Publications by authors named "Teng Ma"

610 Publications

Electrostatically Controlled and Polymerization of Diacetylene-Containing Peptide Amphiphiles in Living Cells.

ACS Macro Lett 2022 Feb 19;11(2):223-229. Epub 2022 Jan 19.

Hubei Engineering Research Center for Biomaterials and Medical Protective Materials, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China.

Precise control of diacetylene-containing peptide amphiphile (DPA) based supramolecular architectures is important for their polymerization behaviors and biomedical applications. Herein, we reported two DPAs (cationic PA-NH and zwitterionic PA-OH) with a similar molecular structure, which exhibited completely opposite polymerization behaviors in aqueous solution and living cells. Specifically, PA-NH was unpolymerizable in aqueous solution but underwent polymerization to respond to the intracellular microenvironment. On the contrary, zwitterionic PA-OH was polymerized in solution, rather than inside living cells. Based on the results of cell viability and total internal reflection fluorescent microscopy measurement, PA-OH exhibited higher affinity with cell membranes and lower cytotoxicity than those of PA-NH. Therefore, it is suggested that the polymerization of PA-NH should be responsive for greater cytotoxicity, rather than the membrane affinity. This study provides an in-depth understanding of the role of charge properties in the polymerization behavior of DPAs and seeks their potential biomedical applications.
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http://dx.doi.org/10.1021/acsmacrolett.1c00735DOI Listing
February 2022

Outcomes for a custom-made anchor-like plate combined with cerclage in the treatment of inferior pole patellar fracture.

BMC Musculoskelet Disord 2022 May 14;23(1):452. Epub 2022 May 14.

Department of Orthopaedics and Trauma, Hong Hui Hospital, Xi'an Jiaotong, University College of Medicine, No. 555, East Youyi Road, Xi'an, 710000, Shaanxi, China.

Objective: An inferior pole fracture of the patella requires surgical treatment to restore the knee extension mechanism of the knee joint. Different from other types of patellar fractures, inferior pole fractures are usually comminuted, and other traditional fixation methods, such as tension band wiring, may not meet the fixation needs. We propose fixing inferior pole fractures of the patella with a custom-made anchor-like plate combined with cerclage and report the surgical outcomes.

Material And Methods: This is a retrospective clinical study. From June 2018 to August 2020, 21 patients with inferior patella fracture treated at Hong Hui Hospital Affiliated to Xi'an Jiaotong University received a custom-made anchor-like plate combined with cerclage. Complications of the surgical fixation methods and final knee function were used as the main outcome measures.

Results: All fractures achieved good union, and the union time ranged from 8 to 12 weeks. No patients had serious complications, such as internal fixation failure or infection. The average duration of surgery of patients was 75.05 7.26 min, and the intraoperative blood loss was 60.099.49 ml. At the last follow-up, the range of motion of the knee was 120°-140°, with an average of 131.436.92°, the Bostman score was 27-30, and the Lysholm score ranged from 82 to 95. All patients showed good knee function one year after the operation.

Conclusion: We used a modified T-shaped plate combined with cerclage technology to fix inferior fractures pole of the patella, providing reliable fixation, allowing early functional exercise of the knee joint, and providing patients with good knee joint function after surgery.
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http://dx.doi.org/10.1186/s12891-022-05413-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9107257PMC
May 2022

TARBP2-stablized SNHG7 regulates blood-brain barrier permeability by acting as a competing endogenous RNA to miR-17-5p/NFATC3 in Aβ-microenvironment.

Cell Death Dis 2022 May 13;13(5):457. Epub 2022 May 13.

Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, 110122, China.

Breakdown of blood-brain barrier (BBB) is recognized as serious pathological marker of Alzheimer's disease development. Studies confirmed that β-amyloid (Aβ) deposition induced high BBB permeability by disrupting tight junction (TJ) proteins formed from endothelial cells (ECs). Here, we found TARBP2, SNHG7 and NFATC3 in expressions were increased and miR-17-5p expression was decreased in Aβ(1-42)-incubated ECs. Overexpression of TARBP2, SNHG7 and NFATC3 elevated BBB permeability and knockdown of them had converse results. Agomir-17-5p decreased BBB permeability and antagomir-17-5p increased BBB permeability. TARBP2 as a RNA-binding protein (RBP) bound to SNHG7 and resulted in longer half-life of SNHG7. The decreased expression of miR-17-5p had a negative post-transcriptional regulation to NFATC3, leading to the increased expression of NFATC3. In addition, SNHG7 regulated NFATC3 expression by acting as a molecule sponge targeting to miR-17-5p. NFATC3 inhibited TJ proteins expression by functioning as a transcription factor. TARBP2/SNHG7/miR-17-5p/NFATC3 pathway implied a potential mechanism in studies of BBB changes in AD pathological progression.
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http://dx.doi.org/10.1038/s41419-022-04920-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9106673PMC
May 2022

Percutaneous reduction with double screwdrivers versus limited open reduction in the treatment of irreducible extracapsular hip fractures.

