Objective:To explore the influence of injection methods of different contrast agents on CMR image quality,and further optimize"one-stop"examination process under the premise of the analysis for high-pressure bolus pressure curve of contrast-enhanced(CE)cardiac magnetic resonance(CMR).Methods:The data of CMR examination of 70 patients with old myocardial infarction who admitted to the department of emergency of Xuanwu Hospital,Capital Medical University from December 2023 to December 2024 were selected as research objects.They were divided into an observation group and a control group by a simple randomization method,with 35 cases in each group.The observation group adopted gadolinium contrast agent injection with double-phase double-flow,with two bolus injections at 4 ml/s and 2 ml/s sequentially.The control group adopted the injection with single-phase double-flow,with only one bolus injection at 4 ml/s.The dynamic pressure time curve was drawn,and the total bolus dose and pressure peak of two kinds of injection methods were compared.The residual liquid samples of the observation group and the control group were collected after injection of contrast agent was conducted.After the residual liquids of 10 ml,20 ml and 30 ml were derived respectively,the T1 mapping sequence was used to collect signal intensity values,and to compared the difference of that between two groups.The signal-to-noise ratio(SNR)of left ventricular blood pool,infarcted myocardium and distal myocardium,and the contrast-to-noise ratios(CNR)between infarcted myocardium and blood pool,and between distal myocardium and blood pool were compared between the observation group and the control group.Results:There was no statistical difference in the total dose of bolus injection between the observation group and the control group(P>0.05).The peak value of the pressure of bolus injection in the observation group and control group were respectively(87.4±11.3)pound force per square inch(PSI)and(104.0±20.1)PSI,and the difference was statistically significant(t=5.81,P<0.05).T1 signal intensity values of 10 ml residual liquid and 20 mL residual liquid were respectively 1984.43±70.26 and 2190.56±195.96 in observation group,and they were respectively 1203.36±184.99 and 2884.64±349.39 in control group,and the differences were significant(t=-3.57,6.03,P<0.05).The T1 signal intensity value of 30mL residual fluid sample was 4371.75±75.16 in observation group,and that was 4261.86±110.68 in control group,and the difference was no significant(P>0.05).The SNR value of blood pool was(4.88±1.01)in observation group,which was lower than(8.25±1.36)in control group,and the difference of that between two groups was significant(t=6.11,P<0.05).The CNR values of infarcted myocardium and blood pool,of remote myocardium and blood pool between two groups were statistically significant(t=-4.79,-5.39,P<0.05).Conclusion:The contrast agent of high-pressure bolus injection with dual-phase dual-flow method can not only explore the time window of the extravasation of contrast agent,but also improve the SNR and the CNR of CMR images,and further optimize the CMR examination process.

