Analysis on infection sources and transmission chains of three outbreaks caused by 2019-nCoV Omicron variant in Beijing, China / 中华流行病学杂志

Objective: To investigate the infection sources and the transmission chains of three outbreaks caused by 2019-nCoV Omicron variant possibly spread through cross-border logistics in Beijing. Methods: Epidemiological investigation and big data were used to identify the exposure points of the cases. Close contacts were traced from the exposure points, and the cases' and environmental samples were collected for nucleic acid tests. Positive samples were analyzed by gene sequencing. Results: The Omicron variant causing 3 outbreaks in Beijing from January to April, 2022 belonged to BA.1, BA.1.1 and BA.2. The outbreaks lasted for 8, 12 and 8 days respectively, and 6, 42 and 32 cases infected with 2019-nCoV were reported respectively. International mail might be the infection source for 1 outbreak, and imported clothes might be the infection sources for another 2 outbreaks. The interval between the shipment start time of the imported goods and the infection time of the index case was 3-4 days. The mean incubation period (Q1, Q3) was 3 (2,4) days and the mean serial interval (Q1, Q3) was 3 (2,4)days. Conclusions: The 3 outbreaks highlighted the risk of infection by Omicron variant from international logistics-related imported goods at normal temperature. Omicron variant has stronger transmissibility, indicating that rapid epidemiological investigation and strict management are needed.

Epidemiological characteristics and serum antibody detection of a COVID-19 aggregated outbreak in vaccinated population / 中华预防医学杂志

An epidemiological investigation was conducted on a cluster epidemic of COVID-19 in the vaccinated population in Beijing in 2022, and serum samples were collected from 21 infected cases and 61 close contacts (including 20 cases with positive nucleic acid in the isolation observation period). The results of antibody detection showed that the IgM antibody of two infected persons was positive, and the IgG antibody positive rates of patients who were converted, not converted to positive and infected persons were 36.84% (7/19), 63.41% (26/41) and 71.43% (15/21), respectively. About 98.78% of patients had been vaccinated with the SARS-CoV-2 inactivated vaccine. The positive rate of IgG antibody in patients immunized with three doses of vaccine was 86.00% (43/50), which was higher than that in patients with one or two doses [16.12% (5/31)]. The antibody level of M (Q1, Q3) in patients immunized with three doses was 4.255 (2.303, 7.0375), which was higher than that in patients with one or two doses [0.500 (0.500, 0.500)] (all P values<0.001). The antibody level of patients who were vaccinated less than three months [7.335 (1.909, 7.858)] was higher than that of patients vaccinated more than three months after the last vaccination [2.125 (0.500, 4.418)] (P=0.007). The positive rate and level of IgG antibody in patients who were converted to positive after three doses were 77.78% (7/9) and 4.207 (2.216, 7.099), respectively, which were higher than those in patients who were converted after one or two doses [0 and 0.500 (0.500, 0.500)] (all P values<0.05).

Color-Tunable Binary Copolymers Manipulated by Intramolecular Aggregation and Hydrogen Bonding.

Construction of color-tunable luminescent polymeric materials with enhanced emission intensity and room-temperature phosphorescence (RTP) performance regulated by a single chromophore component is highly desirable in the scope of photoluminescent materials. Herein, a set of binary copolymers were facilely synthesized using free radical polymerization by selecting different types of polymer matrix and N-substituted naphthalimides (NPA) as chromophores. Surprisingly, the fluorescence emission of copolymers could be remarkably enhanced, because of the intramolecular aggregation of NPA manipulated by a single polymer chain in both solution and solid state. Moreover, RTP signals of binary copolymers were all clearly observed in the air without any processing procedure, because of the embedding of phosphors into hydrogen bonding networks after copolymerization with vinyl-based acrylamide monomers. Taking advantages of the synergistic effect of copolymerization-induced aggregation and copolymerization-induced rigidification to promote optical performance, UV stimulus-responsive luminescent polymer films with processability, flexibility, and adjustable emission wavelength were simply prepared using a drop-casting method in large scale, the setting of which is the basis for application in the fields of organic optoelectronics, information security, and bioimaging/sensing.

