1.Respiratory mechanics analysis of inspiratory trigger in mechanical ventilation.
Yunzhen WU ; Na GAI ; Jingjing ZHANG
Chinese Critical Care Medicine 2023;35(10):1116-1120
OBJECTIVE:
To find out the circuit pressure and flow at the trigger point by observing the characteristics of the inspiratory trigger waveform of the ventilator, confirm the intra-alveolar pressure as the index to reflect the effort of the trigger according to the working principle of the ventilator combined with the laws of respiratory mechanics, establish the related mathematical formula, and analyze its influencing factors and logical relationship.
METHODS:
A test-lung was connected to the circuit in a PB840 ventilator and a SV600 ventilator set in pressure-support mode. The positive end-expiratory pressure (PEEP) was set at 5 cmH2O (1 cmH2O ≈ 0.098 kPa), and the wall of test-lung was pulled outwards till an inspiratory was effectively triggered separately in slow, medium, fast power, and separately in flow-trigger mode (sensitivity VTrig 3 L/min, 5 L/min) and pressure-trigger mode (sensitivity PTrig 2 cmH2O, 4 cmH2O). By adjusting the scale of the curve in the ventilator display, the loop pressure and flow corresponding to the trigger point under different triggering conditions were observed. Taking intraalveolar pressure (Pa) as the research object, the Pa (called Pa-T) needed to reach the effective trigger time (TT) was analyzed in the method of respiratory mechanics, and the amplitude of pressure change (ΔP) and the time span (ΔT) of Pa during triggering were also analyzed.
RESULTS:
(1) Corresponding relationship between pressure and flow rate at TT time: in flow-trigger mode, in slow, medium and fast trigger, the inhalation flow rate was VTrig, and the circuit pressure was separately PEEP, PEEP-Pn, and PEEP-Pn' (Pn, Pn', being the decline range, and Pn' > Pn). In pressure-trigger mode, the inhalation flow rate was 1 L/min (PB840 ventilator) or 2 L/min (SV600 ventilator), and the circuit pressure was PEEP-PTrig. (2) Calculation of Pa-T: in flow-trigger mode, in slow trigger: Pa-T = PEEP-VTrigR (R represented airway resistance). In medium trigger: Pa-T = PEEP-Pn-VTrigR. In fast trigger: Pa-T = PEEP-Pn'-VTrigR. In pressure-trigger mode: Pa-T = PEEP-PTrig-1R. (3) Calculation of ΔP: in flow trigger mode, in flow trigger: without intrinsic PEEP (PEEPi), ΔP = VTrigR; with PEEPi, ΔP = PEEPi-PEEP+VTrigR. In medium trigger: without PEEPi, ΔP = Pn+VTrigR; with PEEPi, ΔP = PEEPi-PEEP+Pn+VTrigR. In fast trigger: without PEEPi, ΔP = Pn'+VTrigR; with PEEPi, ΔP = PEEPi-PEEP+Pn'+VTrigR. In pressure-trigger mode, without PEEPi, ΔP = PTrig+1R; with PEEPi, ΔP = PEEPi-PEEP+PTrig+1R. (4) Pressure time change rate of Pa (FP): FP = ΔP/ΔT. In the same ΔP, the shorter the ΔT, the greater the triggering ability. Similarly, in the same ΔT, the bigger the ΔP, the greater the triggering ability. The FP could better reflect the patient's triggering ability.
CONCLUSIONS
The patient's inspiratory effort is reflected by three indicators: the minimum intrapulmonary pressure required for triggering, the pressure span of intrapulmonary pressure, and the pressure time change rate of intrapulmonary pressure, and formula is established, which can intuitively present the logical relationship between inspiratory trigger related factors and facilitate clinical analysis.
Humans
;
Respiration, Artificial/methods*
;
Positive-Pressure Respiration
;
Lung
;
Ventilators, Mechanical
;
Respiratory Mechanics
3.Study of a fetus with confined placental mosaicism for trisomy 2 in conjunct with fetal uniparental disomy and a literature review.
