Objective:To develop a recombinant protein vaccine based on KPC-2, a drug resistance target in Klebsiella pneumoniae, and evaluate its immunogenicity, protective efficacy and mechanism in a mouse model of pneumonia. Methods:KPC-2 was expressed in Escherichia coli and purified using GST affinity chromatography. A recombinant protein vaccine was prepared with KPC-2 and used to immunize New Zealand rabbits through subcutaneous injection. Serum samples were isolated from cardiac blood and Protein G chromatography was used to purify polyclonal antibodies against KPC-2. Opsonophagocytic killing assay was used to assess the bactericidal activity of the polyclonal antibodies in vitro. Female BALB/c mice were immunized three times with the recombinant protein vaccine, and the titers of specific IgG antibodies in serum were measured by indirect ELISA. One week after the last vaccination, the mice were infected with Klebsiella pneumoniae strain SRT through tracheal intubation, and received a single intravenous dose of meropenem (0.1 mg) 1 h later. The protective efficacy of the KPC-2 recombinant protein vaccine was evaluated by comparing the survival rates, bacterial colonization and histopathological changes between vaccine group and adjuvant group as well as the survival rates between meropenem group and normal saline group. Moreover, the protective efficacy of polyclonal antibodies against KPC-2 was evaluated through passive immunization. Results:The level of specific IgG antibodies in serum was significantly higher in the vaccine group than in the adjuvant group ( t=4.325, P<0.05). The survival rate in the vaccine group was also higher than that of the adjuvant group [70% (7/10) vs 10% (1/10), P<0.05]. Furthermore, lung inflammation was less severe and bacterial burden was reduced in the vaccine group as compared with those of the control group ( t=3.127, P<0.05). Both active and passive vaccination strategies demonstrated strong protective efficacy against Klebsiella pneumoniae infection, and had a synergistic effect when used in combination with antibiotic therapy. The polyclonal antibodies against KPC-2 had bactericidal activity in vitro ( t=5.427, P<0.05). Conclusions:The prepared KPC-2 vaccine has better immunogenicity and protective efficacy. It can induce strong humoral immune responses. This study suggest that drug resistance target may be used as a candidate antigen for future vaccine development.

The cyclic GMP-AMP synthase(cGAS)-stimulator of interferon genes signaling pathway plays a central role in cells'ability to sense the presence of abnormal double-stranded DNA within the cytoplasm.Modulation of the function of the cytoplasmic DNA recognition receptor cGAS allows regulation of this signaling pathway.In recent years,research has identified protein post-translational modifications(PTMs),including phosphorylation,acetylation,ubiquitination,methylation,and SUMOylation,as having significant roles in regulating innate immune signaling pathways.This paper reviews how PTMs influence the function of cGAS and its downstream signaling pathways through various mechanisms.