Tale of COF-on-MOF Composites with Structural Regulation and Stepwise Luminescence Enhancement.

Integrating metal-organic framework (MOF)-covalent organic framework (COF) allows versatile engineering of hybrid materials with properties superior to pristine components, especially COFs suffered from aggregation-caused quenching (ACQ), unlocking more possibilities to improve the luminescence of COFs. In this work, we prepared various MOF@COF composites with different COF layer thicknesses, in which stable UiO-66-NH2 served as the inner substrate and 1,3,5-benzenetricarboxaldehyde (BT), and 3,3'-dihydroxybenzidine (DH) were used to construct a COF layer. In addition to the conventional preparation method, we increased the ratio of BT and DH to be 1:2.5, and impressively, the morphologies of acquired UC (1:2.5) materials were quite different from the previous reticular structure and gradually extended from the spherical structure to the prickly structure with the increase of COF monomers. Remarkably, all of the UC materials possessed better luminescence properties than individual COF due to the limited COF layers. Meanwhile, UC-1 materials with an optimal COF layer displayed the strongest emission. In comparison with a single COF, the quantum yields of UC-1 and UC-1 (1:2.5) were increased nearly 7 times and 5 times, respectively. Moreover, the fluorescence of UC-1 materials was progressively enhanced via selective F- sensing. This work is expected to shed light on the potential hybridization of MOF-COF with structural adjustment, morphological design, and luminescence enhancement.

Tunable fluorescence emission based on multi-layered MOF-on-MOF.

Luminescent metal-organic frameworks (MOFs) have garnered considerable attention in various fields. Herein, we proposed a hierarchical confinement strategy based on MOF-on-MOF to tune luminescence emission ranging from blue to red including white light in a flexible way. The easily available ZIF-8 MOF was used as a host for the confinement of two kinds of size-matching dyes (perylene and rhodamine B) to obtain a layered ZIF-8@dye@ZIF-8@dye via in situ encapsulation and seed-mediated synthesis. ZIF-8@dye@ZIF-8@dye materials with different fluorescence emission in dispersed and solid states were both obtained by tuning the initial encapsulation concentration of dye and changing the structure of the inner and outer ZIF-8@dye layers. To our delight, ZIF-8@0.125perylene@ZIF-8@25RhB with white light emission in the dispersed state was obtained; meanwhile, ZIF-8@0.125perylene + 25RhB and mechanically mixed ZIF-8@0.125perylene + ZIF-8@25RhB could not realize white light emission under the same conditions, indicating that the proposed hierarchical confinement strategy facilitated white light regulation. Similarly, the emission of ZIF-8@dye@ZIF-8@dye in the solid state has also been investigated; ZIF-8@perylene@ZIF-8@3RhB with white light emission was obtained, while white light emission could not be achieved in ZIF-8@perylene + 3RhB and ZIF-8@perylene + ZIF-8@3RhB, which further indicated the importance of the hierarchical confinement strategy based on MOF-on-MOF. The proposed hierarchical confinement strategy may also inspire the development of other functional optical MOF materials.

Construction and Sensing Amplification of Raspberry-Shaped MOF@MOF.

