This study was aimed at investigating the immunoregulatory function of Mycobacterium tuberculosis Rv3641c gene in modulating host type Ⅰ interferon responses.The shuttle plasmid pMV261 was used to construct Rv3641c overexpression recombinant Mycobacterium smegmatis,and the biological characteristics of the recombinant bacteria were analyzed to explore the effect of Rv3641c on the growth curve,colony morphology and stress resistance of Mycobacterium.Subsequently,RAW264.7 cells were infected with Rv3641c overexpressing Mycobacterium smegmatis,and the transcriptional expression of genes related to the inhibition of type I inter-feron pathway was determined by RT-PCR.The expression level of IFN-βprotein was determined by ELISA,and the intracellular sur-vival level was determined.As a result,the recombinant rMS::pMV261-Rv3641c was successfully constructed.The results of biologi-cal characteristics analysis showed that Rv3641c did not affect the growth of mycobacteria,but significantly changed the colony mor-phology of mycobacteria and improved its resistance to H2O2.The results of recombinant bacteria infection experiments showed that Rv3641c significantly down-regulated the transcription levels of IFN-α,IFN-βand downstream ISGs genes CXCL10,IFIT2 and IL-1β in host cells,and Rv3641c significantly down-regulated the transcription levels of IFN-α,IFN-βand downstream ISGs genes CXCL10,IFIT2 and IL-1βin host cells.The results of intracellular colonization experiments showed that the intracellular mycobacte-ria in the overexpression recombinant bacteria infection group were significantly higher than those in the empty vector group,indicat-ing that Rv3641c could promote the intracellular surviv al of mycobacteria.In summary,the Rv3641c gene of M.tuberculosis can inhibit the host type I interferon response and promote the intracellular survival of M.tuberculosis,which provides a new idea for further explor-ing the immune escape function of M.tuberculosis and the discovery of new targets for anti-tuberculosis drugs.

Objective To explore the diagnostic value of mediastinal lymph nodes CT image features in pulmonary sarcoidosis.Methods The imageologic data of the patients with pulmonary sarcoidosis(pulmonary sarcoidosis group)and lung cancer complicating mediastinal lymph node metastasis(lung cancer group)con-firmed by EBUS-TBNA in this hospital from June 2015 to November 2023 were analyzed retrospectively.The chest plain scan CT and enhanced scan CT were performed in all cases,and the imaging characteristics were compared between the two groups.The receiver operating characteristic(ROC)curve was drawn and the area under the curve(AUC)was calculated.The diagnostic value of CT imaging characteristics in pulmonary sar-coidosis was analyzed.Results The proportion of female patients in the lung sarcoidosis group was signifi-cantly higher than that in the lung cancer group,while the age was smaller than that in the lung cancer group,and the differences were statistically significant(P＜0.05).The number of mediastinal lymph nodes,location,short diameter and CT enhancement value in the pulmonary sarcoidosis group had statistical difference(P＜0.05).The ROC curve analysis showed that AUC of lymph node short diameter reciprocal,CT enhancement value and position in detection alone were 0.586,0.785 and 0.505 respectively,and AUC of the three combined reciprocal was the highest(0.789).Conclusion The lymph node short diameter,CT enhancement value and po-sition have certain value in clinical diagnosis of pulmonary sarcoidosis and the 3-indicator combination could increase the diagnostic efficiency of pulmonary sarcoidosis.

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.