Objective:To explore the mechanism of miR-15b-5p involving in depression-like behavior in Parkinson's disease (PD).Methods:(1) Eighteen C57BL/6N mice were randomly divided into PD group, intervention group and control group ( n=6). PD models in PD group were established by stereotaxically injecting 0.25 mg/kg rotenone into the right striatum; mice in the intervention group were injected with 0.25 mg/kg rotenone and miR-15b-5p inhibitor lentivirus, while mice in the control group were injected with equal volume of PBS. Four weeks after that, open field test and rotarod test were performed to evaluate the motor ability, and sucrose preference and forced swimming tests were performed to evaluate the depression-like behaviors. And then, proteins and miRNAs in the substantia nigra were extracted; real-time fluorescent quantitative reverse transcription PCR (qRT-PCR) was used to detect the miR-15b-5p expression,and Western blotting and immunofluorescent staining were used to detect the tyrosine hydroxylase (TH), brain-derived neurotrophic factor (BDNF), tropomyosin receptor kinase B (TrkB), and postsynaptic density protein 95 (PSD95) protein expressions. (2) The 100 nmol/L miR-15b-5p mimic/inhibitor and their negative control sequences were transfected into SH-SY5Y cells on 6-well plates (named miR-15b-5p mimic group, miR-15b-5p mimic control group, miR-15b-5p inhibitor group and miR-15b-5p inhibitor control group, respectively); 48 h after that, BDNF, TrkB and PSD95 protein expressions were detected by Western blotting and miR-15b-5p expression by qRT-PCR. (3) The 100 ng BDNF 3'-UTR wild-type or mutant luciferase reporter vector plasmids and 100 nmol/L miR-15b-5p mimic/inhibitor or their negative control sequences were co-transfected into SH-SY5Y cells on 24-well plates, and luciferase reporter activity assay was performed 48 h after co-transfection to detect the luciferase activity. Results:(1) Compared with the control group, the PD group had significantly reduced movement speed, shortened rotarod drop latency, decreased percentage of sucrose preference, and prolonged immobility time ( P<0.05); compared with the PD group, the intervention group had significantly increased movement speed, prolonged rotarod drop latency, increased percentage of sucrose preference, and shortened immobility time ( P<0.05). (2) Compared with the miR-15b-5p mimic control group, the miR-15b-5p mimic group had significantly increased miR-15b-5p expression, and decreased BDNF, TrkB and PSD95 protein expressions (100.00±5.75 vs. 66.79±5.90; 100.00±5.95 vs. 84.46±5.77; 100.00±7.02 vs. 80.43±3.25, P<0.05). Compared with the miR-15b-5p inhibitor control group, the miR-15b-5p inhibitor group had significantly decreased miR-15b-5p expression, and increased BDNF, TrkB and PSD95 expressions (100.00±6.81 vs. 119.90±5.66; 100.00±2.88 vs. 110.10±4.15; 100.00±2.19 vs. 124.60±11.69, P<0.05). Compared with the control group, PD group had significantly increased miR-15b-5p expression, and significantly decreased TH, BDNF, TrkB and PSD95 expressions and BDNF fluorescent intensity (100.00±9.20 vs. 63.60±12.80; 100.00±9.88 vs. 71.95±10.00; 100.00±5.16 vs. 70.37±8.43; 100.00±7.01 vs. 68.12±10.22; 100.00±12.99 vs. 48.23±12.58) in the substantia nigra ( P<0.05); compared with the PD group, the intervention group had significantly lower miR-15b-5p expression and increased TH, BDNF, TrkB and PSD95 expressions and BDNF fluorescent intensity (63.60±12.80 vs. 90.69±9.84; 71.95±10.00 vs. 93.31±4.50; 70.37±8.43 vs. 88.11±4.10; 68.12±10.22 vs. 89.59±5.93; 48.23±12.58 vs. 83.65±10.52) in the substantia nigra ( P<0.05). (3) Compared with the BDNF 3'-UTR wild-type+miR-15b-5p mimic control group, the BDNF 3'-UTR wild-type+miR-15b-5p mimic group had significantly decreased luciferase activity (100.00±5.07 vs. 90.59±1.75, P<0.05); compared with the BDNF 3'-UTR wild-type+miR-15b-5p inhibitor control group, the BDNF 3'-UTR wild-type+miR-15b-5p inhibitor group had significantly increased luciferase activity (100.00±5.08 vs. 152.20±31.87, P<0.05). Conclusion:MiR-15b-5p is involved in depression-like behavior in PD by down-regulating the BDNF/TrkB/PSD95 expressions.

Objective:To evaluate the application of layered harvesting technique for thin anterolateral thigh flap (ALTF) based on preoperative perforator mapping by colour Doppler ultrasound (CDU) and digital subtraction angiography (DSA).Methods:From April 2023 to November 2023, 13 patients (14 flaps) with forearm and hand wounds. were treated in the Department of Hand Surgery, Beijing Jishuitan Hospital, Capital Medical University, In this study, they were 8 males and 5 females; aged from 19 to 58 years old, with a mean of 37 years old. Body Mass Index (BMI) was 17.30 - 31.87 kg/m 2 with an average of 23.64 kg/m 2. The flap area was 9 cm×6 cm-20 cm×13 cm; the flap thickness was 4-6 mm with an average of 5.2 mm. Before surgery, CDU was applied to determine the entrance of the perforator vessel and made skin marking. DSA technology was further used to relocate the position of the perforator vessel and the branches of the superficial fascia layer at the flap tangential position. Based on the precise perforator positioning, the thin ALTF was harvested between the deep and superficial layers of the superficial fascia. Regular outpatient follow-ups were conducted after surgery. Results:The 14 flaps had 1 to 2 perforators and 2 to 4 superficial fascia branches, and the preoperative positioning coincided with the intraoperative perforator entrance, and the distance was less than 1 cm. All patients were included in the follow-up from 1 to 7 months with a mean of 3.2 months. Only 1 patient had the complication delayed healing at the donor site. All flaps survived successfully and had a good appearance without secondary trimming.Conclusion:Preoperative CDU and DSA accurately locate the entrance of the perforator and the distribution of superficial fascial branches, and the layered harvesting technique for thin ALTF, effectively reduces the difficulty at harvesting of the thin flap and reduces damage to the donor site.