MOFs@MOFs (metal-organic frameworks, MOFs) possess precise customized functionalities and predesigned structures that enable the implementation of structure and property regulation for specific functions in comparison to traditional single MOFs. However, the synthesis and fluorescence properties of multilayer MOFs@MOFs are still worth improving. Herein, a fluorescent raspberry-shaped MOF@MOF was constructed via optimized seed-mediated synthesis by tuning the reaction time, reaction mode, and reaction concentration, involving the initial synthesis of the UiO-66-NH2 core and then the coating of the UiO-67-bpy shell. The raspberry-shaped UiO-66@67-bpy showed stable fluorescence and desirable sensing selectivity for the Hg2+ ion under the interference of other ions; meanwhile, the raspberry-shaped UiO-66@67-bpy indicated amplified sensing performance than pure UiO-66-NH2, mechanically mixed UiO-66-NH2 + UiO-67-bpy, and UiO-66@UiO-67 counterpart due to the accumulation effect of outer UiO-67-bpy toward Hg2+. Density functional theory (DFT) calculations including adsorption energy calculations and electronic density difference analysis further showed that the enhanced fluorescence quenching was possibly attributed to the outer UiO-67-bpy enrichment promoting the charge transfer between Hg2+ and the ligands of fluorescent UiO-66@67-bpy. The synergistic effect of MOFs@MOFs unlocks more possibilities for the construction of enhanced sensors and other applications.

Symptomatic and Asymptomatic SARS-CoV-2 Infection and Follow-up of Neutralizing Antibody Levels.

Objective: To investigate neutralizing antibody levels in symptomatic and asymptomatic patients with coronavirus disease 2019 (COVID-19) at 6 and 10 months after disease onset. Methods: Blood samples were collected at three different time points from 27 asymptomatic individuals and 69 symptomatic patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Virus-neutralizing antibody titers against SARS-CoV-2 in both groups were measured and statistically analyzed. Results: The symptomatic and asymptomatic groups had higher neutralizing antibodies at 3 months and 1-2 months post polymerase chain reaction confirmation, respectively. However, neutralizing antibodies in both groups dropped significantly to lower levels at 6 months post-PCR confirmation. Conclusion: Continued monitoring of symptomatic and asymptomatic individuals with COVID-19 is key to controlling the infection.

An investigation on serum antibody level of varicella-zoster virus in healthy population in Beijing / 中华预防医学杂志

Objective: To assess the level and trend of varicella-zoster virus (VZV) antibody among healthy population in Beijing in 2017, after the five-year implementation of the two doses varicella vaccination strategy in 2012, and to provide evidence for scientific evaluation of immunization strategy. Methods: A total of 2 144 subjects in ten age groups from 8 districts of Beijing city were recruited in this study using cross-sectional survey based on multi-stage cluster random sampling method. Serum samples were collected and VZV antibody was detected by ELISA. The influencing factors of antibody concentration and positive rate were analyzed and compared with the study in 2012. The antibody concentration and antibody positive rate were analyzed by nonparametric test and χ² test respectively. Results: The ratio of subjects with registered residence in Beijing city to other provinces was 1∶1. The ratio of male to female was 1∶1.08. The median concentration of VZV antibody was 341.4 (78.6, 1 497.8) mIU/ml, and the total antibody positive rate was 71.1% (1 524/2 144). There were significant differences in antibody positive rate (χ²=736.39, P<0.01) and antibody concentration (χ²=740.34, P<0.01) among different age groups. The antibody positive rate generally increased with age (χ²trend=7.32, Ptrend<0.01). Among 862 children under 14 years old, the antibody positive rate of two doses vaccination 72.8% (182/250) was significantly higher than that of one dose vaccination 51.9% (154/297) (χ²=25.14, P<0.01). There was significant difference between 1-4 years old group (χ²=11.71, P<0.01) and 10-14 years old group (χ²=5.95, P=0.02), but not in 5-9 years old group (χ²=3.00, P=0.07). Compared with the study in 2012, the antibody positive rate increased in 5-9 years old group (χ²=14.35, P<0.01) and decreased in 1-4 years old group (χ²=11.51, P=0.01) in 2017. Conclusion: The recommended varicella booster vaccination has significantly improved the VZV antibody level of children in Beijing city. In the future, it is necessary to explore a more optimized two doses varicella vaccination schedule for children in combination with epidemiological evidence.

