Locomotion, a fundamental motor function encompassing various forms such as swimming, walking, running, and flying, is essential for animal survival and adaptation. The mesencephalic locomotor region (MLR), located at the midbrain-hindbrain junction, is a conserved brain area critical for controlling locomotion. This review highlights recent advances in understanding the MLR’s structure and function across species, from lampreys to mammals and birds, with a particular focus on insights gained from optogenetic studies in mammals. The goal is to uncover universal strategies for MLR-mediated locomotor control. Electrical stimulation of the MLR in species such as lampreys, salamanders, cats, and mice initiates locomotion and modulates speed and patterns. For example, in lampreys, MLR stimulation induces swimming, with increased intensity or frequency enhancing propulsive force. Similarly, in salamanders, graded stimulation transitions locomotor outputs from walking to swimming. Histochemical studies reveal that effective MLR stimulation sites colocalize with cholinergic neurons, suggesting a conserved neurochemical basis for locomotion control. In mammals, the MLR comprises two key nuclei: the cuneiform nucleus (CnF) and the pedunculopontine nucleus (PPN). Both nuclei contain glutamatergic and GABAergic neurons, with the PPN additionally housing cholinergic neurons. Optogenetic studies in mice by selectively activating glutamatergic neurons have demonstrated that the CnF and PPN play distinct roles in motor control: the CnF drives rapid escape behaviors, while the PPN regulates slower, exploratory movements. This functional specialization within the MLR allows animals to adapt their locomotion patterns and speed in response to environmental demands and behavioral objectives. Similar to findings in lampreys, the CnF and PPN in mice transmit motor commands to spinal effector circuits by modulating the activity of brainstem reticular formation neurons. However, they achieve this through distinct reticulospinal pathways, enabling the generation of specific behaviors. Further insights from monosynaptic rabies viral tracing reveal that the CnF and PPN integrate inputs from diverse brain regions to produce context-appropriate behaviors. For instance, glutamatergic neurons in the PPN receive signals from other midbrain structures, the basal ganglia, and medullary nuclei, whereas glutamatergic neurons in the CnF rarely receive inputs from the basal ganglia but instead are strongly influenced by the periaqueductal grey and inferior colliculus within the midbrain. These differential connectivity patterns underscore the specialized roles of the CnF and PPN in motor control, highlighting their unique contributions to coordinating locomotion. Birds exhibit exceptional flight capabilities, yet the avian MLR remains poorly understood. Comparative studies suggest that the pedunculopontine tegmental nucleus (PPTg) in birds is homologous to the mammalian PPN, which contains cholinergic neurons, while the intercollicular nucleus (ICo) or nucleus isthmi pars magnocellularis (ImC) may correspond to the CnF. These findings provide important clues for identifying the avian MLR and elucidating its role in flight control. However, functional validation through targeted experiments is urgently needed to confirm these hypotheses. Optogenetics and other advanced techniques in mice have greatly advanced MLR research, enabling precise manipulation of specific neuronal populations. Future studies should extend these methods to other species, particularly birds, to explore unique locomotor adaptations. Comparative analyses of MLR structure and function across species will deepen our understanding of the conserved and evolved features of motor control, revealing fundamental principles of locomotion regulation throughout evolution. By integrating findings from diverse species, we can uncover how the MLR has been adapted to meet the locomotor demands of different environments, from aquatic to aerial habitats.