Objective:To explore the influence of injection methods of different contrast agents on CMR image quality,and further optimize"one-stop"examination process under the premise of the analysis for high-pressure bolus pressure curve of contrast-enhanced(CE)cardiac magnetic resonance(CMR).Methods:The data of CMR examination of 70 patients with old myocardial infarction who admitted to the department of emergency of Xuanwu Hospital,Capital Medical University from December 2023 to December 2024 were selected as research objects.They were divided into an observation group and a control group by a simple randomization method,with 35 cases in each group.The observation group adopted gadolinium contrast agent injection with double-phase double-flow,with two bolus injections at 4 ml/s and 2 ml/s sequentially.The control group adopted the injection with single-phase double-flow,with only one bolus injection at 4 ml/s.The dynamic pressure time curve was drawn,and the total bolus dose and pressure peak of two kinds of injection methods were compared.The residual liquid samples of the observation group and the control group were collected after injection of contrast agent was conducted.After the residual liquids of 10 ml,20 ml and 30 ml were derived respectively,the T1 mapping sequence was used to collect signal intensity values,and to compared the difference of that between two groups.The signal-to-noise ratio(SNR)of left ventricular blood pool,infarcted myocardium and distal myocardium,and the contrast-to-noise ratios(CNR)between infarcted myocardium and blood pool,and between distal myocardium and blood pool were compared between the observation group and the control group.Results:There was no statistical difference in the total dose of bolus injection between the observation group and the control group(P>0.05).The peak value of the pressure of bolus injection in the observation group and control group were respectively(87.4±11.3)pound force per square inch(PSI)and(104.0±20.1)PSI,and the difference was statistically significant(t=5.81,P<0.05).T1 signal intensity values of 10 ml residual liquid and 20 mL residual liquid were respectively 1984.43±70.26 and 2190.56±195.96 in observation group,and they were respectively 1203.36±184.99 and 2884.64±349.39 in control group,and the differences were significant(t=-3.57,6.03,P<0.05).The T1 signal intensity value of 30mL residual fluid sample was 4371.75±75.16 in observation group,and that was 4261.86±110.68 in control group,and the difference was no significant(P>0.05).The SNR value of blood pool was(4.88±1.01)in observation group,which was lower than(8.25±1.36)in control group,and the difference of that between two groups was significant(t=6.11,P<0.05).The CNR values of infarcted myocardium and blood pool,of remote myocardium and blood pool between two groups were statistically significant(t=-4.79,-5.39,P<0.05).Conclusion:The contrast agent of high-pressure bolus injection with dual-phase dual-flow method can not only explore the time window of the extravasation of contrast agent,but also improve the SNR and the CNR of CMR images,and further optimize the CMR examination process.

Objective: To identify the risk factors in mortality of pediatric acute respiratory distress syndrome (PARDS) in pediatric intensive care unit (PICU). Methods: Second analysis of the data collected in the "efficacy of pulmonary surfactant (PS) in the treatment of children with moderate to severe PARDS" program. Retrospective case summary of the risk factors of mortality of children with moderate to severe PARDS who admitted in 14 participating tertiary PICU between December 2016 to December 2021. Differences in general condition, underlying diseases, oxygenation index, and mechanical ventilation were compared after the group was divided by survival at PICU discharge. When comparing between groups, the Mann-Whitney U test was used for measurement data, and the chi-square test was used for counting data. Receiver Operating Characteristic (ROC) curves were used to assess the accuracy of oxygen index (OI) in predicting mortality. Multivariate Logistic regression analysis was used to identify the risk factors for mortality. Results: Among 101 children with moderate to severe PARDS, 63 (62.4%) were males, 38 (37.6%) were females, aged (12±8) months. There were 23 cases in the non-survival group and 78 cases in the survival group. The combined rates of underlying diseases (52.2% (12/23) vs. 29.5% (23/78), χ²=4.04, P=0.045) and immune deficiency (30.4% (7/23) vs. 11.5% (9/78), χ²=4.76, P=0.029) in non-survival patients were significantly higher than those in survival patients, while the use of pulmonary surfactant (PS) was significantly lower (8.7% (2/23) vs. 41.0% (32/78), χ²=8.31, P=0.004). No significant differences existed in age, sex, pediatric critical illness score, etiology of PARDS, mechanical ventilation mode and fluid balance within 72 h (all P>0.05). OI on the first day (11.9(8.3, 17.1) vs.15.5(11.7, 23.0)), the second day (10.1(7.6, 16.6) vs.14.8(9.3, 26.2)) and the third day (9.2(6.6, 16.6) vs. 16.7(11.2, 31.4)) after PARDS identified were all higher in non-survival group compared to survival group (Z=-2.70, -2.52, -3.79 respectively, all P<0.05), and the improvement of OI in non-survival group was worse (0.03(-0.32, 0.31) vs. 0.32(-0.02, 0.56), Z=-2.49, P=0.013). ROC curve analysis showed that the OI on the thind day was more appropriate in predicting in-hospital mortality (area under the curve= 0.76, standard error 0.05,95%CI 0.65-0.87,P<0.001). When OI was set at 11.1, the sensitivity was 78.3% (95%CI 58.1%-90.3%), and the specificity was 60.3% (95%CI 49.2%-70.4%). Multivariate Logistic regression analysis showed that after adjusting for age, sex, pediatric critical illness score and fluid load within 72 h, no use of PS (OR=11.26, 95%CI 2.19-57.95, P=0.004), OI value on the third day (OR=7.93, 95%CI 1.51-41.69, P=0.014), and companied with immunodeficiency (OR=4.72, 95%CI 1.17-19.02, P=0.029) were independent risk factors for mortality in children with PARDS. Conclusions: The mortality of patients with moderate to severe PARDS is high, and immunodeficiency, no use of PS and OI on the third day after PARDS identified are the independent risk factors related to mortality. The OI on the third day after PARDS identified could be used to predict mortality.
Female ; Male ; Humans ; Child, Preschool ; Infant ; Child ; Critical Illness ; Pulmonary Surfactants/therapeutic use* ; Retrospective Studies ; Risk Factors ; Respiratory Distress Syndrome/therapy*