Survey of possible aerosol transmission of a COVID-19 epidemic caused by 2019-nCoV Delta variant / 中华流行病学杂志

Objective: To investigate the epidemiological characteristics and the transmission chain of a family clustering of COVID-19 cases caused by severe acute respiratory 2019-nCoV Delta variant in Changping district of Beijing. Methods: Epidemiological investigation was conducted and big data were used to reveal the exposure history of the cases. Close contacts were screened according to the investigation results, and human and environmental samples were collected for nucleic acid tests. Positive samples were analyzed by gene sequencing. Results: On November 1, 2021, a total of 5 COVID-19 cases caused by 2019-nCoV Delta variant were reported in a family detected through active screening. The infection source was a person in the same designated isolation hotel where the first case of the family cluster was isolated from 22 to 27, October. The first case was possibly infected through aerosol particles in the ventilation duct system of the isolation hotel. After the isolation discharge on October 27, and the first case caused secondary infections of four family members while living together from October 27 to November 1, 2021. Conclusion: 2019-nCoV Delta variant is prone to cause family cluster, and close attention needs to be paid to virus transmission through ventilation duct system in isolation hotels.

A real-world study of the efficacy and safety of sofosbuvir and velpatasvir in the treatment of HCV-infected patients in a county in northern China / 中华肝脏病杂志

Objective: To evaluate the real-world efficacy and safety of sofosbuvir and velpatasvir (SOF/VEL) tablets in the treatment of Chinese patients with chronic HCV infection. Methods: An open-label, single-center, prospective clinical study was conducted in a county in northern China. A total of 299 cases were enrolled. Of these, 161 cases with chronic hepatitis C and 73 cases with compensated cirrhosis received SOF/VEL for 12 weeks. 65 cases with decompensated cirrhosis received SOF/VEL combined with ribavirin for 12 weeks (22 cases) or SOF/VEL for 24 weeks (43 cases). Virological indicators, liver and renal function indexes, and liver stiffness measurement were detected at baseline, the fourth week of treatment, the end of treatment, and the 12-weeks of follow-up. Adverse reactions and laboratory abnormalities were observed during the course of treatment . The primary endpoint was undetectable rate of HCV RNA (SVR12) at 12 weeks of follow-up with the use of modified intention-to-treat (mITT) approach. Measurement data between two groups were compared using t-test. One Way ANOVA was used for comparison between multiple groups. Enumeration data were analyzed by chi-square test or Fisher's exact test. Results: 291 cases had completed treatment. HCV RNA was undetectable after 12 weeks of follow-up, and the SVR12 rate was 97.3% (95% confidence interval: 95.4%-99.3%). Among them, 97.4% of genotype 1b, 96.4% of genotype 2a, and 100% of those with undetected genotype achieved SVR12. The SVR12 rates in patients with chronic hepatitis C, compensated and decompensated liver cirrhosis were 98.1%, 98.6% and 93.8%, respectively. An improvement in alanine aminotransferase, aspartate aminotransferase and other liver biochemical indicators accompanied with virological clearance and reduced liver stiffness measurement was observed in patients with compensated cirrhosis, with statistically significant difference. There was no significant abnormality in renal function before and after treatment. The most common adverse reactions were fatigue, headache, epigastric discomfort and mild diarrhea. The overall adverse reactions were mild. One patient died of decompensated liver cirrhosis combined with massive upper gastrointestinal bleeding, which was unrelated to antiviral treatment. Four patients discontinued treatment prematurely due to adverse events. Relapse was occurred in four cases, and drug-resistance related mutations were detected in three cases. Conclusion: Sofosbuvir and velpatasvir tablets in Chinese HCV-infected patients with different genotypes, different clinical stages or previously treated with pegylated interferon combined with ribavirin resulted in higher SVR12, indicating that the treatment safety profile is good.

Supramolecular Engineering of Efficient Artificial Light-Harvesting Systems from Cyanovinylene Chromophores and Pillar[5]arene-Based Polymer Hosts.