BMC Musculoskelet Disord 2022 May 6;23(1):429. Epub 2022 May 6.

Department of Orthopedic Surgery, Xi'an Jiaotong University, Hong Hui hospital, Xi'an, 710054, Shaanxi, China.

Background: The reduction in irreducible extracapsular hip fractures has always been controversial. Here, we present a new minimally invasive reduction technique and compare it with limited open reduction (LOR) to treat irreducible extracapsular hip fractures.

Methods: From January 2016 to January 2018, our institution treated 653 patients with extracapsular hip fractures by intramedullary fixation. Among them, 525 cases got a successful closed reduction. The other 128 were irreducible and reduced by percutaneous reduction with double screwdrivers (PRDS) or LOR. There were 66 cases in the PRDS group while 62 in the LOR group. All fractures were classified using the Evans-Jensen classification. In addition, the differences in incision length, blood loss, fluoroscopic number, operation time, inpatient time, weight training time, Harris score, and complications were analyzed.

Results: The incision length was 8.4 ± 1.4 cm in the PRDS group and 15.3 ± 3.0 cm in the LOR group, respectively (p < 0.05); blood loss was equal to 151 ± 26 and 319 ± 33 ml, respectively (p < 0.05); fluoroscopic number was 14 ± 3 and 8 ± 2, respectively (p < 0.05); operation time was 44 ± 9 and 73 ± 11 min, respectively (p < 0.05); inpatient time was 6.2 ± 1.7 and 8.4 ± 2.2 days, respectively (p < 0.05); weight training time after the operation was 4.5 ± 1.5 and 10.7 ± 1.8 days, respectively (p < 0.05); and the excellent rate of Harris score was 92.4% and 88.7%, respectively (p > 0.05). There was no significant difference in complication incidence between the two groups (p > 0.05).

Conclusions: The PRDS group presented better clinical effects for managing irreducible extracapsular hip fractures than the LOR. Therefore, the PRDS technique could be the first reduction choice for patients with irreducible fractures.
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http://dx.doi.org/10.1186/s12891-022-05390-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9077818PMC
May 2022

Source identification and characteristics of dissolved organic matter and disinfection by-product formation potential using EEM-PARAFAC in the Manas River, China.

RSC Adv 2021 Aug 23;11(46):28476-28487. Epub 2021 Aug 23.

School of Chemistry and Chemical Engineering, Shihezi University, Key Laboratory of Environmental Monitoring and Pollutant Control of Xinjiang Bingtuan Xinjiang 832003 China

Dissolved organic matter (DOM) is ubiquitous in natural water and reacts with disinfectants to form disinfection by-products (DBPs). The analysis of DOM in raw water is helpful in evaluating the formation potential of DBPs. However, there is relatively little research on the DOM identification of raw water in northern China. In this study, the sources and characteristics of DOM were investigated in the samples collected from the Manas River. Dissolved organic carbon (DOC), UV, specific ultraviolet absorbance, and fluorescence indices (fluorescence index, humification index, and biological index) were measured to characterize the DOM, and trihalomethanes (THMs) were quantified following formation potential tests with free chlorine. The maximum amount of total trihalomethane formation potential (THMsFP) was 225.57 μg L. The DOM of the Manas River consisted of microorganisms and soil resources. The excitation-emission matrix combined with parallel factor analysis (EEM-PARAFAC) identified microbial humus (C1, 54%) and tryptophan-like protein (C2, 46%). PARAFAC components were evaluated as the precursor surrogate parameters of THMsFP. Additionally, the linear THMsFP correlation was stronger with C1 + C2 ( = 0.529, < 0.01) than with C1 ( = 0.485, < 0.01). Thus, C1 + C2 is an accurate THMsFP precursor surrogate parameter for the Manas River, and the use of fluorescence spectroscopy may be a robust alternative for predicting DOC removal.
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http://dx.doi.org/10.1039/d1ra03498gDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9038026PMC
August 2021

Endoscopic Ultrasound Localization Microscopy for the Evaluation of the Microvasculature of Gastrointestinal Tract Tumors in Rabbits.

IEEE Trans Biomed Eng 2022 Apr 27;PP. Epub 2022 Apr 27.

Objective: The morphological and hemodynamic characterization of the microvascular network around the gastrointestinal (GI) tract can be of significant clinical value for the early diagnosis and treatment of GI tract cancer. Ultrasound localization microscopy (ULM) imaging has been demonstrated to be capable of resolving the microvascular network. However, the endoscopic application of ULM imaging techniques is still unknown. In this study, an endoscopic ultrasound localization microscopy (e-ULM) imaging technique was developed to evaluate the changes of microvasculature during the GI tract tumor growth.