Chunqiang LIU ; Yan LYU ; Yulin JIANG ; Qingwei QI ; Xiya ZHOU ; Na HAO ; Mengmeng LI ; Mouhuizi GAI
Chinese Journal of Medical Genetics 2023;40(12):1461-1465
OBJECTIVE:
To carry out genetic analysis for a fetus with confined placental mosaicism (CPM) for trisomy 2 (T2) in conjunct with fetal uniparental disomy (UPD).
METHODS:
Amniocentesis and chromosomal karyotyping was carried out for a pregnant woman with a high risk for chromosome 2 anomalies indicated by non-invasive prenatal testing (NIPT). Single nucleotide polymorphism array (SNP-array) and trio-whole exome sequencing (Trio-WES) were carried out. Ultrasonography was used to closely monitor the fetal growth. Multifocal sampling of the placenta was performed after delivery for copy number variation sequencing (CNV-seq).
RESULTS:
The fetus was found to have a normal chromosomal karyotype. SNP-array has revealed multiple regions with loss of heterozygosity (LOH) on chromosome 2. Trio-WES confirmed the presence of maternal UPD for chromosome 2. Ultrasonography has revealed intrauterine growth restriction and oligohydramnios. Intrauterine fetal demise had occurred at 23+4 weeks of gestation. Pathological examination had failed to find salient visceral abnormality. The placenta was proved to contain complete T2 by CNV-seq.
CONCLUSION
T2 CPM can cause false positive result for NIPT and may be complicated with fetal UPD, leading to adverse obstetric outcomes such as intrauterine growth restriction, oligohydramnios and intrauterine fetal demise.
Female
;
Humans
;
Pregnancy
;
Amniocentesis
;
Chromosomes, Human, Pair 2/genetics*
;
DNA Copy Number Variations
;
Fetal Death
;
Fetal Growth Retardation/genetics*
;
Fetus
;
Mosaicism
;
Oligohydramnios
;
Placenta
;
Trisomy/genetics*
;
Uniparental Disomy/genetics*
4.Distribution of non-bacterial pathogens in 1 788 children with community-acquired pneumonia.
Shuang WANG ; Xue-Feng WANG ; Na LI ; Yue-Xin ZHANG ; Jing CHEN ; Gai-Mei WANG
Chinese Journal of Contemporary Pediatrics 2023;25(6):633-638
OBJECTIVES:
To investigate the distribution characteristics of non-bacterial pathogens in community-acquired pneumonia (CAP) in children.
METHODS:
A total of 1 788 CAP children admitted to Shenyang Children's Hospital from December 2021 to November 2022 were selected. Multiple RT-PCR and capillary electrophoresis were used to detect 10 viral pathogens and 2 atypical pathogens, and serum antibodies of Chlamydial pneumoniae (Ch) and Mycoplasma pneumoniae (MP) were detected. The distribution characteristics of different pathogens were analyzed.
RESULTS:
Among the 1 788 CAP children, 1 295 children were pathogen-positive, with a positive rate of 72.43% (1 295/1 788), including a viral pathogen positive rate of 59.68% (1 067/1 788) and an atypical pathogen positive rate of 22.04% (394/1 788). The positive rates from high to low were MP, respiratory syncytial virus (RSV), influenza B virus (IVB), human metapneumovirus (HMPV), human rhinovirus (HRV), human parainfluenza virus (HPIV), influenza A virus (IVA), bocavirus (BoV), human adenovirus (HADV), Ch, and human coronavirus (HCOV). RSV and MP were the main pathogens in spring; MP had the highest positive rate in summer, followed by IVA; HMPV had the highest positive rate in autumn; IVB and RSV were the main pathogens in winter. The positive rate of MP in girls was higher than that in boys (P<0.05), and there were no significant differences in other pathogens between genders (P>0.05). The positivity rates of certain pathogens differed among age groups (P<0.05): the positivity rate of MP was highest in the >6 year-old group; the positivity rates of RSV and Ch were highest in the <1 year-old group; the positivity rates of HPIV and IVB were highest in the 1 to <3 year-old group. RSV, MP, HRV, and HMPV were the main pathogens in children with severe pneumonia, while MP was the primary pathogen in children with lobar pneumonia, and MP, IVB, HMPV, RSV, and HRV were the top 5 pathogens in acute bronchopneumonia.