Enhanced emission and adjustable wavelength for single luminogen systems are highly desirable in the scope of photoluminescent materials. Herein, a supramolecular strategy has been proposed for supramolecular assembly-induced enhanced emission and valid emission manipulation by fabricating an amphiphilic copolymer host material with pillar[5]arene units as the side chains, whereby cyanovinylene-based (CV) derivatives are anchored to the polymer hosts via host-guest interactions. The guest-bearing copolymers can further form luminescent supramolecular polymer nanoparticles (SPNs). Remarkably, the as-prepared SPNs exhibit dramatic emission enhancement and tunable fluorescence wavelength, ascribing to the synergetic effects involving the restriction of intramolecular motions and the prevented excimer formation for CV moieties, as endowed by host-guest interactions and the entanglement of the polymer chains. Furthermore, the SPNs can be established as efficient artificial light-harvesting systems via the inclusion of Nile red into the particles for broadened emission spectra. As a proof-of-concept study, the use of pillar[5]arene-containing polymer hosts largely facilitates the emission enhancement and wavelength adjustment for the inherent luminogens, setting the basis for the supramolecular design of highly tunable luminescent systems.

Polymyxin monotherapy versus polymyxin-based combination therapy against carbapenem-resistant Klebsiella pneumoniae: A systematic review and meta-analysis.

OBJECTIVES: This meta-analysis was performed to compare polymyxin monotherapy and polymyxin-based combination therapy for carbapenem-resistant Klebsiella pneumoniae (CR-KP) infections. METHODS: We conducted searches on MEDLINE, Embase and Cochrane Collaborative database for both observational studies and randomised controlled trials (RCTs) comparing polymyxin monotherapy with polymyxin-based combination therapy in patients with CR-KP infection. The primary outcome was mortality. We divided all included studies into several groups according to different combination-combination and different infection types. The odds ratio (OR) and 95% confidence intervals (CI) were calculated for outcome analysis. RESULTS: Ten studies with 481 patients were included. Polymyxin monotherapy was associated with higher mortality than polymyxin-based combination therapy in treatment of CR-KP bloodstream infections (BSI) (OR 1.93, 95% CI 1.14-3.27, P = 0.01) and ventilator-associated pneumonia (VAP)/hospital-acquired pneumonia (HAP) (OR 3.82, 95% CI 1.15-12.71, P = 0.03). In subgroup analysis of different combinations, mortality was significantly higher with polymyxin monotherapy compared with combination therapy with tigecycline (OR 1.88, 95% CI 1.05-3.37, P = 0.03), or with cabapenem (OR 3.11, 95% CI 1.25-7.74, P = 0.01), but no differences were found in combinations with aminoglycosides (OR 1.29, 95% CI 0.72-2.29, P = 0.38). Three-drug combination therapy including polymyxin was also associated with significant survival benefit (OR 3.86, 95% CI 1.60-9.32, P = 0.003). CONCLUSIONS: Polymyxin-based combination therapy provides significant survival benefit in treatment of CR-KP, which appears to be more pronounced when a carbapenem or tigecycline is included in the regimen.

Effect of Capsular Closure on Outcomes of Hip Arthroscopy for Femoracetabular Impingement: A Systematic Review and Meta-analysis.