Methods: A customized circular array transducer (center frequency: 6.8 MHz) and the coherent diverging wave compounding method were used to generate B-mode images. Spatiotemporal singular value decomposition processing was used to eliminate the background signals before signal localizations. The centroids of spatially isolated signals were localized and summed to generate the final super-resolution image.

Results: The final microvasculature map of rabbit GI tract tumor reveals that e-ULM can be used to surpass the diffraction limit in traditional endoscopic ultrasound (EUS) imaging. Furthermore, it is observed that data from different stages of tumor growth exhibit significant differences in microvascular pattern and density.

Conclusion: Our study demonstrated the implementations and applications of in vivo e-ULM imaging techniques for the evaluation of the microvasculature of GI tumors.

Significance: Efficient e-ULM imaging technique shows promise for clinical translational studies, particularly for the early diagnosis of GI tract cancers.
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http://dx.doi.org/10.1109/TBME.2022.3170557DOI Listing
April 2022

Acute shortening and re-lengthening versus antibiotic calcium sulfate-loaded bone transport for the management of large segmental tibial defects after trauma.

J Orthop Surg Res 2022 Apr 10;17(1):219. Epub 2022 Apr 10.

Department of Orthopaedic Surgery, Hong Hui hospital, Xi'an Jiaotong University College of Medicine, Xi'an, 710054, Shaanxi, China.

Background: The purpose of this paper was to compare the clinical effects of acute shortening and re-lengthening (ASR) technique with antibiotic calcium sulfate-loaded bone transport (ACSBT) technique for the management of large segmental tibial defects after trauma.

Methods: In this retrospective study, 68 patients with large segmental tibial defects were included and completely followed. The bone loss was 3-10 cm. ASR group included 32 patients, while ACSBT group contained 36. There was no significant difference in demographic information between the two groups. The external fixation time (EFT) and external fixation index (EFI) were compared. Bone defect healing and limb functions were evaluated according to the Association for the Study and Application of the Method of Ilizarov (ASAMI) criteria. Complications were compared by Paley classification.

Results: The mean EFT was 9.2 ± 1.8 months in ASR group and 10.1 ± 2.0 months in ACSBT group, respectively. The mean EFI was 1.5 ± 0.2 month/cm and 1.4 ± 0.3 month/cm. According to the ASAMI criteria, in ASR group bone defect healing was excellent in 22 cases, good in 7 cases and fair in 3 cases. In ACSBT group, it was excellent in 23 cases, good in 11 cases and fair in 2 cases. In ASR group, the limb function was excellent in 15 cases, good in 7 cases and fair in 10 cases, while it was excellent in 14 cases, good in 9 cases and fair in 13 cases with ACSBT group. There was no significant difference in EFI, bone defect healing and limb functions between the two groups (p > 0.05). The mean number of complications per patient in ACSBT group was significantly lower than that in ASR group (p < 0.05).

Conclusion: Both techniques can be successfully used for the management of large segmental tibial defects after trauma. There was no significant difference in EFI, limb functions and bone defect healing between the two groups. Compared with ASR group, the complication incidence in ACSBT group was lower, especially the infection-related complications. Therefore, for patients with large segmental bone defects caused by infection or osteomyelitis, ACSBT technique could be the first choice.
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http://dx.doi.org/10.1186/s13018-022-03109-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8996420PMC
April 2022

Pulsed Electromagnetic Field Alleviates Intervertebral Disc Degeneration by Activating Sirt1-Autophagy Signaling Network.

Front Bioeng Biotechnol 2022 21;10:853872. Epub 2022 Mar 21.

Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, China.

Intervertebral disc (IVD) degeneration is regarded as a major contributor to low back pain (LBP), causing serious economic burden on individuals and society. Unfortunately, there are limited effective treatment for IVD degeneration. Pulsed electromagnetic field (PEMF) is an economical and effective physical therapy method, with reduced side-effects. It offers certain protection to a number of degenerative diseases. Therefore, understanding the underlying mechanism of PEMF on IVD is important for improving the PEMF therapeutic efficiency. In this study, PEMF up-regulated extracellular matrix (ECM) related genes in degenerated nucleus pulposus (NP) cells. It also increased SIRT1 expression and promoted autophagy in degenerated NP cells. In contrast, the autophagy suppressor 3-methyladenine (3-MA) reversed the beneficial effect of PEMF on ECM production. Similarly, the SIRT1 enzyme activity suppressor EX 527 also inhibited the effect of PEMF on autophagy and ECM production in NP cells, thereby suggesting that PEMF regulated ECM related genes expression through SIRT1-autophagy signaling pathway. Lastly, PEMF significantly reduced IVD degeneration in a rat model of IVD degeneration . In summary, our study uncovers a critical role of SIRT1-dependent autophagy signaling pathway in ECM protection and thus in the establishment of therapeutic effect of PEMF on IVD degeneration.
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http://dx.doi.org/10.3389/fbioe.2022.853872DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8978825PMC
March 2022

Integrated US-OCT-NIRF Tri-modality Endoscopic Imaging System for Pancreaticobiliary Duct Imaging.