CONCLUSIONS
MP, RSV, IVB, HMPV, and HRV are the main pathogens of CAP in children, and there are certain differences in the positive rates of respiratory pathogens among children of different ages, genders, and seasons.
Humans
;
Child
;
Female
;
Male
;
Infant
;
Child, Preschool
;
Pneumonia
;
Respiratory Syncytial Virus, Human
;
Antibodies
;
Community-Acquired Infections
;
Hospitalization
;
Influenza B virus
;
Mycoplasma pneumoniae
5.Silk fibroin/collagen composite hydrogels with different matrix stiffness influence the growth and phenotype of human mammary epithelial cells.
Yi-Ning ZHANG ; Hui JIAO ; Li-Na GUO ; Xin-Yu MA ; Gao-Cheng GAI ; Jin-Tao ZHANG ; Wen-Qing YANG ; Xiu-Li WANG
Acta Physiologica Sinica 2022;74(3):381-391
Extracellular matrix (ECM) stiffness is closely related to the physiological and pathological states of breast tissue. The current study was aimed to investigate the effect of silk fibroin/collagen composite hydrogels with adjustable matrix stiffness on the growth and phenotype of normal breast epithelial cells. In this study, the enzymatic reaction of horseradish peroxidase (HRP) with hydrogen peroxide (H2O2) was used to change the degree of cross-linking of the silk fibroin solution. The rotational rheometer was used to characterize the composite hydrogel's biomechanical properties. Human normal mammary epithelial cell line MCF-10A were inoculated into composite hydrogels with various stiffness (19.10-4 932.36 Pa) to construct a three dimensional (3D) culture system of mammary epithelial cells. The CCK-8 assay was applied to detect the cell proliferation rate and active states in each group. Hematoxylin-Eosin (HE) staining and whole-mount magenta staining were used for histological evaluation of cell morphology and distribution. The results showed that with the increase of matrix stiffness, MCF-10A cells exhibited inhibited proliferation rate, decreased formation of acinus structures and increased branching structures. Meanwhile, with the increase of matrix stiffness, the polarity of MCF-10A cells was impeded. And the increase of matrix stiffness up-regulated the expression levels of mmp-2, mmp-3, and mmp-9 in MCF-10A cells. Among the genes related to epithelial-mesenchymal transition (EMT), the expression level of the epithelial marker gene E-cadherin was significantly down-regulated, while the interstitial cell marker gene Vimentin was up-regulated, and the expression levels of Snail, Wnt5b and Integrin β1 in the Wnt pathway were up-regulated. These results suggest that the silk fibroin/collagen composite hydrogels with adjustable matrix stiffness regulates the proliferation and the phenotype of MCF-10A cells. The effects of increased matrix stiffness may be closely related to the changes of the polar structures and function of MCF-10A cells, as well as the occurrence of ECM-remodeling and EMT.
Collagen/metabolism*
;
Epithelial Cells/metabolism*
;
Fibroins/pharmacology*
;
Humans
;
Hydrogels/metabolism*
;
Hydrogen Peroxide
;
Phenotype
6.Effect of electroacupuncture pretreatment on hippocampal oxidative stress in aged mice with postoperative cognitive dysfunction.