OBJECTIVE: To evaluate the effect of hip arthroscopy with or without capsular closure in femoracetabular impingement (FAI) by meta-analysis. METHODS: Pertinent studies were identified by searching Pubmed, EMBASE databases with the last search update on 16 February 2020. Studies that reported hip arthroscopy for FAI were collected. Meta-analysis was performed by the use of Review Manager 5.3 software. The odds ratios (OR) and mean differences (MD) were used to compare dichotomous and continuous variables. Additionally, the I2 was used to assess heterogeneity among studies, and the fixed-effects model or the random-effects model was selected for the quantitative analysis. Outcomes were evaluated by forest plots. For statistical analysis, P < 0.05 was considered significant. RESULTS: There was no significant difference among the preoperative mHHS (MD = -2.66，95% CI [-7.25, 1.92], I2 = 80%, P = 0.25), preoperative (MD = -4.94, 95% CI [-11.56, 1.67], I2 = 50%, P = 0.14) and postoperative HOS-SSS (MD = -1.00, 95% CI [-6.98, 4.98], I2 = 66%, P = 0.74), patient satisfaction (MD = 0.03, 95% CI [-0.25, 0.31], I2 = 19%, P = 0.84; OR = 0.94, 95% CI [0.59, 1.50], I2 = 0%, P = 0.78), complications (OR = 1.23, 95%CI [0.56, 2.67], I2 = 0%, P = 0.61), revisions (OR = 1.77, 95% CI [0.87, 3.60], I2 = 36%, P = 0.11), and surgery time (SMD = -0.38, 95% CI [-1.16, 0.40], I2 = 92%, P = 0.34) between the capsule closure group and the non-closure group. For the comparison of postoperative mHHS (MD = -2.66, 95% CI [-7.25, 1.92], I2 = 80%, P = 0.25) and HOS-ADL (MD = -4.20, 95% CI [-5.75, -2.65], I2 = 24%, P < 0.00001), the score of the non-closure group was significantly better than that of the closure group. CONCLUSIONS: Remain capsule unclosed after hip arthroscopy for FAI may, to some extent, has a better postoperative functional score than the non-closure treatment.

Effect of Panax Notoginseng Saponins on Breast Cancer Cell Line 4T1 in Tumor-bearing Mice Through MEKK1/SEK1/JNK1/AP-1 Pathway / 中国实验方剂学杂志

Objective:To explore the potential mechanisms of Panax Notoginseng Saponins （PNS） on growth inhibition of breast cancer cell line 4T1 in tumor-bearing mice by investigating the mitogen-activated protein kinase kinase kinase 1 （MEKK1）/stress activated protein kinase （SAPK）/extracellular regulated protein kinases （Erk） Kinase （SEK1）/c-Jun N-terminal kinase 1 （JNK1）/activator protein-1 （AP-1） signaling pathways. Method:The 4T1 breast cancer mice model was established. Forty-eight mice with successful modeled and randomly divided into the low， medium and high-dose PNS groups （10， 20， 40 mg·kg-1） and the model control group （12 mice in each group）. The PNS groups received intraperitoneal injection with dosage of 10 mL·kg-1， while the controlled group was given the same dosage of saline. After administration with PNS for 28 days， tumor tissues were isolated， weighed， sliced and homogenized. Tumor cell apoptosis was detected by TdT mediated-dUTP nick end labeling （TUNEL） staining. The mRNA expressions of MEKK1， SEK1， JNK1 and AP-1 in tumor tissue were detected by Real-time polymerase chain reaction（Real-time PCR）. The protein expressions of MEKK1， SEK1， JNK1 and AP-1 in tumor tissue were detected by immunofluorescence staining and Western blot. Result:Compared with model group， the tumor weights of medium-dose and high-dose PNS groups were decreased significantly （P<0.05）. TUNEL staining showed that the number of apoptotic tumor cells increased with the rise of dosage of PNS （P<0.05）. The medium-dose and high-dose PNS groups showed a significant increase in the mRNA expressions of MEKK1， SEK1， JNK1 and AP-1 as well as the protein expressions of MEKK1， SEK1， JNK1 and AP-1 in tumor tissues （P<0.05）， with statistically significant differences （P<0.05）. Conclusion:PNS could inhibit the tumor growth of breast cancer cell line 4T1 in tumor-bearing mice， which may be related to the activation of MEKK1/SEK1/JNK1/AP-1 signaling pathways.

Efficient Aggregation-Induced Emission Manipulated by Polymer Host Materials.

