Objective : To investigate the drug resistance and pathogenicity of six clinical isolates of Klebsiella pneu- moniae (Kp) ，and to provide a basis for prevention and treatment of Kp infection． Methods : The six strains from different hospitals were isolated ，cultured ，and identified by species-specific gene khe． Their whole genome se- quences (WGS) were obtained using next-generation sequencing technology (NGS) ．Based on the WGS，the cap- sular serotypes，sequence types (ST) and drug-resistance genes of six strains were identified．The capsular sero- type genes and virulence genes were validated or identified using PCR. Broth microdilution tests were conducted to validate their drug susceptibility，and mice were challenged with Kp aerosols by MicroSprayer aerosolizer to evaluate their pathogenicity. Results : The six strains were all serotype K2 but belonged to four ST types ( ST14 ，ST65， ST700，and ST86) ，and collectively carried six virulence genes and 23 drug-resistance genes．All the six strains were resistant to ampicillin，but only one strain was multidrug-resistant．Four strains exhibited high mucoid charac- teristics．Five strains could cause mortality in mice，which were preliminary identified as high virulence strains. Conclusion For the six Kp clinical isolates from different sources，only one strain named NY 13294 is both multi- drug-resistant and highly virulent，and other four highly virulent strains are resistant to one or two types of antibiot- ics.

Objective To establish two golden hamster models infected with hypervirulent Klebsiella pneumoniae via aerosolized intratracheal(i.t.)and intranasal(i.n.)inoculation,and compare their properties.Methods Golden hamsters of 4 to 5 weeks old were exposed to K.pneumoniae NTUH-K2044 via i.t.route and i.n.route respectively.The survival of these golden hamsters was observed and recorded within 14 days of infection before the 50%lethal dose(LD50),survival rate,bacterial respiratory deposition rate,lung bacterial load and histopathology of the infected golden hamsters in the two groups were detected.Results The LD50 of the i.t.route(3×104 CFU)was lower than that of the i.n.route(7×105 CFU)in golden hamsters.After 4×106 CFU NTUH-K2044 infection,the golden hamsters in the i.t.group had 96.46%of the bacteria deposited and colonized in the lung,developed lobar pneumonia and died without exception within 4 days of infection,while those in the i.n.group had 95.62%of the bacteria deposited in the mouth and nose initially before the bacteria moved down to the trachea for colonization and were cleared out gradually.This group mainly acquired bronchopneumonia with relatively mild lung lesions,with a 14-day survival rate of 70%.Conclusion Inoculation routes can make a difference to the disease type of respiratory tract infections in animal models.The i.t.route mainly causes lobar pneumonia with severe lung lesions,while the i.n.route leads to bronchopneumonia with mild lung lesions.The two animal models established above may be utilized for pathogenesis investigation and treatment efficacy evaluation of Klebsiella pneumoniae.

Objective To establish an inhalation infection pneumonia model of C57BL/6J mice with highly virulent and multi-drug resistant Pseudomonas aeruginosa(PA)strain F291007,and to study the microbiological,pathological and immunological characteristics of this model.Methods The strain F291007 was isolated and identified before the bacterial suspension was administered to the mice via aerosolized intratracheal inoculation to establish the pneumonia infection model.In the course of infection,the conditions and survival of the mice were observed,and the bacterial loads,the histopathological states and the cytokine expression levels in the major organs were detected.Finally,three key cytokines were blocked to observe the survival of mice.Results The strain F291007 was isolated and identified.After lethal dose infection,all the mice died within 24 h.After sub-lethal dose infection,a large number of immune cells in the body were capable of phagocytosis and killing of invading pathogens,which was manifested as rapid clearance of bacteria in lungs and the exponential decrease of bacterial load with the passage of time.The pathological changes in lungs were most severe at 1 to 3 days but gradually recovered.After infection,interleukin-6(IL-6),IL-17A and tumor necrosis factor-α(TNF-α)in alveolar lavage fluid and serum were significantly increased at 1 to 3 days.After blocking of these three cytokines with specific antibodies,the survival rates of infected mice decreased significantly.Conclusion A mouse model of gradually-recovered pneumonia infection caused by PA inhalation has been established,suggesting that the first one to three days are critical to immune response after infection through multiple indicators.This mouse model can be used for research on the pathogenesis,immunoregulation and treatment evaluation of highly virulent and multi-drug resistant PA inhalation pneumonia infection.