OBJECTIVE: To explore the application effect of grid locator in hip arthroscopy for the treatment of femoral acetabular impingement (FAI). METHODS: Total of 50 patients of FAI were treated by arthroscopic hip joint surgery for from January 2020 to January 2021, and were divided into two groups according to intraoperative positioning methods. Among them, 27 cases in the positioner group were treated by hip arthroscopy assisted by grid positioner including 10 males and 17 females with a mean age of (35.91±9.92) years old. In the non-locator group, 23 cases were treated with hip arthroscopy by positioning puncture according to the operator's experience including 12 males and 11 females with a mean age of (36.01±11.03) years old. Intraoperative fluoroscopy times, puncture time, adjusted puncture times and operation time of two groups were compared. The α Angle and lateral central edge(LCE) angle of hip joint were measured and compared before and after operation. Four evaluation indexes were recorded and compared, including pain visual analogue scale(VAS), hip Harris score, non-inflammatory hip joint score (NAHS), hip joint activities of daily living (HOS-ADL). RESULTS: All patients were followed up for 6 to 12 months with an average of (18.69±3.72) months. The α angle and LCE angle of hip joint at 1 month after operation were decreased in both groups(P<0.05), but there was no significant difference between groups(P>0.05). VAS, hip Harris score, NAHS and HOS-ADL score after operation were higher than those before operation(P<0.05), but there was no statistical significance between groups (P>0.05). Intraoperative fluoroscopy times(6.04±1.13), puncture time(13.19±3.52) min, puncture adjustment times(4.59±1.55) and operation time(48.28±3.38) min in the positioner group were less (shorter) than those of (13.43±2.56), (22.39±2.93) min, (10.43±3.33), (62.25±5.73) min in the non-positioner group(P<0.05). No postoperative complications occurred in both groups, and the pain was significantly relieved. CONCLUSION The application of hip arthroscopy in the treatment of femoral acetabular impingement sign can obtain good postoperative results. Compared with the traditional positioning method, the grid locator can improve the accuracy of skin positioning point, shorten the puncture time, reduce the number of fluoroscopy, and improve the efficiency of surgical puncture.
Humans ; Male ; Female ; Arthroscopy/instrumentation* ; Femoracetabular Impingement/physiopathology* ; Adult ; Middle Aged ; Hip Joint/surgery*

PURPOSE: We carried out the study aiming to explore and analyze the risk factors, the distribution of pathogenic bacteria, and their antibiotic-resistance characteristics influencing the occurrence of surgical site infection (SSI), to provide valuable assistance for reducing the incidence of SSI after traumatic fracture surgery. METHODS: A retrospective case-control study enrolling 3978 participants from January 2015 to December 2019 receiving surgical treatment for traumatic fractures was conducted at Tangdu Hospital of Air Force Medical University. Baseline data, demographic characteristics, lifestyles, variables related to surgical treatment, and pathogen culture were harvested and analyzed. Univariate analyses and multivariate logistic regression analyses were used to reveal the independent risk factors of SSI. A bacterial distribution histogram and drug-sensitive heat map were drawn to describe the pathogenic characteristics. RESULTS: Included 3978 patients 138 of them developed SSI with an incidence rate of 3.47% postoperatively. By logistic regression analysis, we found that variables such as gender (males) (odds ratio (OR) = 2.012, 95% confidence interval (CI): 1.235 - 3.278, p = 0.005), diabetes mellitus (OR = 5.848, 95% CI: 3.513 - 9.736, p < 0.001), hypoproteinemia (OR = 3.400, 95% CI: 1.280 - 9.031, p = 0.014), underlying disease (OR = 5.398, 95% CI: 2.343 - 12.438, p < 0.001), hormonotherapy (OR = 11.718, 95% CI: 6.269 - 21.903, p < 0.001), open fracture (OR = 29.377, 95% CI: 9.944 - 86.784, p < 0.001), and intraoperative transfusion (OR = 2.664, 95% CI: 1.572 - 4.515, p < 0.001) were independent risk factors for SSI, while, aged over 59 years (OR = 0.132, 95% CI: 0.059 - 0.296, p < 0.001), prophylactic antibiotics use (OR = 0.082, 95% CI: 0.042 - 0.164, p < 0.001) and vacuum sealing drainage use (OR = 0.036, 95% CI: 0.010 - 0.129, p < 0.001) were protective factors. Pathogens results showed that 301 strains of 38 species of bacteria were harvested, among which 178 (59.1%) strains were Gram-positive bacteria, and 123 (40.9%) strains were Gram-negative bacteria. Staphylococcus aureus (108, 60.7%) and Enterobacter cloacae (38, 30.9%) accounted for the largest proportion. The susceptibility of Gram-positive bacteria to Vancomycin and Linezolid was almost 100%. The susceptibility of Gram-negative bacteria to Imipenem, Amikacin, and Meropenem exceeded 73%. CONCLUSION Orthopedic surgeons need to develop appropriate surgical plans based on the risk factors and protective factors associated with postoperative SSI to reduce its occurrence. Meanwhile, it is recommended to strengthen blood glucose control in the early stage of admission and for surgeons to be cautious and scientific when choosing antibiotic therapy in clinical practice.
Humans ; Surgical Wound Infection/epidemiology* ; Male ; Female ; Risk Factors ; Retrospective Studies ; Middle Aged ; Adult ; Case-Control Studies ; Fractures, Bone/surgery* ; Aged ; Drug Resistance, Bacterial ; Logistic Models ; Anti-Bacterial Agents/therapeutic use* ; Incidence ; Bacteria/drug effects*