IEEE Trans Ultrason Ferroelectr Freq Control 2022 Apr 4;PP. Epub 2022 Apr 4.

Pancreaticobiliary carcinomas is a highly malignant gastrointestinal tumor. Most pancreaticobiliary cancers arise from epithelial proliferations within the pancreaticobiliary ducts, referred to as pancreatic intraepithelial neoplasias (PanINs). Some PanINs are benign metaplasia, while others progress to invasive duct adenocarcinoma (IDAC). However, there is no standard programme to diagnose the progression from PanINs to IDAC. In this study, we present a tri-modality imaging system, which integrates ultrasound (US), optical coherence tomography (OCT), and near-infrared fluorescence (NIRF) for pancreaticobiliary duct imaging. This system can obtain OCT, US, and NIRF images in real time with a frame rate of 30 frames per second. For the endoscopy probe with an outer diameter of 0.9 mm, the US transducer and fiber ball lens were placed back to back. In vivo experiments were performed on the rectums of Sprague-Dawley rats to demonstrate the imaging performance of US, OCT, and fluorescence angiography. An ex vivo experiment on a human pancreatic duct was performed for a more accurate assessment of the pancreaticobiliary duct. The tomography images of rat rectums and human pancreatic ducts were correlated with hematoxylin and eosin (H&E) histology to check the measurement accuracy. The integrated tri-modality system has great clinical potential in mechanism studies, early diagnosis, and prognosis evaluation of malignant pancreaticobiliary carcinomas.
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http://dx.doi.org/10.1109/TUFFC.2022.3164777DOI Listing
April 2022

Circadian Rhythm Modulates the Therapeutic Activity of Pulsed Electromagnetic Fields on Intervertebral Disc Degeneration in Rats.

Oxid Med Cell Longev 2022 25;2022:9067611. Epub 2022 Mar 25.

Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, China 710032.

Circadian rhythm (CR) imparts significant benefits in treating multiple diseases, such as heart diseases and arthritis. But the CR effect on intervertebral disc degeneration (IVDD) therapy remains unclear. Recent studies revealed that pulsed electromagnetic fields (PEMF) are capable of alleviating IVDD. In this study, we evaluated the CR-mediated regulation of PEMF therapeutic effect on IVDD induced by rat tail disc needle puncture. Our results demonstrated that the daytime PEMF stimulation (DPEMF) is more effective than the nighttime PEMF (NPEMF) in delaying IVDD. Moreover, the rats treated with DPEMF maintained better disc stability and histology after 8 weeks, relative to NPEMF. CR and PEMF cotherapies were also examined in cellular models, whereby serum shock was used to induce different levels of clock gene expression in the nucleus pulposus (NP), thus imitating CR . PEMF at ZT8 (higher level of clock gene expression) correlated with a higher extracellular matrix (ECM) component expression, compared to ZT20 (lower level of clock gene expression). Taken together, these data suggest a strong role of CR in regulating the beneficial effect of PEMF on IVDD. Our findings provide a potential clinical significance of CR in optimizing PEMF positive effects on IVDD.
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http://dx.doi.org/10.1155/2022/9067611DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8975688PMC
April 2022

Biological roles of RNA mC modification and its implications in Cancer immunotherapy.

Biomark Res 2022 Apr 1;10(1):15. Epub 2022 Apr 1.

Department of Cellular and Molecular Biology, Beijing Chest Hospital, Capital Medical University/Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, 101149, China.

Epigenetics including DNA and RNA modifications have always been the hotspot field of life sciences in the post-genome era. Since the first mapping of N6-methyladenosine (mA) and the discovery of its widespread presence in mRNA, there are at least 160-170 RNA modifications have been discovered. These methylations occur in different RNA types, and their distribution is species-specific. 5-methylcytosine (mC) has been found in mRNA, rRNA and tRNA of representative organisms from all kinds of species. As reversible epigenetic modifications, mC modifications of RNA affect the fate of the modified RNA molecules and play important roles in various biological processes including RNA stability control, protein synthesis, and transcriptional regulation. Furthermore, accumulative evidence also implicates the role of RNA mC in tumorigenesis. Here, we review the latest progresses in the biological roles of mC modifications and how it is regulated by corresponding "writers", "readers" and "erasers" proteins, as well as the potential molecular mechanism in tumorigenesis and cancer immunotherapy.
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http://dx.doi.org/10.1186/s40364-022-00362-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8973801PMC
April 2022

Gait Phase Subdivision and Leg Stiffness Estimation During Stair Climbing.

IEEE Trans Neural Syst Rehabil Eng 2022 5;30:860-868. Epub 2022 Apr 5.