OBJECTIVETo observe the effect of the human amniotic membrane (HAM) loaded with human amniotic mesenchymal stem cells (hAMSCs) on the skin wounds of SD rats.

METHODSThe amniotic epithelial cells were removed by trypsin digestion, hAMSCs were loaded onto HAM and then covered on rats' skin defects. The wound healing was observed by HE staining and immunohistochemistry, and the results were compared with the amniotic membrane group and blank control group.

RESULTSThe average wound healing time was (18.3 +/- 0.9) d in the HAM load with hAMSCs group, which was significantly faster than those in the blank control group [(26.4 +/- 0.7) d, P < 0.01] and the amniotic membrane group [(21.5 +/- 1.2) d, P < 0.05]. After 11 d and 14 d, the wound healing rates in the HAM load with hAMSCs group were (81.5 +/- 7.2)% and (94.3 +/- 3.6)%, respectively, which were significantly higher than those in the blank control group [(48.5 +/- 3.2)% and (74.3 +/- 4.3 )%] and the amniotic membrane group [(68.5 +/- 4.5)% and (86.8 +/- 4.8)%] (all P < 0.01). Skin biopsy/HE staining confirmed that the quality of wound healing in the HAM load with hAMSCs group was significantly better than in the amniotic membrane group and the blank control group. Immunohistochemical staining showed that the number of CK19-positive epidermal stem cells in the HAM load with hAMSCs group (48.2 +/- 3.2) was significantly larger than those in the amniotic membrane group (37.7 +/- 3.1) (P < 0.05) and the blank control group (29.6 +/- 2.4) (P < 0.01). Furthermore, the vascular endothelial growth factor expression (64.5 +/- 4.5) in the HAM load with hAMSCs group was also significantly higher than those in the amniotic membrane group (52.6 +/- 3.8) (P < 0.05) and the blank control group (40.7 +/- 3.1) (P < 0.01).

CONCLUSIONHAM loaded with hAMSCs may promote the repair of skin wounds by promoting the regeneration of epidermal stem cells and capillaries.

Amnion ; cytology ; Animals ; Cells, Cultured ; Disease Models, Animal ; Humans ; Male ; Mesenchymal Stem Cell Transplantation ; Rats ; Rats, Sprague-Dawley ; Skin ; injuries ; physiopathology ; Wound Healing

OBJECTIVETo establish the method of isolation, purification, and identification of human amniotic mesenchymal stem cells (hAMSCs).

METHODShAMSCs were isolated from human amniotic membrane by trypsin-collagenase digestion, and cultured in Dulbecco's modified Eagle's medium/F12 medium supplemented with 10% fetal bovine serum. Phenotypic characteristics of these cells were analyzed by means of immunocytochemistry and flow cytometry.

RESULTSThe cells successfully isolated from human amniotic membrane expressed representative mesenchymal cell surface markers CD44, CD90, and vimentin, but not CD45.

CONCLUSIONSThis study establishes a potential method for isolation of hAMSCs from human amnion,in vitro culture, and identification. The isolated cells show phenotypic characteristics of mesenchymal stem cells.

Amnion ; cytology ; Cell Culture Techniques ; Flow Cytometry ; Humans ; Immunohistochemistry ; Mesenchymal Stromal Cells ; cytology