Linear copolymer hosts bearing a number of pillar[5]arene dangling side chains are synthesized for the facile construction of highly emissive supramolecular polymer networks (SPNs) upon noncovalently cross-linking with a series of tetraphenyethylene (TPE)-based tetratopic guests terminated with different functional groups through supramolecular host-guest interactions. An extremely high fluorescence quantum yield (98.22%) of the SPNs materials is obtained in tetrahydrofuran (THF) by fine-tuning the parameters, and meanwhile supramolecular light-harvesting systems based on spherical supramolecular nanoparticles are constructed by interweaving 9,10-distyrylanthracene (DSA) and TPE-based guest molecules of aggregation-induced emission (AIE) with the copolymer hosts in the mixed solvent of THF/H2 O. The present study not only illustrates the restriction of the intramolecular rotations (RIR)-ruled emission enhancement mechanism regulated particularly by macrocyclic arene-containing copolymer hosts, but also suggests a new self-assembly approach to construct high-performance light-harvesting materials.

Application and Prospect of Mixed Reality Technology in Medical Field.

Mixed reality (MR) technology is a new digital holographic image technology, which appears in the field of graphics after virtual reality (VR) and augmented reality (AR) technology, a new interdisciplinary frontier. As a new generation of technology, MR has attracted great attention of clinicians in recent years. The emergence of MR will bring about revolutionary changes in medical education training, medical research, medical communication, and clinical treatment. At present, MR technology has become the popular frontline information technology for medical applications. With the popularization of digital technology in the medical field, the development prospects of MR are inestimable. The purpose of this review article is to introduce the application of MR technology in the medical field and prospect its trend in the future.

Dysregulated miR-127-5p contributes to type II collagen degradation by targeting matrix metalloproteinase-13 in human intervertebral disc degeneration.

BACKGROUND: Intervertebral disc degeneration (IDD) is a chronic disease associated with the degradation of extracellular matrix (ECM). Matrix metalloproteinase (MMP)-13 is a major enzyme that mediates the degradation of ECM components. MMP-13 has been predicted to be a potential target of miR-127-5p. However, the exact function of miR-127-5p in IDD is still unclear. OBJECTIVE: We designed this study to evaluate the correlation between miR-127-5p level and the degeneration of human intervertebral discs and explore the potential mechanisms. METHODS: miR-127-5p levels and MMP-13 mRNA levels were detected by quantitative real-time polymerase chain reaction (qPCR). To determine whether MMP-13 is a target of miR-127-5p, dual luciferase reporter assays were performed. miR-127-5p mimic and miR-127-5p inhibitor were used to overexpress or downregulate miR-127-5p expression in human NP cells, respectively. Small interfering RNA (siRNA) was used to knock down MMP-13 expression in human NP cells. Type II collagen expression in human NP cells was detected by qPCR, western blotting, and immunofluorescence staining. RESULTS: We confirmed that miR-127-5p was significantly downregulated in nucleus pulposus (NP) tissue of degenerative discs and its expression was inversely correlated with MMP-13 mRNA levels. We reveal that MMP-13 may act as a target of miR-127-5p. Expression of miR-127-5p was inversely correlated with type II collagen expression in human NP cells. Moreover, suppression of MMP-13 expression by siRNA blocked downstream signaling and increased type II collagen expression. CONCLUSION: Dysregulated miR-127-5p contributed to the degradation of type II collagen by targeting MMP-13 in human IDD. Our findings highlight that miR-127-5p may serve as a new therapeutic target in IDD.

Analysis of Sagittal Parameters in Patients Undergoing One- or Two-Level Closing Wedge Osteotomy for Correcting Thoracolumbar Kyphosis Secondary to Ankylosing Spondylitis.