Leg stiffness is considered a prevalent parameter used in data analysis of leg locomotion during different gaits, such as walking, running, and hopping. Quantification of the change in support leg stiffness during stair ascent and descent will enhance our understanding of complex stair climbing gait dynamics. The purpose of this study is to investigate a methodology to estimate leg stiffness during stair climbing and subdivide the stair climbing gait cycle. Leg stiffness was determined as the ratio of changes in ground reaction force in the direction of the support leg F (leg force) to the respective changes in length L during the entire stance phase. Eight subjects ascended and descended an instrumented staircase at different cadences. In this study, the changes of leg force and length (force-length curve) are described as the leg stiffness curve, the slope of which represents the normalized stiffness during stair climbing. The stair ascent and descent gait cycles were subdivided based on the negative and positive work fluctuations of the center-of-mass (CoM) work rate curve and the characteristics of leg stiffness. We found that the leg stiffness curve consists of several segments in which the force-length relationship was similarly linear and the stiffness value was relatively constant; the phase divided by the leg stiffness curve corresponds to the phase divided by the CoM work rate curve. The results of this study may guide biomimetic control strategies for a wearable lower-extremity robot for the entire stance phase during stair climbing.
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http://dx.doi.org/10.1109/TNSRE.2022.3163130DOI Listing
April 2022

Bifidobacterium lactis Probio-M8 Adjuvant Treatment Confers Added Benefits to Patients with Coronary Artery Disease via Target Modulation of the Gut-Heart/-Brain Axes.

mSystems 2022 Apr 28;7(2):e0010022. Epub 2022 Mar 28.

Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural Universitygrid.411638.9, Hohhot, Inner Mongolia, China.

Accumulating evidence suggests that gut dysbiosis may play a role in cardiovascular problems like coronary artery disease (CAD). Thus, target steering the gut microbiota/metabolome via probiotic administration could be a promising way to protect against CAD. A 6-month randomized, double-blind, placebo-controlled clinical trial was conducted to investigate the added benefits and mechanism of the probiotic strain, Bifidobacterium lactis Probio-M8, in alleviating CAD when given together with a conventional regimen. Sixty patients with CAD were randomly divided into a probiotic group ( = 36; received Probio-M8, atorvastatin, and metoprolol) and placebo group ( = 24; placebo, atorvastatin, and metoprolol). Conventional treatment significantly improved the Seattle Angina Questionnaire (SAQ) scores of the placebo group after the intervention. However, the probiotic group achieved even better SAQ scores at day 180 compared with the placebo group ( < 0.0001). Moreover, Probio-M8 treatment was more conducive to alleviating depression and anxiety in patients ( < 0.0001 versus the placebo group, day 180), with significantly lower serum levels of interleukin-6 and low-density lipoprotein cholesterol ( < 0.005 and < 0.001, respectively). In-depth metagenomic analysis showed that, at day 180, significantly more species-level genome bins (SGBs) of Bifidobacterium adolescentis, Bifidobacterium animalis, Bifidobacterium bifidum, and Butyricicoccus porcorum were detected in the probiotic group compared with the placebo group, while the abundances of SGBs representing Flavonifractor plautii and Parabacteroides johnsonii decreased significantly among the Probio-M8 receivers ( < 0.05). Furthermore, significantly more microbial bioactive metabolites (e.g., methylxanthine and malonate) but less trimethylamine-N-oxide and proatherogenic amino acids were detected in the probiotic group than placebo group during/after intervention ( < 0.05). Collectively, we showed that coadministering Probio-M8 synergized with a conventional regimen to improve the clinical efficacy in CAD management. The mechanism of the added benefits was likely achieved via probiotic-driven modulation of the host's gut microbiota and metabolome, consequently improving the microbial metabolic potential and serum metabolite profile. This study highlighted the significance of regulating the gut-heart/-brain axes in CAD treatment. Despite recent advances in therapeutic strategies and drug treatments (e.g., statins) for coronary artery disease (CAD), CAD-related mortality and morbidity remain high. Active bidirectional interactions between the gut microbiota and the heart implicate that probiotic application could be a novel therapeutic strategy for CAD. This study hypothesized that coadministration of atorvastatin and probiotics could synergistically protect against CAD. Our results demonstrated that coadministering Probio-M8 with a conventional regimen offered added benefits to patients with CAD compared with conventional treatment alone. Our findings have provided a wide and integrative view of the pathogenesis and novel management options for CAD and CAD-related diseases.
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http://dx.doi.org/10.1128/msystems.00100-22DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9040731PMC
April 2022

Anionic Cyanine J-Type Aggregate Nanoparticles with Enhanced Photosensitization for Mitochondria-Targeting Tumor Phototherapy.

Angew Chem Int Ed Engl 2022 Mar 28:e202203093. Epub 2022 Mar 28.

Hubei Engineering Research Center for Biomaterials and Medical Protective Materials, Key Laboratory for Material Chemistry of Energy Conversion and Storage, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.