Na LI ; Su-Yun HONG ; Jun LI ; Gai-Mei WANG ; Zhe LIU ; Yi LIANG
Chinese Acupuncture & Moxibustion 2021;41(6):645-650
OBJECTIVE:
To observe the effect of electroacupuncture (EA) pretreatment on hippocampal oxidative stress in aged mice with postoperative cognitive dysfunction (POCD) and explore the relevant mechanism of EA pretreatment on the improvement of learning and memory in POCD aged mice.
METHODS:
A total of 72 healthy male aged mice were randomized into a blank group, a model group, a medication group and an EA group, 18 mice in each one. In each group, 1-day, 3-day and 7-day subgroups were divided separately, 6 mice in each subgroup. In the EA group, "Baihui" (GV 20) and "Dazhui" (GV 14) were selected and stimulated with EA, using continuous wave (15 Hz, 1 mA), continuously for 30 min, once a day, for 5 days consecutively. In the medication group, 10% minocycline was injected intraperitoneally, 40 mg/kg, once a day, consecutively for 5 days. In the blank and the control group, intraperitoneal injection of 0.9% sodium chloride solution was given with equal dosage. Except the blank group, at the end of intervention, partial hepatectomy was conducted to establish POCD model in the rest groups. Morris water maze test was adopted to evaluate the learning and memory ability of the aged mice. ELISA was used to determine the contents of reactive oxygen species (ROS) and malondialdehyde (MDA) in the hippocampal tissue. Western blot method was applied to detect the protein expressions of superoxide dismutase 1 (SOD 1) and superoxide dismutase 2 (SOD 2) in the hippocampal tissue.
RESULTS:
Compared with the blank group, the percentage of platform quadrant residence time was obviously reduced in the mice in the model group (
CONCLUSION
Electroacupuncture pretreatment at "Baihui" (GV 20) and "Dazhui" (GV 14) may increase the learning and memory ability of POCD aged mice, which is probably related to the decrease of oxidative stress and the strengthening of hippocampal antioxidant capacity.
Animals
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Electroacupuncture
;
Hippocampus
;
Male
;
Memory
;
Mice
;
Oxidative Stress
;
Postoperative Cognitive Complications
7.A Real-world Study on the Assessment of Pathological Characteristics and Targeted Therapeutic Effect of Non-small Cell Lung Cancer Patients with Positive Driving Genes and High PD-L1 Expression.
Hui ZHANG ; Xinjie YANG ; Kun LI ; Jinghui WANG ; Jialin LV ; Xi LI ; Xinyong ZHANG ; Na QIN ; Quan ZHANG ; Yuhua WU ; Li MA ; Fei GAI ; Ying HU ; Shucai ZHANG
Chinese Journal of Lung Cancer 2021;24(2):78-87
BACKGROUND:
Targeted therapy for patients with driver genes positive and immunotherapy for patients with driver gene-negative but high programmed death ligand 1 (PD-L1) expression are the standards of first-line treatment for patients with advanced non-small cell lung cancer (NSCLC). The treatment options for patients with driver gene positive and high PD-L1 expression are still worth exploring.
METHODS:
The characteristics of 315 patients with NSCLC were identified to analyze the clinicopathological characteristics of patients with driver gene positive and high PD-L1 expression, and the efficacy of targeted therapy.
RESULTS:
Among the 315 patients, the total positive rate of driver genes was 62.2%, and the high PD-L1 expression rate (≥50.0%) was 11.2%. The proportion of patients with driver gene positive and high PD-L1 expression was 10.7%. PD-L1 was highly expressed in patients with epidermal growth factor receptor (EGFR) mutation, KRAS mutation, ALK fusion, BRAF mutation, and MET 14 exon skip mutation, the proportions were 7.8% (11/141), 18.2% (4/22), and 23.1%, (3/13), 50.0% (2/4) and 100.0% (1/1) respectively. EGFR mutation positive with PD-L1 high expression was mainly in patients with stage IV lung adenocarcinoma. KRAS mutation positive with PD-L1 high expression was mainly in patients with a history of smoking. Among them, two patients were followed in detail for targeted therapy, who with ALK fusion-positive and PD-L1 high expression (90.0%), EGFR L858R mutation and PD-L1 high expression (70.0%) respectively. The total OS of the patients was 5 months, 2 months.
