Objective To establish a stable,reliable,and clinically relevant porcine model of endotoxin-induced acute respiratory distress syndrome(ARDS).Methods Ten 8-month-old male Bama minipigs were deeply sedated,followed by invasive mechanical ventilation and electrocardiographic monitoring.Lipopolysaccharide(LPS)was intravenously pumped at 600 μg/(kg·h)for 3 hours,then maintained at 15 μg/(kg·h)thereafter.Dynamic monitoring was performed at five time points after LPS injection(LPS 0,1,3,5,and 8 h),including arterial blood gas analysis and chest computed tomography(CT)scans.Pathological examination of lung tissues obtained via bronchoscopic biopsy(HE staining and transmission electron microscopy)was conducted.These indicators were comprehensively used to evaluate the success of the animal model.Results At 5 hours after LPS administration,8 minipigs developed symptoms such as skin cyanosis,elevated body temperature,and respiratory distress.The oxygenation index decreased to<300 mmHg.Chest CT scans showed diffuse pulmonary infiltrates.Histopathology revealed alveolar edema and hyaline membrane formation.Transmission electron microscopy demonstrated disruption of pulmonary blood-air barrier,depletion of lamellar bodies in type Ⅱ pneumocytes,inflammatory cell infiltration,and exudation of plasma proteins and fibrin.Compared with LPS 0 h,at LPS 8 h,the oxygenation index and arterial blood pH were significantly decreased(P<0.001),while blood lactic acid and serum potassium were significantly increased(P<0.05);serum calcium and base excess were significantly decreased(P<0.05),and the lung injury score based on HE-stained lung sections was significantly increased(P<0.01).Conclusion The porcine ARDS model established by continuous LPS injection can dynamically simulate the pathophysiological characteristics and typical pathological manifestations of clinical septic ARDS,making it an effective tool to study the pathogenesis,prevention,and treatment strategies of septic ARDS.

Amino acid surfactants (AAS) have excellent properties such as low toxicity,antibacterial,mildness,and corrosion resistance. In recent years,they have been widely applied in the field of daily chemicals,food and pharmaceutical industry. It is pointed out that the structure at molecular level largely affects the physical and chemical properties of AAS materials. In this work,the structures of solid-state N-lauroyl-L-alanine (NLLA) including intermolecular interactions,molecular local dynamics and molecular assembly were investigated by a variety of solid-state nuclear magnetic resonance (SSNMR) techniques. Based on 2D 1H-1H double quantum-single quantum (2D 1H-1H DQ-SQ),1H-1H DQ sideband pattern and molecular simulation,it was found that there was a stable intermolecular hydrogen bond formed between the carboxyl units of two NLLA molecules. Combined with the study of 2D frequency switched Lee—Goldberg heteronuclear correlation (2D 13C-1H FSLG-HETCOR) and 13C T1,another type of hydrogen bond was probed,which existed between amide units of neighboring molecules. In addition,the conformation of alkyl chain ends was investigated. According to 1D 13C{1H}cross polarization/magic angle spinning (CP/MAS) and 2D 13C-1H FSLG-HETCOR spectra,it was revealed that the alkyl-chain ends had both gauche and trans conformations. Moreover,the trans conformation showed two distinct 13C chemical shifts,originated from two NLLA molecular assembly forms. Accordingly,two NLLA molecular assembly structures were suggested which were transoid form and cisoid form. This work provided a SSNMR investigation strategy for characterizing the molecular local structure and dynamics of AAS materials,which helped task of researching and developing materials with improved chemical and physical properties.