Cyanines have been widely used as the photosensitizers (PSs) in the biomedical field, but controlling their molecular aggregates in nanoparticles (NPs) remains a major challenge. Moreover, the impact of aggregate behaviors of cyanines on the photosensitization is still unclear. Herein, the first anionic cyanine PSs based on a tricyanofuran end group have been designed by achieving supramolecular J-type aggregates in NPs via counterion engineering. Our results indicate that J-type aggregates in NPs can not only bring significantly red-shifted emission, negatively charged surface, and high photostability, but also enable a significant 5-fold increase in singlet oxygen generation efficiency compared to that in the nonaggregate state, providing strong experimental evidence for the superiority of J-aggregates in enhancing photosensitization. Thus, combined with the mitochondria-targeting ability, the J-type aggregate NPs show remarkable in vivo antitumor phototheranostic efficacy, making them have a potential for clinical use.
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http://dx.doi.org/10.1002/anie.202203093DOI Listing
March 2022

Development and Application of a High-Resolution Melting Analysis with Unlabeled Probes for the Screening of Short-Tailed Sheep Heterozygotes.

Animals (Basel) 2022 Mar 21;12(6). Epub 2022 Mar 21.

School of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot 010010, China.

The short-tailed phenotype has long been considered one of the best traits for population genetic improvement in sheep breeding. In short-tailed sheep, not only is tail fat eliminated but also the pubic area is exposed due to the lack of a tail covering, giving them an advantage in reproduction. Recent studies have shown that two linked mutations in sheep at nucleotides 333 and 334 are associated with the short-tailed phenotype. In the population of short-tailed sheep, several heterozygous mutants of this gene are found. In our research, we used high-resolution melting (HRM) to identify homozygous and heterozygous genotypes in a flock of short-tailed sheep and compared the results with those of Sanger sequencing, which were identical. This demonstrates that our established HRM method, a rapid and inexpensive genotyping method, can be used to identify homozygous and heterozygous individuals in short-tailed sheep flocks.
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http://dx.doi.org/10.3390/ani12060792DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8944613PMC
March 2022

Modeling the effects of water diversion projects on surface water and groundwater interactions in the central Yangtze River basin.

Sci Total Environ 2022 Mar 17;830:154606. Epub 2022 Mar 17.

Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan 430074, China.

Due to the lack of the quantification of surface water (SW) and groundwater (GW) interaction, the chemicals transport and fate and wetland evolution are hard to predict under impact of both the natural condition and water diversion projects. To address this issue, a 3D regional numerical model is proposed in this study to analyze the effects of the South-to-North Water Diversion (SNWD) and Yangtze-Hanjiang Water Diversion (YHWD) projects on groundwater flow regimes and SW-GW interactions of Jianghan Plain in the central Yangtze River basin. The model results show that the Yangtze River and groundwater interactive pattern varied little, whereas the exchange capacity has been significantly affected by the SNWD but little affected by the YHWD. If only implemented SNWD project, the Hanjiang River and groundwater interactive pattern varied and the net exchange rate between the Hanjiang River and groundwater decreased by 69.3% compared to natural condition. Since YHWD was introduced to complement SNWD, the net exchange rate has been reduced by 25.3% compared with that under the only SNWD. SNWD and YHWD projects implementation caused the decrease of the groundwater level along the Yangtze River with the maximum value of 0.19 m but the increase of groundwater level along the Hanjiang River with the maximum rise reaching up to 0.78 m. This study provides the insights for quantification of GW-SW interaction at regional scale, which will benefiting for integrated water resource management and understanding contaminant reactive transport and wetland evolution in the central Yangtze River basin.
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http://dx.doi.org/10.1016/j.scitotenv.2022.154606DOI Listing
March 2022

Biomaterials reinforced MSCs transplantation for spinal cord injury repair.

Asian J Pharm Sci 2022 Jan 20;17(1):4-19. Epub 2021 Apr 20.

Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China.

Due to the complex pathophysiological mechanism, spinal cord injury (SCI) has become one of the most intractable central nervous system (CNS) diseases to therapy. Stem cell transplantation, mesenchymal stem cells (MSCs) particularly, appeals to more and more attention along with the encouraging therapeutic results for the functional regeneration of SCI. However, traditional cell transplantation strategies have some limitations, including the unsatisfying survival rate of MSCs and their random diffusion from the injection site to ambient tissues. The application of biomaterials in tissue engineering provides a new horizon. Biomaterials can not only confine MSCs in the injured lesions with higher cell viability, but also promote their therapeutic efficacy. This review summarizes the strategies and advantages of biomaterials reinforced MSCs transplantation to treat SCI in recent years, which are clarified in the light of various therapeutic effects in pathophysiological aspects of SCI.
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http://dx.doi.org/10.1016/j.ajps.2021.03.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8888140PMC
January 2022

Hypoxia-stimulated mesenchymal stem cell-derived exosomes loaded by adhesive hydrogel for effective angiogenic treatment of spinal cord injury.