Objective : To investigate the activation of the mammalian target of rapamycin complex 1 (mTORC1) signaling pathway molecules during the process by which kaempferol (Kae) promotes osteogenic differentiation of mouse bone marrow mesenchymal cells (BMMCs) under cyclic and uniaxial tension. Methods : BMMCs isolated and cultured in vitro were subjected to uniaxial dynamic tension with a 10% shape variable. The appropriate concentration of Kae was selected by cytotoxicity testing. The endogenous mTOR signal was inhibited by pp242. Four hours after traction, alkaline phosphatase (ALP) and osteocalcin (OCN) were detected by chemical colorimetry and ELISA, and the relative concentration of intracellular calcium was detected by flow cytometry. Phosphorylation of mTOR, 4E/BP1, and ribosomal protein S6 kinases (S6K), which are the main molecules of the endogenous mTORC1 signaling pathway, and expression of osteogenic transcription factors (Runx2 and Osterix) were detected by western blotting (WB), and mRNA expression levels of the above factors were detected by qRT-PCR. Results : The cytotoxicity test showed that 10 μmol/L Kae had little inhibitory effect on cell proliferation but had the strongest osteogenic ability. Four hours after stretching, Kae effectively promoted the osteogenic differentiation of BMMCs. The expression of ALP was （153.04 ± 18.72） U/mg, the expression of OCN was （1.64 ± 0.25） U. The mRNA and protein levels of Runx2 and Osterix were upregulated, and the intracellular calcium content was decreased. The mRNA and protein phosphorylation of mTOR and S6K was upregulated, and the opposite effect was observed with 4E/BP1. After pp242 was added to inhibit mTOR signaling, mTOR and S6K mRNA and protein phosphorylation were downregulated, but 4E/BP1 mRNA and protein phosphorylation was upregulated. The osteogenic differentiation of BMMCs was also significantly inhibited, mRNA and protein expression of Runx2 and Osterix were significantly downregulated, ALP and OCN expression were downregulated, and intracellular calcium content was increased. Conclusion Kae promotes osteogenic differentiation of mouse BMMCs under uniaxial dynamic tension through the mTORC1 signaling pathway.

Objective: To investigate the expression of the mTORC1 signaling pathway during the osteogenic differentiation of mouse bone marrow mesenchymal cells (BMMSCs) under cyclic uniaxial tension and explore its possible role. Methods : The BMMSCs of mice were affected by uniaxial dynamic tensile force. Western blot was used to detect the expression changes of major molecules (mTOR, Raptor, S6K) in the endogenous mTORC1 signaling pathway at 0, 1, 2, 4, and 8 hours after stretching. Chemical colorimetry, ELISA and PCR were used to detect alkaline phosphatase (ALP), osteocalcin (OCN) and Runx2 mRNA, respectively. Then, inhibition, activation and control groups were established by administration of the drugs PP242, MHY1485 and PBS, respectively. Two hours after the stress, the expression of S6K was detected by western blot, and the expression of the osteogenic signal was continuously detected by the above methods. Results : Western blot analysis showed that the main molecules of the mTORC1 signaling pathway were all expressed within 8 hours after traction, and the highest expression was 2 hours after the stress. Compared with those in the control group, the ALP activity and OCN expression decreased and the Runx2 mRNA levels increased after the mTORC1 signal pathway was inhibited (P ＜ 0.001); ALP activity and OCN expression increased after the mTORC1 signal pathway was activated, while the Runx2 mRNA levels decreased (P ＜ 0.001). Conclusion The mTORC1 signaling pathway participates in the osteogenic differentiation of mouse BMMSCs under tension. The osteogenesis of BMMSCs under cyclic uniaxial tension would be enhanced if the mTORC1 signaling pathway was activated.

Objective:To validate the role of color Doppler ultrasound in an animal model to detect early heterotopic ossification (HO) after brain-traumatic/burn/tenotomy.Methods:Forty-four rats were randomly divided into two groups. Rats in experimental group ( n=22) were operated to build brain-traumatic/burn/tenotomy model and others in control group ( n=22) underwent only skin incision injury. Color Doppler ultrasound, X-ray film examination at 2, 3, 4, 6, 8 and 10 weeks post-injury were performed to follow up the progression of HO in both groups respectively. Histology was used to confirm bone formation. Results:In the experimental group, disorder structure with a hypoechoiccore in treated Achilles tendon was visualized using color Doppler ultrasound in the 2nd week. Additional tiny hyperechoic foci were observed in the 3rd week, which increased in the fourth week and fused into a mineralized island in the sixth week. No obvious abnormality was found in control group at the aforementioned time point. X-ray could detect heterotopic bone tissue in the sixth week in the experimental group but not in the control group. X-ray and HE stainning had confirmed bone formation in the tenth week in the experimental group.Conclusions:Color Doppler ultrasound can detect early HO and continuously follow up the progression of HO.