This study was aimed at investigating the immunoregulatory function of Mycobacterium tuberculosis Rv3641c gene in modulating host type Ⅰ interferon responses.The shuttle plasmid pMV261 was used to construct Rv3641c overexpression recombinant Mycobacterium smegmatis,and the biological characteristics of the recombinant bacteria were analyzed to explore the effect of Rv3641c on the growth curve,colony morphology and stress resistance of Mycobacterium.Subsequently,RAW264.7 cells were infected with Rv3641c overexpressing Mycobacterium smegmatis,and the transcriptional expression of genes related to the inhibition of type I inter-feron pathway was determined by RT-PCR.The expression level of IFN-βprotein was determined by ELISA,and the intracellular sur-vival level was determined.As a result,the recombinant rMS::pMV261-Rv3641c was successfully constructed.The results of biologi-cal characteristics analysis showed that Rv3641c did not affect the growth of mycobacteria,but significantly changed the colony mor-phology of mycobacteria and improved its resistance to H2O2.The results of recombinant bacteria infection experiments showed that Rv3641c significantly down-regulated the transcription levels of IFN-α,IFN-βand downstream ISGs genes CXCL10,IFIT2 and IL-1β in host cells,and Rv3641c significantly down-regulated the transcription levels of IFN-α,IFN-βand downstream ISGs genes CXCL10,IFIT2 and IL-1βin host cells.The results of intracellular colonization experiments showed that the intracellular mycobacte-ria in the overexpression recombinant bacteria infection group were significantly higher than those in the empty vector group,indicat-ing that Rv3641c could promote the intracellular surviv al of mycobacteria.In summary,the Rv3641c gene of M.tuberculosis can inhibit the host type I interferon response and promote the intracellular survival of M.tuberculosis,which provides a new idea for further explor-ing the immune escape function of M.tuberculosis and the discovery of new targets for anti-tuberculosis drugs.

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 quantitatively analyze the impact of environmental hygiene on the occurrence of health-care-associated infections(HAI).Methods Monitoring data of HAI and environmental hygiene from a tertiary first-class hospital from January 2018 to December 2022 were collected,and the impact of environmental bacterial colony forming unit(CFU)on the occurrence of HAI was analyzed by a time-series generalized additive model.Results The single-contamination model showed a significant positive correlation between HAI and staff's hand bacterial CFU(β1=0.009,P=0.012).For an increase of 1 interquartile range(IQR)in the monthly mean CFU per dish(MCFU/Dish)of staffs'hand,the incidence of HAI increased by 13.28％(95％CI:2.82％-24.81％).Subgroup and lag effect analysis showed that when the monthly MCFU/Dish(after hand disinfection)of staffs'hand in-creased by one IQR,the excess risk(ER)of HAI for the month(lag0)was 16.26％(95％CI:15.45％-17.09％).In the multi-contamination model,the correlation between surface contamination and HAI was also statistically sig-nificant.Conclusion There is a significant correlation between hospital environmental hygiene and the occurrence of HAI.