Biomater Sci 2022 Mar 29;10(7):1803-1811. Epub 2022 Mar 29.

College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China.

Due to the limited efficacy of current clinical treatment strategies, functional recovery after traumatic spinal cord injury (SCI) remains a knotty problem to be solved. Apart from anti-inflammation and cell replenishing treatments, accumulating evidence implies that promoting angiogenesis would also potentially benefit tissue regeneration after SCI. In this research, inspired by the role of exosomes in cell-cell communication and exosomal alteration resulting from cells under stress, exosomes were engineered through hypoxia stimulation to mesenchymal stem cells and were proposed as an alternative for promoting angiogenesis in SCI therapy. Hypoxia-stimulated exosomes (hypo-Exo) were transplanted into the injured spinal cord encapsulation in a peptide-modified adhesive hydrogel for pro-angiogenic therapy of SCI. The adhesive peptide PPFLMLLKGSTR-modified hyaluronic acid hydrogel replenished the spinal cavity caused by SCI and achieved the local delivery of exosomes. The hypoxia-inducible factor 1-alpha content in hypo-Exo was significantly increased, resulting in the overexpression of vascular endothelial growth factor in the endothelial cells surrounding the transplant system. Ultimately, prominent angiogenesis and functional recovery after injury were demonstrated both and , indicating the immense potential of hydrogel-encapsulated hypo-Exo in treating central nervous system trauma and other ischemia diseases.
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http://dx.doi.org/10.1039/d1bm01722eDOI Listing
March 2022

Efficacy and Safety of Tirofiban in Clinical Patients With Acute Ischemic Stroke.

Front Neurol 2021 8;12:785836. Epub 2022 Feb 8.

Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, China.

Background: Intravenous thrombolysis and endovascular thrombectomy have been approved for acute ischemic stroke (AIS). However, only a minority of patients received these treatments in China. We aimed to evaluate the efficacy and safety of tirofiban in patients with AIS who were not undergoing early recanalization treatments.

Methods: Patients with mild-to-moderate stroke [National Institutes of Health Stroke Scale (NIHSS) score, 4-15] were enrolled in this study. Patients due to cardiogenic embolism were excluded. Eligible patients within 12 h from symptom onset were randomly assigned (1:1) to receive tirofiban (a loading dose of 0.4 μg/kg/min over 30 min and a maintenance dose of 0.1 μg/kg/min up to 48 h) followed by regular treatment or to receive regular treatment (aspirin at a dose of 100 mg per day for 90 days) (control). The primary outcome was the proportion of favorable functional outcomes at 90 days [defined as the modified Rankin Scale (mRS) score of 0-2]. The secondary outcomes included a shift in the distribution of the mRS scores at 90 days and the NIHSS score at 24 h and 7 days. The primary safety outcome was symptomatic intracranial hemorrhage (sICH) within 7 days after tirofiban treatment.

Results: A total of 380 eligible patients were randomly assigned to the tirofiban group ( = 190) or the control group ( = 190). The proportion of favorable functional outcomes was higher in the tirofiban group (79.1%) than that in the control group (67.8%) at 90 days [odds ratio (OR), 1.80; 95% CI, 1.12-2.90; = 0.0155]. An improvement was also observed in the overall distribution of the 90-day mRS scores (adjusted common OR, 2.31; 95% CI, 1.58-3.39; < 0.0001). Additionally, the median NIHSS score was lower in the tirofiban group than in the control group at 7 days (3 vs. 5, < 0.0001). Next, we observed that the occurrence of sICH did not differ between the two groups.

Conclusion: Our trial supports that tirofiban was safe and effective and might be a remedial treatment for patients with AIS who did not receive recanalization treatments.

Clinical Trial Registration: http://www.chictr.org.cn/, identifier: ChiCTR2000031297.
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http://dx.doi.org/10.3389/fneur.2021.785836DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8860815PMC
February 2022

Low-dose metformin targets the lysosomal AMPK pathway through PEN2.

Nature 2022 03 23;603(7899):159-165. Epub 2022 Feb 23.

State Key Laboratory for Cellular Stress Biology, Innovation Centre for Cell Signalling Network, School of Life Sciences, Xiamen University, Fujian, China.