Objective To construct a non-trace deletion mutant of exlA in Pseudomonas aeruginosa strain NY8755(NY8755ΔexlA)and investigate the basic characteristics of pore-forming toxin ExlA.Methods The NY8755ΔexlA was constructed using the secondary homologous recombination method.C57BL/6J female mice ages 6 to 8 weeks were infected with NY8755 and NY8755 ΔexlA via aerosolized intratraheal inoculation respectively.Within 7 days of infection,the survival and weight changes of the mice were observed and recorded before the proinflammatory cytokines in the bronchoal-veolar lavage fluid(BALF)of the infected mice in the two groups were detected.Results The sequencing results showed that NY8755 ΔexlA was constructed.After 1×107 CFU NY8755 and NY8755 ΔexlA were infected,all the mice in the wild-type strain group died within 48 hours,while those in the mutant strain group began to die after 48 hours,and 40%of them remained alive 7 days later.The weight of surviving mice in the mutant strain group decreased but recovered gradually.After 12 hours of infection,there were more bloody exudates(redder in color)in the BALF of the wild-type strain group than in the mutant strain group,and the contents of proinflammatory cytokines interleukin-1β(IL-1β)and interleukin-17A (IL-17A)were significantly different. Conclusion Pseudomonas aeruginosa pore-forming toxin ExlA is the key pathogenic virulence factor of the exlA-positive Pseudomonas aeruginosa,which can significantly affect the survival status of mice and cause obvious inflammation in mice. Very little information is available on the action mechanisms of ExlA. In this study, The NY8755ΔexlA and the C57BL/6J mouse models infected with NY8755 and NY8755ΔexlA have been constructed that may be used for the investigation of pathogenesis of exlA-positive Pseudomonas aeruginosa.

Objective:To investigate the changing trends in cardiac function following xenogeneic heterotopic heart transplantation of multi-gene edited pig hearts and assess the impact of recipient immune responses on donor heart, laying experimental groundwork for the clinical application of gene editing technology.Methods:On December 16, 2023, xenogeneic heterotopic heart transplantation was performed between pigs and rhesus monkeys. Functional status of the graft under post-transplantation load conditions and recipient immune indicators were observed.Results:The recipient monkeys survived for 40 days with satisfactory functionality of both donor and recipient hearts, and no hyperacute or acute immune rejection reactions were observed.Conclusion:Multi-gene editing technology provides potential for xenotransplantation, yet further exploration is needed for its clinical application.

Alternative splicing (AS) is an evolutionarily conserved mechanism that removes introns and ligates exons to generate mature messenger RNAs (mRNAs), extremely improving the richness of transcriptome and proteome. Both mammal hosts and pathogens require AS to maintain their life activities, and inherent physiological heterogeneity between mammals and pathogens makes them adopt different ways to perform AS. Mammals and fungi conduct a two-step transesterification reaction by spliceosomes to splice each individual mRNA (named cis -splicing). Parasites also use spliceosomes to splice, but this splicing can occur among different mRNAs (named trans -splicing). Bacteria and viruses directly hijack the host's splicing machinery to accomplish this process. Infection-related changes are reflected in the spliceosome behaviors and the characteristics of various splicing regulators (abundance, modification, distribution, movement speed, and conformation), which further radiate to alterations in the global splicing profiles. Genes with splicing changes are enriched in immune-, growth-, or metabolism-related pathways, highlighting approaches through which hosts crosstalk with pathogens. Based on these infection-specific regulators or AS events, several targeted agents have been developed to fight against pathogens. Here, we summarized recent findings in the field of infection-related splicing, including splicing mechanisms of pathogens and hosts, splicing regulation and aberrant AS events, as well as emerging targeted drugs. We aimed to systemically decode host-pathogen interactions from a perspective of splicing. We further discussed the current strategies of drug development, detection methods, analysis algorithms, and database construction, facilitating the annotation of infection-related splicing and the integration of AS with disease phenotype.
Animals ; Alternative Splicing/genetics* ; RNA Splicing ; Spliceosomes/metabolism* ; RNA, Messenger/metabolism* ; Communicable Diseases/genetics* ; Mammals/metabolism*

Objective:To explore the temporal and spatial distribution characteristics of reported incidence of schizophrenia in Ningbo from 2018 to 2022 and to provide a scientific basis for rational allocation of mental health resources and comprehensive prevention and treatment of schizophrenia.Methods:The reported incidence data of schizophrenia from 2018 to 2022 were collected from Ningbo's mental health information management system, and the reported incidence was calculated by township. The spatial correlation analysis and the spatiotemporal scan analysis were used to study the spatiotemporal distribution of schizophrenia.Results:The reported incidence of schizophrenia decreased from 2018 to 2022, with 4 133 new cases reported, and the annual average reported incidence was 9.76/100 000. Global and local spatial autocorrelation analysis showed positive spatial correlations and hot spots in 2018-2020. The space-time scan analysis showed an incidence cluster in Dongqiao Town, Haishu District, during 2018-2019. The RR was 2.46, and the log-likelihood ratio was 256.89. Conclusions:The reported incidence of schizophrenia in Ningbo has obvious temporal and spatial aggregation, and the high incidence area explored can provide clues for further research on the correlation between environmental factors and the incidence of schizophrenia and has certain guiding significance for the rational allocation of mental health resources in Ningbo.