CONCLUSIONS
The high PD-L1 expression rate in NSCLC patients with different driver gene mutations was variable, which maybe correlated with distinct clinicopathological characteristics. Patients with sensitive mutations and high PD-L1 expression may be less benefit from targeted therapy and have poor prognosis.
8.A theoretical analysis of respiratory mechanics in mechanical ventilation
Yunzhen WU ; Na GAI ; Wencai HU ; Haisheng GUO
Chinese Critical Care Medicine 2021;33(11):1405-1408
As a non-physiological way of ventilation, mechanical ventilation has a great effect on the respiratory mechanics. The biggest problem of artificial airway is that it brings extra airway resistance to the respiratory tract. For different parts of the lung, positive pressure ventilation could cause different mechanic states. We can find the formation and influencing factors of transpulmonary pressure, transchest wall pressure, trans-lung-chest pressure, trans-diaphragmatic pressure, trans-pulmonary-diaphragmatic pressure, intrapleural pressure, plateau pressure and driving pressure, by analyzing the mechanic state in a unit area of the chest or diaphragm position in the way of basic mechanics. It is obviously different in the pulmonary pressure gradient caused by inspiratory driving between in spontaneous breathing and in mechanical ventilation. The pressure is transmitted from the periphery to the center in spontaneous breathing in physiological state, playing a traction role for lung tissue. The pressure is transmitted from the center to the periphery in positive pressure ventilation without spontaneous breathing, playing a pushing role for lung tissue. It can be divided into two stages in positive pressure ventilation with spontaneous breathing. The first stage is from inspiratory trigger effort to trigger sensitivity. It is similar to spontaneous inspiration in physiological state. The pressure gradient in this stage is from the peripheral to center. But the period is very short. The second stage is the positive pressure ventilation progress after the trigger sensitivity. The pressure gradient is caused by the pulling of the patient's spontaneous inhalation and the pushing of the positive pressure ventilation of the ventilator. There is a certain complementarity in the distribution and transmission of pressure, especially for non-physiological positive pressure ventilation. Therefore, through these basic mechanical analysis, clinical medical staff can better understand the impact of mechanical ventilation on respiratory mechanics.
9. Anther Transcriptomics and Expression Analysis of Genes Related to Anthocyanin Synthesis in Blue Labeled Genic Male Sterile Wheat
Xiao-Yu FENG ; Na NIU ; Yu-Long SONG ; Shou-Cai MA ; Peng-Ke WANG ; Gai-Sheng ZHANG ; Jun-Wei WANG ; Jian DONG ; Jian-Chao ZHANG
Chinese Journal of Biochemistry and Molecular Biology 2021;37(4):504-515
In order to reveal the molecular mechanism of blue labeled genic male sterility (BM-type GMS) and utilize the heterosis of BM-type GMS, we used the anthers of white-seed plants WS (sterile) and light blue seed plants WF (normal fertility) as experimental materials to analyze the differences in gene expression between them by transcriptome technology. And we also verified the genes expressed in anthocyanin synthesis in this study. Compared with WF, a total of 2352 differentially expressed genes were detected in WS. According to GO functional annotation, these genes could be divided into 3 categories and 43 subgroups. They are mainly involved in biosynthesis, phenylpropane metabolism, L-phenylalanine catabolism, membrane components, plasma membrane, cytoplasm, ATP binding, protein serine/threonine kinase activity, etc. KEGG pathway analysis showed that there were 159 genes enriched in the phenylpropanoid biosynthesis pathway, followed by the phenylalanine pathway, including 136 differentially expressed genes. Other genes are also involved a variety of amino acid metabolism, purine metabolism, pyrimidine metabolism and sugar metabolism pathway. Related to anthocyanin metabolism, several structural genes of key enzymes were differentially expressed, and most of them were up-regulated in WF, while only Flavanone 3-hydroxylase (F3H) and colorless anthocyanin dioxygenase (ANS) were down-regulated. Quantitative real-time PCR showed that the expression of 10 genes related to anthocyanin metabolism had the same trend as that in transcriptome sequencing data. Sequence homology analysis showed that the two selected transcription factors (DN48762c2g1 and DN25944c0g1) are clustered into the same cluster as the transcription factors regulating anthocyanin biosynthesis in maize, rice and Arabidopsis thaliana, which might be candidate genes for the blue aleurone layer of light blue seed plants in wheat. And fluorescence quantitative analysis showed that the expression level of DN48762c2g1 and DN25944c0g1 in WF was significantly higher than that in WS. In conclusion, the genes related to the anthocyanin biosynthesis pathway are not only related to the blue grain trait, but also may be involved in the anther abortion of BM-type GMS.
