lactate (Lac), Pv-aCO 2/Ca-vO 2, pediatric sequential organ failure assessment, pediatric risk of mortality Ⅲ in the death group were higher than those in the survival group. Platelet count, fibrinogen, mean arterial pressure were lower than those in the survival group, and the differences were statistically significant. Binary Logistic regression analysis showed that Lac and Pv-aCO 2/Ca-vO 2 were independent risk factors affecting the prognosis of children [odds ratio ( OR) and 95% confidence interval (95% CI) were 2.01 (1.15-3.21), 2.37 (1.41-3.22), respectively, both P < 0.01]. ROC curve analysis showed that the area under curve (AUC) of Lac, Pv-aCO 2/Ca-vO 2 and their combination were 0.745, 0.876 and 0.923, the sensitivity were 75%, 85% and 88%, and the specificity were 71%, 87% and 91%, respectively. Risk factors were stratified according to cut-off, and Kaplan-Meier survival curve analysis showed that the 28-day cumulative probability of survival of Lac ≥ 4 mmol/L group was lower than that in Lac < 4 mmol/L group [64.29% (18/28) vs. 82.86% (29/35), P < 0.05]. Pv-aCO 2/Ca-vO 2 ≥ 1.6 group 28-day cumulative probability of survival was less than Pv-aCO 2/Ca-vO 2 < 1.6 group [62.07% (18/29) vs. 85.29% (29/34), P < 0.01]. After a hierarchical combination of the two sets of indicator variables, the 28-day cumulative probability of survival of Pv-aCO 2/Ca-vO 2 ≥ 1.6 and Lac ≥ 4 mmol/L group significantly lower than that of the other three groups (Log-rank test, χ2 = 7.910, P = 0.017). Conclusion:Pv-aCO 2/Ca-vO 2 combined with Lac has a good predictive value for the prognosis of children with peritonitis-related septic shock.

Pulmonary artery sling (PAS) with bronchial bridge malformation is a very rare developmental malformation of vascular and trachea. In the past 2 years, we treated 3 children with pulmonary artery sling complicated with bronchial bridge, all of whom were clinically characterized by recurrent cough, asthma and dyspnea, which were confirmed by cardiac color ultrasound and chest CT three-dimensional reconstruction. All of the 3 children underwent surgical treatment, and no recurrent wheezing or respiratory tract infection occurred after surgery.

Objective:To investigate the clinical characteristics and treatment strategies of toxic epidermal necrolysis(TEN) in children.Methods:The clinical data, laboratory examination, diagnosis and treatment process and treatment outcomes of 11 children with TEN treated in PICU at Children′s Hospital of Xi′an Jiaotong University from January 2018 to June 2022 were collected and analyzed retrospectively.Results:There were five males and six females, aged from one year to 11 years old.Nine cases were caused by drugs, among which six cases were caused by antiepileptic drugs, two cases were caused by Chinese patent medicine, one case was caused by antibiotics, and the remaining two cases were caused by infection.In addition to large area of skin exfoliation, one case was complicated with corneal perforation, one case was complicated with finger (toe) nail fall off, and two cases were complicated with upper airway obstruction.All children were complicated with various degrees of heart, liver, kidney and other organ damage.Eight cases who were admitted to the department of immunology were treated with methylprednisolone and intravenous immune globulin.Three cases had no change in rash, and five cases had an enlarged range of skin lesions compared with admission, and finally all of them were transferred to PICU.Three cases were first diagnosed in PICU and were not treated with methylprednisolone and intravenous immune globulin after admission.All 11 children were given therapeutic plasma exchange in PICU.For children whose first department was PICU, the average hospitalization time of PICU was (8.00±3.00) days, the total average hospitalization time was (33.66±20.10) days, and the average hospitalization cost was (73.9±30.5) thousand yuan.For children whose first department was the immunology department, the average hospitalization time of PICU was (21.62±16.18) days, the total average hospitalization time was (41.87±16.97) days, and the average hospitalization cost was (130.8±52.2) thousand yuan.One case, because of corneal perforation, the family members asked to leave the hospital for economic reasons after the rash improved, and the rest of the children were cured and discharged.Conclusion:TEN is rare, often complicated with multiple organ dysfunction, and has a high mortality.Early administration of therapeutic plasma exchange may alleviate multiple system damage and shorten the duration of disease.

Objective: To investigate the safety and feasibility of proximal partial gastrectomy with Cheng's Giraffe esophagogastric reconstruction for the treatment of early Siewert II adenocarcinoma of esophagogastric junction (AEG). Methods: Indication of Cheng's Giraffe esophagogastric reconstruction: (1) Siewert II AEG or Siewert III AEG with diameter < 4 cm; (2) preoperative staging as cT1-2N0M0. A descriptive case series study was carried out. Clinical data of 34 patients with Siewert II AEG undergoing proximal partial gastrectomy and Cheng's Giraffe esophagogastric reconstruction at Department of Abdominal Surgery of Zhejiang Cancer Hospital and Department of Gastrointestinal Surgery, The First Affiliated Hospital of Zhejiang University of Traditional Chinese Medicine from February to July 2018 were retrospectively collected and analyzed, including 14 cases in IA stage, 11 cases in IIA stage and 8 cases in IIB stage. Brief procedure of Cheng's Giraffe esophagogastric reconstruction was as follows: Firstly, 12 cm long tubular stomach was formed by longitudinal incision 4 cm away from the great curvature of the stomach. Secondly, the gastric fundus and His angle were formed. Finally, the distance from His angle to esophagal-tubular gastric anastomosis should be more than 5 cm. The reflux disease questionare (RDQ) scores, radionuclide gastric emptying scintigraphy, and 24-hour multichannel intraluminal (MII)-pH monitoring technology were used to evaluate postoperative gastric emptying and gastroesophageal reflux. Result: All 34 patients successfully completed proximal partial gastrectomy with Cheng's Giraffe esophagogastric reconstruction, including 13 cases by open surgery and 21 cases by laparoscopic surgery. The operation time was (144.6±39.8) minutes, the blood loss during operation was (35.4±17.2) ml. No laparoscopic case was converted to open surgery and no postoperative complication was observed. The postoperative hospital stay was (8.4±2.5) days. The postoperative RDQ score was 4.4±3.1 one month after operation, and 3.3±2.5 six months after operation. Gastric-half emptying time was (67.0±21.5) minutes, and the residual ratio was (52.2±7.7)% in 1 hour, (36.4±3.1)% in 2 hours and (28.8±3.6)% in 3 hours at postoperative 1-month. The 24-hour MII-pH monitoring at postoperative 2-month revealed the frequency of acid reflux was (12.6±7.9) times, frequency of non-acid reflux was (19.6±9.7) times, DeMeester score was 5.8±2.9. Conclusion Cheng's Giraffe esophagogastric reconstruction is safe and feasible in the treatment of Siewert type II AEG, and has good dynamic and anti-reflux effects.