Umbilical cord mesenchymal stem cells (UC-MSCs) have been widely used in regenerative medicine, but there is limited research on the stability of UC-MSCs formulation during production. This study aims to assess the stability of the cell stock solution and intermediate product throughout the production process, as well as the final product following reconstitution, in order to offer guidance for the manufacturing process and serve as a reference for formulation reconstitution methods. Three batches of cell formulation were produced and stored under low temperature (2-8 ℃) and room temperature (20-26 ℃) during cell stock solution and intermediate product stages. The storage time intervals for cell stock solution were 0, 2, 4, and 6 h, while for intermediate products, the intervals were 0, 1, 2, and 3 h. The evaluation items included visual inspection, viable cell concentration, cell viability, cell surface markers, lymphocyte proliferation inhibition rate, and sterility. Additionally, dilution and culture stability studies were performed after reconstitution of the cell product. The reconstitution diluents included 0.9% sodium chloride injection, 0.9% sodium chloride injection + 1% human serum albumin, and 0.9% sodium chloride injection + 2% human serum albumin, with dilution ratios of 10-fold and 40-fold. The storage time intervals after dilution were 0, 1, 2, 3, and 4 h. The reconstitution culture media included DMEM medium, DMEM + 2% platelet lysate, 0.9% sodium chloride injection, and 0.9% sodium chloride injection + 1% human serum albumin, and the culture duration was 24 h. The evaluation items were viable cell concentration and cell viability. The results showed that the cell stock solution remained stable for up to 6 h under both low temperature (2-8 ℃) and room temperature (20-26 ℃) conditions, while the intermediate product remained stable for up to 3 h under the same conditions. After formulation reconstitution, using sodium chloride injection diluted with 1% or 2% human serum albumin maintained a viability of over 80% within 4 h. It was observed that different dilution factors had an impact on cell viability. After formulation reconstitution, cultivation in medium with 2% platelet lysate resulted in a cell viability of over 80% after 24 h. In conclusion, the stability of cell stock solution within 6 h and intermediate product within 3 h meets the requirements. The addition of 1% or 2% human serum albumin in the reconstitution diluent can better protect the post-reconstitution cell viability.

Objective To study the application effect of quality control circle(QCC)in reducing the dissatisfaction rate of physical examination clients in health management center.Methods To establish QCC,selected the health check-up popula-tion in our hospital in September-2019 and March-2020,through the questionnaire investigation and analysis,compare the dis-satisfaction of the clients before and after the quality control circle.Results After carrying out QCC activities,the dissatisfaction of physical examination clients was significantly lower than that before QCC,and the difference was statistically significant(P＜0.05).Conclusion The activities of QCC in the health management center can effectively improve the quality of the physical examination work and reduce the dissatisfaction of the customers in the physical examination.It is of great significance to the health management.

Objective To explore the effect of emodin on inflammatory response in preeclampsia(PE)rats by regulating the AMP activated protein kinase(AMPK)/thioredoxin-interacting protein(TXNIP)/NOD-like receptor pyrin domain-containing protein 3(NLRP3)signaling pathway.Methods PE rat model was established by subcutaneous injection of L-arginine methyl ester(100 mg·kg-1).Sixty female rats were randomly divided into control group,model group,emodin group(40 mg·kg-1 emodin),Compound B10 group(100 mg·kg-1 Compound B10),emodin+Compound B10 group(40 mg·kg-1 emodin+100 mg·kg-1 Compound B10),with 12 rats in each group.The control group and the model group were intraperitoneally injected with the same amount of 0.9％NaCl.The 24 h urine was collected,and the total urinary protein content was determined by Coomassie brilliant blue method.The protein levels of AMPK/TXNIP/NLRP3 signaling pathway were detected by Western blot.Results The total urinary protein levels of control group,model group,emodin group,Compound B10 group and emodin+Compound B10 group were(54.34±6.26),(136.37±15.43),(76.38±8.61),(215.39±25.14)and(110.93±13.92)g·L-1,respectively;urine volume were(10.59±0.92),(15.38±1.49),(11.51±1.13),(21.49±2.50)and(14.71±1.49)mL,respectively;AMPK protein levels were 0.63±0.06,1.57±0.18,0.81±0.09,2.34±0.23 and 1.38±0.15,respectively;TXNIP protein levels were 0.33±0.04,0.79±0.08,0.49±0.10,1.13±0.12 and 0.82±0.09,respectively;NLRP3 protein levels were 0.46±0.05,0.83±0.09,0.56±0.07,1.25±0.14 and 0.78±0.08,respectively.The above indexes:Model group was compared with control group,emodin group and Compound B10 group,emodin+Compound B10 group was compared with emodin group,the differences were statistically significant(all P＜0.05).Conclusion Emodin may alleviate inflammatory reaction in PE rats by inhibiting AMPK/TXNIP/NLRP3 signal axis,thereby improving placental injury.