Objective To explore the mechanical behavior of cancellous bone under the interaction of whole-body low-magnitude high-frequency vibration(LMHFV)parameters,in order to provide theoretical guidance for the clinical treatment of disuse osteoporosis.Methods A three-dimensional reconstruction model was established for the cancellous bone of the mid femur by Mimics software,which was then imported into Comsol software to form a three-dimensional fluid-solid coupling finite element model.Twelve scenarios with the vibration acceleration amplitude(a)being 0.015×g,0.02×g,0.03×g and vibration frequency(f)being 30,45,60 and 100 Hz were set up for the simulation study to analyze the distribution rules of the hydrodynamic microenvironment,the stresses and the deformation displacements of cancellous bone under the interaction of LMHFV parameters.Results The bone marrow flow velocity on the surface of trabeculae and deformation displacement of bone matrix increased with the rising of a and decreased with the growing of f.Trabeculae gained high mean values of deformation displacement in case of the vibration scenario(0.015×g/0.02×g/0.03×g,30 Hz),and had high von Mises stress when LMHFV parameters were restricted within(0.02×g to 0.03×g,30 Hz to 35 Hz).Conclusion Whole-body LMHFV significantly improves the force and hydrodynamic environment of cancellous bone,and force-mediated osteoblast bioactivity can be enhanced by rationally modulating LMHFV parameters during clinical processes so as to promote osteogenesis.[Chinese Medical Equipment Journal,2024,45(7):17-23]

Objective To investigate the risk factors for bronchopulmonary dysplasia(BPD)in twin preterm infants with a gestational age of<34 weeks,and to provide a basis for early identification of BPD in twin preterm infants in clinical practice.Methods A retrospective analysis was performed for the twin preterm infants with a gestational age of<34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020.According to their conditions,they were divided into group A(both twins had BPD),group B(only one twin had BPD),and group C(neither twin had BPD).The risk factors for BPD in twin preterm infants were analyzed.Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins.Results A total of 904 pairs of twins with a gestational age of<34 weeks were included in this study.The multivariate logistic regression analysis showed that compared with group C,birth weight discordance of>25%between the twins was an independent risk factor for BPD in one of the twins(OR=3.370,95%CI:1.500-7.568,P<0.05),and high gestational age at birth was a protective factor against BPD(P<0.05).The conditional logistic regression analysis of group B showed that small-for-gestational-age(SGA)birth was an independent risk factor for BPD in individual twins(OR=5.017,95%CI:1.040-24.190,P<0.05).Conclusions The development of BPD in twin preterm infants is associated with gestational age,birth weight discordance between the twins,and SGA birth.

Objective To establish antemortem and postmortem injury models in nude mice,observe the morphological changes of the wounds and the changes of the microbial communities in the wounds at different time points after the injury,and analyze the differences between antemortem and postmor-tem wounds.Methods Abdominal injury models were established in 48 BALB/c nude mice,which were classified into antemortem injury,4 h and 72 h postmortem injury groups,and the gross manifesta-tions and histopathological changes were observed on days 1,3,5,8,11 and 15 after injury.The mi-crobial communities in the wounds were analyzed by 16S rRNA sequencing technology.QIIME 2 soft-ware was used to calculate Shannon and Observed species indices.The Kruskal-Wallis test was used to determine statistical differences in α-diversity between groups.Jaccard similarity coefficients were calculated by using R v4.3.0 software and applied to the principal co-ordinates analysis to demonstrate inter-sample differences.Permutational multivariate analysis of variance(PERMANOVA)was used to analyze the differences between groups in the composition of bacterial colonies,and R2 values were calculated.Results On days 8,11 and 15 after injury,the antemortem and postmortem injuries could not be differentiated by morphological examination;the Shannon index and Observed species index were statistically different between the antemortem injury group and the 72 h postmortem injury group;the Jaccard similarity coefficient of the microbial community was statistically different between the an-temortem injury group and the 72 h postmortem injury group.The PERMANOVA R2 value gradually increased with the extension of time(0.22-0.61).Conclusion Through the analysis of the wound mi-crobial community,the microbial composition of wounds at different time points can be identified and compared,which provides a new perspective and method for the differentiation of antemortem injuries from postmortem injuries,with good application prospects.