STUDY DESIGN: Retrospective analysis of clinical records. OBJECTIVE: To assess and compare the improvement in sagittal balance after one- or two-level closing wedge osteotomy for correcting thoracolumbar kyphosis secondary to ankylosing spondylitis (AS). SUMMARY OF BACKGROUND DATA: Closing wedge osteotomy represents a common approach to correct kyphosis in AS. Although several reports have described the outcomes of one- or two-level closing wedge osteotomy in terms of sagittal parameters, data comparing the outcomes of these procedures are scarce. METHODS: Between January 2010 and December 2014, 22 patients with AS underwent closing wedge osteotomy (one-level, 12 patients; two-level, 10 patients) for correcting thoracolumbar kyphosis (mean follow-up, 24.8 months; range, 12-60 months). Preoperative and postoperative chin-brow vertical angle, and the sagittal parameters of the vertebral osteotomy segment were documented and compared. Perioperative and postoperative complications were also recorded. RESULTS: The chin-brow vertical angle improved significantly, from 55.0°â€Š±â€Š27.3° to 4.7°â€Š±â€Š4.9° and from 38.2°â€Š±â€Š14.9° to 3.2°â€Š±â€Š5.4° in the one-level and two-level groups, respectively. The total correction (thoracic kyphosis and lumbar lordosis) was 32.8°â€Š±â€Š18.2° and 53.7°â€Š±â€Š9.4° in the one-level and two-level groups, respectively. No death, complete paralysis, or vascular complications occurred during the procedure, but cerebrospinal fluid leak was noted in one and two patients from the one-level and two-level groups, respectively. A distal pedicle screw adjacent to the osteotomy segment became loose during surgery in one patient (one-level group). Postoperatively, no transient neurological deficit, infection, delay union, or loosening or breaking of the internal fixation devices was observed. Osteotomy site fusion was achieved in all patients, and the Oswestry Disability Index scores improved significantly. CONCLUSION: Closing wedge osteotomy is effective and safe for correcting thoracolumbar kyphosis in patients with AS. Significant correction and improvement in all sagittal parameters were noted in both groups, but two-level closing wedge osteotomy provided better correction. LEVEL OF EVIDENCE: 3.

Effects of High Thoracic Epidural Anesthesia on Cerebral Blood Flow and Hippocampal Apoptosis during Global Cerebral Ischemia and Reperfusion in Rats / 现代生物医学进展

Objective:To investigate the effects of high thoracic epidural anesthesia (HTEA) on the cerebral blood flow (CBF) and hippocampal apoptosis-related proteins Bcl-2 and Bax during global cerebral ischemia and reperfusion (GCI) in rats.Methods:Fifteen-minute global ischemia was established by 4-vessel occlusion and epidural catheterization was performed through T4-5 intervertebral spaces in adult male Wistar rats.According to the different drugs infused into the epidural space,the rats were randomly divided into four groups:Sham group (0.9 ％ NaC1),Sham-HTEA group (0.25 ％ bupivacaine),GCI group (global cerebral ischemia,0.9 ％ NaC1) and HTEA group (global cerebral ischemia,0.25 ％ bupivacaine).And 0.25 ％bupivacaine or 0.9 ％ saline (20 μL·h-1) was infused continuously to the thoracic epidural space from 15 minutes before ischemia to 24 hours after reperfusion.Mean arterial pressure (MAP),heart rate (HR) and cerebral blood flow (CBF) were determined until 2 hours after reperfusion,and the hippocampal Bcl-2 and Bax proteins at 24 hours after reperfusion were examined by Western-blot.Results:Compared with the GCI group,HTEA group has no significant difference on MAP and HR during ischemia and 2 hours after reperfusion,andcompared with the Sham group,MAP in GCI group increased in ischemia 0 min and decreased in reperfusion 0 min.The CBF in HTEA group was significantly lower than that in GCI group (123.1％± 35.2％ vs 177.5％± 32.4％,P＜0.01) in reperfusion 10 min,and higher than that in GCI group during the hypoperfusion of 60 to 120 minutes after reperfusion (P＜0.05),and the ratio of Bax/Bcl-2 in hippocampus was significantly decreased in HTEA group 24 hours after reperfusion (P＜0.01).Conclusions:Continuous HTEA infusion of 0.25 ％ bupivacaine 20 μL ·h-1 could maintain the hemodynamic stability,and improve the CBF of hypoperfusion period in rats,as well as reduce the ratio of Bax/Bcl-2 at 24 hours after reperfusion.