Objective:To assess the efficacy of a minimally invasive technique for repairing tibial plateau bicondylar fractures utilizing the double reverse traction repositor.Methods:A retrospective analysis was performed of the data of 31 patients (Schatzker V 17 cases, Schatzker VI 14 cases) who had been admitted to trauma center of Shandong provincial hospital affiliated to Shandong first medical university for tibial plateau bicondylar fractures from January 2017 to January 2022. There were 21 males and 10 females, aged from 18 to 67 years (average, 32.4±6.5 years). The intervention strategy comprised the use of a double reverse traction repositor and was augmented by precise screw fixation. A comprehensive set of parameters were measured, including time interval between injury and operation, operation time, blood loss, hospital stay, fracture healing time, incision complications. Postoperative assessments were made immediately and at the 12-month mark, including the evaluation of articular step-off height, medial tibial plateau angle, and posterior tibial slope angle. The evaluation also included thTime interval between injury and operation ranged from 5 to 11 days, with an average of 6.1±1.3 days. The surgical procedures varied in length from 70 to 160 minutes, averaging at 109.2±15.6 minutes. The volume of blood loss was noted to be between 90 to 380 ml, averaging at 176.5±20.8 ml. Hospitalization spanned from 10 to 15 days, with an average stay of 12.2 ±0.8 days. Over a follow-up duration of 12 to 20 months, averaging at 13.5±1.1 months, all patients achieved fracture union within a period of 11 to 20 weeks, with an average time of 14.6±1.5 weeks. The postoperative articular step-off was recorded at 0.45±0.13 mm immediately after surgery and 0.58±0.21 mm at the one-year follow-up. Similarly, the medial tibial plateau angle and posterior tibial slope angle showed marginal changes from the immediate postoperative period to the 12-month evaluation. Knee joint mobility at the one-year mark ranged impressively from 0° to 135°, with an average of 125.6°±2.1°. Functional outcomes as reflected by Rasmussen scores ranged from 18 to 28 points, with an average of 25.4±1.7 points. Pain, as assessed by the VAS, had a low score range of 0 to 2 points, averaging at 0.7±0.2 points. Notably, there were no postoperative complications associated with the incisions, such as fat liquefaction, infection, skin necrosis, or exposure of internal fixations. Additionally, no cases of delayed union or fixation failure were observed. Six patients had traumatic arthritis 1 year after operation.Conclusion:The minimally invasive double reverse traction repositor technique for tibial plateau bicondylar fracture repair is effective, warranting its broader application in orthopedic surgery.

Blumea balsamifera belonging to Blumea of Compositae family is a perennial herb or subshrub ，which is the only source of Traditional Chinese medicine Aipian and ethnic medicine essential oil of B. balsamifera . B. balsamifera contains volatile oil，flavonoids，sesquiterpenoids，phenylpropanoids，etc.，and shows antibacterial ，anti-inflammatory，analgesic，treating burns and scalds，neuroprotective and antioxidant effects ，etc. In this paper ，the chemical constituents and pharmacological activities are summarized by reviewing the domestic and foreign research literatures ，and it is expected to provide a reference for the in-depth research and development and utilization of B. balsamifera .

Objective:To develop a model of stellate ganglion block (SGB) in mice and investigate the effect of SGB on cerebral cortical blood flow.Methods:Thirty clean-grade healthy male C57BL/6 mice, aged 8-9 weeks, weighing 23-27 g, were divided into 5 groups ( n=6 each) using a random number table method: control group (group C), left SGB group (group L), left normal saline group (group SL), right SGB group (group R) and right normal saline group (group SR). Group C received no intervention.SGB was performed with 0.25% ropivacaine 0.08 ml via percutaneous posterior approach in L and R groups, while the equal volume of normal saline 0.08 ml was given instead at the location of left and right stellate ganglion in SL and SR groups, respectively.The cerebral cortical blood flow was determined using laser speckle contrast imaging system before SGB (T 0) and at 10, 30, 60, 90 and 120 min after SGB (T 1-5). Results:Mice developed ptosis on the block side, indicating that the model of SGB was successfully developed in L and R groups.There was no significant difference in cerebral cortical blood flow at each time point among C, SL and SR groups ( P>0.05), and cerebral cortical blood flow on the block side decreased at T 1, began to increase at T 2, peaked at T 3, and decreased at T 5 which was still higher than that at T 0 in group L and group R ( P<0.01). Compared with C and SL groups, the left cerebral cortical blood flow was significantly decreased at T 1, 5 and increased at T 2-4 in group L ( P<0.01). Compared with C and SR groups, the right cerebral cortical blood flow was significantly decreased at T 1, 5 and increased at T 2-4 in group R ( P<0.01). There were no significant differences in cerebral cortical blood flow at each time point between group C and group SL and between group C and group RL ( P>0.05). Conclusions:The mouse model of SGB via percutaneous posterior approach is successfully developed.Unilateral SGB can affect cerebral cortical blood flow on the block side, which shows a transitory decrease followed by a sustained significant increase.