10.Individualized vancomycin dosing for a patient diagnosed as severe acute pancreatitis with concurrent extracorporeal membrane oxygenation and continuous veno-venous hemofiltration therapy: a case report.
Na HE ; Ying Ying YAN ; Ying Qiu YING ; Min YI ; Gai Qi YAO ; Qing Gang GE ; Suo Di ZHAI
Journal of Peking University(Health Sciences) 2018;50(5):915-920
Pharmacokinetic parameters can be significantly altered for acute kidney injury (AKI), extracorporeal membrane oxygenation (ECMO) and continuous veno-venous hemofiltration therapy (CVVH). Here we reported a case of individualized vancomycin dosing for a patient diagnosed as severe acute pancreatitis treated with concurrent ECMO and CVVH. A 65 kg 32-year-old woman was admitted to hospital presented with severe acute pancreatitis (SAP), respiratory failure, metabotropic acidosis and hyperkalemia. She was admitted to intensive care unit (ICU) on hospital day 1 and was initiated on CVVH. She progressed to multiple organ dysfunction syndrome (MODS) and acute respiratory distress syndrome (ARDS) on ICU day 2, and veno-venous ECMO was instituted. Several catheters were inserted into the body to support ECMO, CVVH and pulse indicator continuous cardiac output (PiCCO), so vancomycin was prescribed empirically on ICU day 3 for prevention of catheter-related infection. Given the residual renal function and continuous hemofiltration intensity on day 3, vancomycin bolus of 1 000 mg was prescribed, followed by a maintenance dose of 500 mg every 8 hours. On ICU day 4, a vancomycin trough serum concentration of 14.1 mg/L was obtained before the fourth dose, which was within the target range of 10-20 mg/L. By ICU day 7, vancomycin dosage was elevated to 1.0 g every 12 hours because of aggravated infection and improved kidney function. On ICU day 14, a vancomycin trough serum concentration of 17 mg/L was obtained. Her white blood cell (WBC) and neutrophil percentage (Neut%) dropped to the normal level by ICU day 19. This vancomycin regimen was successful in providing a target attainment of trough serum concentration ranging from 10-20 mg/L quickly and in controlling infection-related symptoms and signs properly. With the help of this case report we want to call attention to the clinically significant alteration in vancomycin pharmacokinetics among critically ill patients. Individualized vancomycin dosing regimens and therapeutic drug monitoring are necessary for critically ill patients receiving CVVH and ECMO to ensure that the target serum vancomycin levels are reached to adequately treat the infection and avoid nephrotoxicity.
Adult
;
Anti-Bacterial Agents/administration & dosage*
;
Critical Illness
;
Extracorporeal Membrane Oxygenation
;
Female
;
Hemofiltration
;
Humans
;
Pancreatitis/drug therapy*
;
Vancomycin/administration & dosage*

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