Objective To analyze the prognostic significance and biological effects of cytochrome P450 family 27 subfamily A member 1(CYP27A1)in hepatocellular carcinoma(HCC),and to preliminarily explore its molecular mechanism of regulating the malignant growth of HCC.Methods The Cance Genome Atlas(TCGA)database was used to analyze the expression level of CYP27A1 and its prognostic effect on HCC patients.The samples were divided into CYP27A1 high-expression group(n=170)and low-expression group(n=170)based on the median expression of CYP27A1 in HCC,gene set enrichment analysis(GSEA)was performed to investigate gene sets associated with CYP27A1 expression.The subcellular localization of CYP27A1 was detected by immunofluorescence staining and search database.The over-expression plasmid of CYP27A1 was constructed and then transfected into the HCC cells MHCC-97H and HCCLM3 cell lines,including two groups,namely control group(transfecting empty vector)and CYP27A1 over-expression group(transfecting CYP27A1 over-expressed vector).CCK-8,flow cytometer,and reactive oxygen species(ROS)fluorescence probe were applied to detect the effects of CYP27A1 over-expression on cell viability,apoptosis and ROS levels in HCC cells.Combining bioinformatics to analyze the correlation between CYP27A1 and the expression of ROS generation-related genes and HCC proliferation-related genes.Results Compared with the normal liver tissue,the expression level of CYP27A1 mRNA in HCC tissue was significantly reduced(P<0.01).The expression of CYP27A1 was significantly correlated with sex,T stage,tumor grade and tumor stage of HCC patients(P<0.05).Compared to the CYP27A1 high-expression group,patients in CYP27A1 low-expression group had lower survival rate(P<0.01).GSEA enrichment analysis revealed that the levels of HCC stem cell-related gene clusters and HCC proliferation gene clusters were remarkably increased in CYP27A1 low-expression group.The immunofluorescence showed that CYP27A1 was mainly located in nucleus in MHCC-97H and HCCLM3,whereas CYP27A1 was mainly located in mitochondria in HepG2.CYP27A1 over-expression attenuated cell viability(P<0.01),and reduced the ROS levels(P<0.05),whereas it had no effects on the apoptosis in HCC cells(P>0.05).The expression of CYP27A1 and the expression of inhibiting ROS generation-related genes were positively correlated(P<0.05),while the expression of inhibiting ROS generation-related genes and the expression of HCC proliferation-related genes were negatively correlated(P<0.05).Conclusions The expression of CYP27A1 was decreased in HCC,and down-regulated CYP27A1 promoted cell growth by enhancing ROS generation,although the precise mechanism requires future educidation.

Further evidence is needed to explore the impact of high-altitude environments on the neurologic function of neonates.Non-invasive techniques such as cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography can provide data on cerebral oxygenation and brain electrical activity.This study will conduct multiple cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography monitoring sessions at various time points within the first 3 days postpartum for healthy full-term neonates at different altitudes.The obtained data on cerebral oxygenation and brain electrical activity will be compared between different altitudes,and corresponding reference ranges will be established.The study involves 6 participating centers in the Chinese High Altitude Neonatal Medicine Alliance,with altitude gradients divided into 4 categories:800 m,1 900 m,2 400 m,and 3 500 m,with an anticipated sample size of 170 neonates per altitude gradient.This multicenter prospective cohort study aims to provide evidence supporting the impact of high-altitude environments on early brain function and metabolism in neonates.[Chinese Journal of Contemporary Pediatrics,2024,26(4):403-409]