Lipopolysaccharides (LPS) are major outer membrane components of Gram-negative bacteria. Unlike most Gram-negative bacteria, Acinetobacter baumannii can still survive and acquire polymyxin resistance after complete loss of LPS. Previous studies of LPS-deficient Acinetobacter baumannii mostly focused on LPS-deficient strains induced by polymyxin, whose background was complex and unstable. To investigate LPS loss-mediated polymyxin resistant-Acinetobacter baumannii, this study constructed a stable and clear background LPS-deficient strain by knocking out lpxC gene in Acinetobacter baumannii ATCC 19606 with CIRSPR/Cas9, and then studied the phenotypic changes of the lpxC-deficient strain including morphology, growth rate, antibiotic susceptibility, virulence, membrane permeability, and membrane potential. Animal experiments were approved by the Animal Care and Welfare Committee Institute of Medicinal Biotechnology, CAMS and PUMC (approval number: IMB-20240119D₉). The results indicated that the lpxC gene of Acinetobacter baumannii ATCC 19606 was successfully knocked out. After losing the lpxC, the strain underwent the morphological change from rod-shaped to spherical. Furthermore, it leads to reduced growth rate, enhanced membrane permeability, decreased membrane potential, lower virulence, and increased antibiotic susceptibility to β-lactams, quinolones, aminoglycosides, macrolides, glycopeptides. The lpxC deletion results in significant changes in membrane homeostasis and adaptability of Acinetobacter baumannii. Understanding the phenotypic changes of colistin-resistant Acinetobacter baumannii mediated by LPS loss is useful for exploring the resistance mechanism of Acinetobacter baumannii and developing new therapeutic strategies.

Objective To investigate the neuroprotective effect of 7,8-dihydroxyflavone(7,8-DHF)on cerebral hemorrhage in mice by regulating the tyrosine kinase receptor B(TrkB)/brain derived neurotrophic factor(BDNF)signal pathway.Methods C57BL/6 mice were injected with bacterial collagenase V Ⅱ to establish cerebral hemorrhage model.The mice were randomly grouped into model group,control group(5 mg·kg-1 7,8-DHF),experimental group(1 mg·kg-1 K252a),and combined group(5 mg·kg-1 7,8-DHF+1 mg·kg-1 K252a),mice injected with normal saline were used as sham-operation group,with 10 mice in each group.After the treatment,the mice were scored for neurological function by Garcia method,brain water contents of the brain tissue were detected by the dry and wet weight method,the blood brain barrier permeability was examined using the Evans blue method,the neuronal apoptosis was detected by TUNEL method,and the protein expression levels of TrkB,phosphorylated TrkB(p-TrkB)and BDNF were detected by Western blot.Results The neurological function scores of control,experimental,combined,model and sham-operation groups were(15.47±1.55),(7.23±0.73),(10.55±1.06),(10.45±1.05)and(16.12±1.62)points;the brain water contents were(62.88±2.19)％,(83.77±3.11)％,(72.71±2.59)％,(72.88±2.61)％and(59.64±2.06)％;the Evans blue contents were(3.26±0.36),(16.23±1.63),(8.78±0.88),(9.47±0.95)and(1.02±0.11)μg·g-1;neuronal apoptosis rates were(9.82±0.99)％,(39.88±3.99)％,(22.15±2.24)％,(25.71±2.58)％and(6.46±0.65)％;p-TrkB/TrkB ratios were 1.01±0.11,0.21±0.03,0.48±0.05,0.49±0.05 and 1.03±0.11;the protein expression levels of BDNF were 1.15±0.12,0.18±0.02,0.46±0.05,0.42±0.05 and 1.18±0.12,respectively.The above indexes of sham-operation,control and experimental groups were compared with those of model group,and the above indexes of control and experimental groups were compared with those of combined group,the differences were statistically significant(all P＜0.05).Conclusion 7,8-DHF has neuroprotective effect on mice with intracerebral hemorrhage,and its mechanism may be related to the activation of TrkB/BDNF signal pathway.