Humans ; Blast Crisis/genetics* ; Leukemia, Promyelocytic, Acute/genetics* ; Oncogene Proteins, Fusion/genetics* ; Tretinoin

Child ; Humans ; Acquired Immunodeficiency Syndrome/drug therapy* ; Retrospective Studies ; Anti-Retroviral Agents/therapeutic use* ; HIV Infections/epidemiology* ; China/epidemiology* ; Anti-HIV Agents/therapeutic use*

Humans ; Multiple Myeloma/drug therapy* ; Feasibility Studies ; Antibodies, Monoclonal/adverse effects* ; Dexamethasone/therapeutic use* ; Antineoplastic Combined Chemotherapy Protocols

OBJECTIVES: To study the efficacy and safety of domestic generic levetiracetam in replacement of brand-name levetiracetam in the treatment of children with epilepsy. METHODS: A retrospective analysis was performed on the medical data of 154 children with epilepsy who received domestic generic levetiracetam in the inpatient or outpatient service of Guangdong Provincial People's Hospital from May 2019 to December 2020. Domestic generic levetiracetam and brand-name levetiracetam were compared in terms of efficacy and safety. RESULTS: For these 154 children, the epilepsy control rate was 77.3% (119/154) at baseline. At 6 months after switching to domestic generic levetiracetam, the epilepsy control rate reached 83.8% (129/154), which showed a significant increase (P<0.05). There was no significant change in the frequency of seizures from baseline to 6 months after switching (P>0.05). The incidence of refractory epilepsy in children with no response after switching treatment was significantly higher than that in children with response (P<0.05). Before switching, only 1 child (0.6%) experienced somnolence, while after switching, 3 children (1.9%) experienced mild adverse drug reactions, including dizziness, somnolence, irritability, and bad temper. CONCLUSIONS Switching from brand-name to generic levetiracetam is safe and effective and holds promise for clinical application, but more prospective randomized controlled trials are required in future.
Child ; Epilepsy/drug therapy* ; Humans ; Levetiracetam ; Prospective Studies ; Retrospective Studies ; Seizures

Objective: To study the clinicopathological features, immunophenotype, molecular changes, differential diagnosis and prognosis of eosinophilic vacuolated tumor (EVT) of the kidney. Methods: Four cases were collected retrospectively from 2014 to 2020 at Ningbo Diagnostic Pathology Center. The clinicopathologic features and immunophenotypic profile were studied by light microscopy and immunohistochemistry. Targeted next-generation sequencing (NGS) panel was used to detect cancer-associated mutation. Follow-up and literature review were also performed. Results: Among the 4 patients studied,2 were males and 2 were females. The age of the patients ranged from 44 to 63 years (the mean age: 51 years).Tumor size ranged from 1.5 to 4.2 cm (mean: 2.3 cm). Microscopically, tumors were well-circumscribed, unencapsulated. Thick-walled vessels and entrapped renal tubules were found within or at the periphery of the tumors. The tumors were predominantly composed of nest pattern, and focal tubular pattern. The tumor cells exhibited abundant, eosinophilic, granular cytoplasm and conspicuous, large nucleoli. Prominent intracytoplasmic vacuoles were seen. These cytoplasmic vacuoles varied in size and frequently coalesced into a large space. Loose fibromatous or hyaline stroma was focally noted. Immunohistochemically, the tumor cells in all cases exhibited a CD117+/CK7-phenotype. All cases were positive for CD10 and p504s. MTOR, S6 and cathepsin K were positive in 4 cases. TFE3, CA9, Melan A and HMB45 were negative in all cases. SDHB retained expression. NGS demonstrated MTOR mutations in all cases, and TSC2 mutation in 2 cases. Conclusions: EVT is a rarely oncocytic renal tumor with unique morphology, immunohistochemical phenotype, molecular profile and an indolent behavior. Recognition of the characteristics of this novel but rare entity will allow for better classification of renal tumors.
Biomarkers, Tumor/metabolism* ; Carcinoma, Renal Cell/pathology* ; Female ; Humans ; Kidney/pathology* ; Kidney Neoplasms/pathology* ; Male ; Retrospective Studies ; TOR Serine-Threonine Kinases/genetics*