Objective To investigate the amplitude-integrated electroencephalography(aEEG)monitoring results of hospitalized neonates in plateau areas.Methods A retrospective analysis was conducted on 5 945 neonates who were admitted to the Department of Neonatology,Kunming Children's Hospital,and received aEEG monitoring from January 2020 to December 2022.According to the aEEG monitoring results,they were divided into a normal aEEG group and an abnormal aEEG group.The incidence rate of aEEG abnormalities was analyzed in neonates with various systemic diseases,as well as the manifestations of aEEG abnormalities and the consistency between aEEG abnormalities and clinical abnormalities.Results Among the 5 945 neonates,the aEEG abnormality rate was 19.28%(1 146/5 945),with an abnormality rate of 29.58%(906/3 063)in critically ill neonates and 8.33%(240/2 882)in non-critically ill neonates(P<0.05).The children with inherited metabolic diseases showed the highest aEEG abnormality rate of 60.77%(79/130),followed by those with central nervous system disorders[42.22%(76/180)]and preterm infants[35.53%(108/304)].Compared with the normal aEEG group,the abnormal aEEG group had significantly lower age and gestational age,as well as a significantly lower birth weight of preterm infants(P<0.05).Among the 1 146 neonates with aEEG abnormalities,the main types of aEEG abnormalities were sleep cycle disorders in 597 neonates(52.09%),background activity abnormalities in 294 neonates(25.65%),and epileptiform activity in 255 neonates(22.25%),and there were 902 neonates(78.71%)with abnormal clinical manifestations.The sensitivity and specificity of aEEG monitoring for brain function abnormalities were 33.51%and 92.50%,respectively.Conclusions In plateau areas,there is a relatively high rate of aEEG abnormalities among hospitalized neonates,particularly in critically ill neonates and those with smaller gestational ages and younger ages,suggesting a high risk of brain injury.Therefore,routine aEEG monitoring for the hospitalized neonates can help with the early detection of brain function abnormalities,the decision-making in treatment,and the formulation of brain protection strategies.

Objective To establish the pharmacokinetic model of linezolid in neonates,and to optimize the administration regimen. Methods A prospective study was conducted among 64 neonates with sepsis who received linezolid as anti-infective therapy,and liquid chromatography-tandem mass spectrometry was used to measure the plasma concentration of the drug. Clinical data were collected,and nonlinear mixed effects modeling was used to establish a population pharmacokinetic (PPK) model. Monte Carlo simulation and evaluation was performed for the optimal administration regimen of children with different features. Results The pharmacokinetic properties of linezolid in neonates could be described by a single-compartment model with primary elimination,and the population typical values for apparent volume of distribution and clearance rate were 0.79 L and 0.34 L/h,respectively. The results of goodness of fit,visualization verification,and the Bootstrap method showed that the model was robust with reliable results of parameter estimation and prediction. Monte Carlo simulation results showed that the optimal administration regimen for linezolid in neonates was as follows:6 mg/kg,q8h,at 28 weeks of gestational age (GA);8 mg/kg,q8h,at 32 weeks of GA;9 mg/kg,q8h,at 34-37 weeks of GA;11 mg/kg,q8h,at 40 weeks of GA. Conclusions The PPK model established in this study can provide a reference for individual administration of linezolid in neonates. GA and body weight at the time of administration are significant influencing factors for the clearance rate of linezolid in neonates.

Objective To understand the epidemiological and clinical characteristics of healthcare-associated infec-tion(HAI)in neonates with different gestational ages and birth weights,and provide guidance for personalized cli-nical diagnosis and treatment.Methods According to the inclusion and exclusion criteria,240 neonates with HAI in the neonatal intensive care unit(NICU)of a hospital in Handan City from January 2018 to December 2022 were selected as the study group,720 neonates without HAI were selected as the control group based on systematic sam-pling method with a ratio of 1∶3.The incidence of HAI,distribution characteristics of infection site,pathogenic features of HAI,as well as the effect of different delivery modes on HAI in neonates with different gestational ages and birth weights were analyzed.Results Neonates with gestational age＜28 weeks and birth weight＜1 000 g had the highest incidence of HAI,which were 19.48％and 20.41％,respectively.Among neonates with gestational age＜28 weeks,unidentified site infection were the most(37.50％),while in all gestational age groups within 28-36+6 weeks,bloodstream infection(BSI)and respiratory system infection were predominant.For neonates with gestational age ≥37 weeks,BSI and unidentified site infection occurred frequently.Among neonates in all weight groups,BSI was the most frequent,followed by respiratory system infection.Pathogens from different sites of in-fections in neonates with different gestational ages and birth weights varied.Among neonates with gestational age of 28-31+6 weeks and birth weight of 1 000-1 499 g,the constituent of birth modes showed statistically significant difference between neonates with and without HAI(both P＜0.05).Conclusion Epidemiological and clinical chara-cteristics of HAI in neonates with different gestational ages and birth weights are different.For the prevention and control of HAI,individualized diagnosis and treatment plans should be developed to achieve precise prevention and control,reduce the incidence of HAI,and improve the overall treatment level of neonates.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.