Objective : To explore the promoting effect of periostin on rapid distraction osteogenesis of the rabbit mandible and provide experimental evidence for the clinical use of periostin to promote osteogenesis. Methods: Twenty-four New Zealand male white rabbits underwent distraction osteogenesis, and after 3 days of retention, they were rapidly stretched at a stretch rate of 2 mm/d (total 5 d). The animals were randomly divided into group A and group B (12 per group). On the last day of the stretch, 0.5 mL of normal saline containing 40 μg of recombinant periostin was given to group B or an equal volume of normal saline was added to the control group (group A) for 8 days. At 4 weeks and 8 weeks post-stretch, 8 animals were randomly selected from each group to undergo a CT scan under general anesthesia. The bone mineral density and bone mineral content were detected by dual energy X-ray absorptiometry. Eight weeks post-stretch, all of the experimental animals were sacrificed. Six animals were randomly selected from each group for micro-CT and a histological examination, and the remaining animals were subjected to biomechanical tests. Results : CT images showed that the new bone formation in the distraction space of group B was significantly better than that of group A at 4 and 8 weeks post-stretch. At 4 weeks and 8 weeks post-stretch, the bone mineral density in group B was (0.157 ± 0.016) g/cm 2 and (0.234 ± 0.023) g/cm 2, respectively, and the bone mineral content was (0.096 ± 0.010) g and (0.204 ± 0.017) g, respectively. The above four means were significantly higher in group B than in group A (P < 0.001). The micro-CT images and data suggest that the stretch gap microstructure of group B has more mature features. Histological experiments showed that the trabecular bone of group B was thick and mature, with few chondrocytes. The biomechanical test results showed that the biomechanical strength of the distraction gap in group B was (228.47 ± 39.98) N, which was 1.24 times that of group A (P = 0.045). Conclusion Interstitial use of periosteal protein in the distraction space of the mandible in rabbits can promote local new bone formation and mineralization.

OBJECTIVE: To understand the exposure of occupational hazards, occupational and mental health status of high-speed railway locomotive drivers. METHODS: A total of 150 male high-speed railway locomotive drivers from Nanchang Railway administration were selected as experimental group, and 80 male ordinary train drivers were selected as control group by using a judgment sampling method. The occupational disease hazard testing and occupational health examinations were conducted in drivers of these two groups. The mental health status survey was conducted using the Symptom Checklist 90(SCL-90). RESULTS: The noise, power frequency electric field, formaldehyde, benzene, toluene, xylene and carbon dioxide in all the work place of these two groups were in line with the national occupational health standards. The exposure noise intensity of the experimental group was lower than that of the control group [(70.5±3.7) vs(77.4±4.1) dB(A), P<0.05]. The detection rates of hypertension and chronic gastritis were higher in the experimental group(18.7% vs 34.7%, 26.2% vs 42.0%, P<0.05). The detection rate of high frequency hearing loss decreased in the experimental group compared with the control group(22.5% vs 10.7%, P<0.05). The total score of SCL-90 in the experimental group was higher than that in the control group [(169.5±6.1) vs(148.0±6.0) score, P<0.01]. The positive rate of psychological symptoms was higher in the experimental group than that of the control group(41.3% vs 23.8%, P<0.01). CONCLUSION: The concentration/intensity of occupational disease hazards in the workplace of high-speed railway locomotives drivers is within normal limit. The occupational health status of high-speed railway locomotive drivers is generally good, but attention should be paid to their occupational mental health hazards.

Microemulsions are promising drug delivery systems for the oral administration of poorly water-soluble drugs. However, the evolution of microemulsions in the gastrointestinal tract is still poorly characterized, especially the structural change of microemulsions under the effect of lipase and mucus. To better understand the fate of microemulsions in the gastrointestinal tract, we applied small-angle X-ray scattering (SAXS) and fluorescence resonance energy transfer (FRET) to monitor the structural change of microemulsions under the effect of lipolysis and mucus. First, the effect of lipolysis on microemulsions was studied by SAXS, which found the generation of liquid crystalline phases. Meanwhile, FRET spectra indicated micelles with smaller particle sizes were generated during lipolysis, which could be affected by CaCl, bile salts and lecithin. Then, the effect of mucus on the structural change of lipolysed microemulsions was studied. The results of SAXS and FRET indicated that the liquid crystalline phases disappeared, and more micelles were generated. In summary, we studied the structural change of microemulsions in simulated gastrointestinal conditions by SAXS and FRET, and successfully monitored the appearance and disappearance of the liquid crystalline phases and micelles.