Metformin, the most prescribed antidiabetic medicine, has shown other benefits such as anti-ageing and anticancer effects. For clinical doses of metformin, AMP-activated protein kinase (AMPK) has a major role in its mechanism of action; however, the direct molecular target of metformin remains unknown. Here we show that clinically relevant concentrations of metformin inhibit the lysosomal proton pump v-ATPase, which is a central node for AMPK activation following glucose starvation. We synthesize a photoactive metformin probe and identify PEN2, a subunit of γ-secretase, as a binding partner of metformin with a dissociation constant at micromolar levels. Metformin-bound PEN2 forms a complex with ATP6AP1, a subunit of the v-ATPase, which leads to the inhibition of v-ATPase and the activation of AMPK without effects on cellular AMP levels. Knockout of PEN2 or re-introduction of a PEN2 mutant that does not bind ATP6AP1 blunts AMPK activation. In vivo, liver-specific knockout of Pen2 abolishes metformin-mediated reduction of hepatic fat content, whereas intestine-specific knockout of Pen2 impairs its glucose-lowering effects. Furthermore, knockdown of pen-2 in Caenorhabditis elegans abrogates metformin-induced extension of lifespan. Together, these findings reveal that metformin binds PEN2 and initiates a signalling route that intersects, through ATP6AP1, the lysosomal glucose-sensing pathway for AMPK activation. This ensures that metformin exerts its therapeutic benefits in patients without substantial adverse effects.
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http://dx.doi.org/10.1038/s41586-022-04431-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8891018PMC
March 2022

A adenosine receptor inhibition ameliorates hypoxic-ischemic injury in neonatal mice via PKC/Erk/Creb/HIF-1α signaling pathway.

Brain Res 2022 05 16;1782:147837. Epub 2022 Feb 16.

School of Basic Medicine, Ningxia Medical University, Yinchuan 750004, Ningxia, PR China. Electronic address:

Periventricular leukomalacia (PVL), the dominant cerebral white matter injury disease, is induced by hypoxia-ischemia and inflammation in premature infants. The activation of A adenosine receptor (AAR) is shown to involve into inflammation, ischemia, and other typical stress reactions, but its exact function in PVL has not been clarified. We gained initial insight from PVL mouse model (P9) by the induction of hypoxia-ischemia with right carotid ligation followed by exposure to hypoxia and intraperitoneal (i.p.) injection of Lipopolysaccharide (LPS). The results showed that treatment of PSB-603, an AAR selective antagonist, greatly ameliorated cerebral ischemic injury by increasing bodyweights, reducing infarct volume, brain injury,inflammation andcontributing to long-term learning memory functionalrecoveryof the PVL mice. Meanwhile, PSB-603 treatment suppressed neurons apoptosis as characterized byreducing of Caspase-3 level, inhibited microglia activation and attenuated hypomyelination through promoting MBP expression and oligodendrocytes differentiation. AAR inhibition also augmented PKC expression, the activity of PKC downstream signaling molecules were then explored. Erk expression and Creb phosphorylation exhibited upregulation in PSB-603 treatment group compared with the control group. Hypoxia Inducible Factor-1α (HIF-1α), a direct target of hypoxia, which is a key regulator of adenosine signaling by binding to the AAR promoter to induce expression of AAR, was shown to be decreased by PSB-603. Taken together, AAR inhibition can ameliorate hypoxic-ischemic injury in PVL mice maybe through PKC/Erk/Creb/HIF-1α signaling pathway.
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http://dx.doi.org/10.1016/j.brainres.2022.147837DOI Listing
May 2022

Bone transport combined with bone graft and internal fixation versus simple bone transport in the treatment of large bone defects of lower limbs after trauma.

BMC Musculoskelet Disord 2022 Feb 17;23(1):157. Epub 2022 Feb 17.

Department of Orthopaedic Surgery, Hong Hui hospital, Xi'an Jiaotong University College of Medicine, Xi'an, 710054, Shaanxi, China.

Background: Bone transport has been successfully applied for the management of large segmental bone defects. However, its main shortcoming is the long-lasting consolidation period, which may cause lots of related complications. To overcome this shortcoming, we developed bone transport combined with bone graft and internal fixation technique. The purpose of this study was to compare the clinical effects of this modified technique with simple bone transport in the treatment of large segmental bone defects of lower limbs after trauma.

Methods: Eighty-four patients with large segmental bone defects treated in our institution from January 2014 to January 2017 were selected for retrospective study. A total of 77 cases were completely followed. Among them, 35 patients were treated by bone transport combined with bone graft and internal fixation technique (Group A), and 42 by simple bone transport technique (Group B). Patients with open injuries were classified according to Gustilo-Anderson (GA) classification. The general data of Group A and B were compared. The time in external fixator, total cure time and operation times of two groups were recorded. Ennecking score was used to evaluate the recovery of limb functions while self-rating anxiety scale (SAS) for the postoperative anxiety evaluation. In addition, the total complication incidence was compared between Group A and B.

Results: There was no significant difference in demographic data between Group A and B (p > 0.05). The time in external fixator of Group A and B was (4.8 ± 1.6) and (18.2 ± 3.9) months, respectively (p < 0.05). The total cure time was (17.6 ± 2.2) and (20.4 ± 2.8) months in Group A and B (p < 0.05). The number of operations in Group A and B was (4.9 ± 1.2) and (4.8 ± 1.0) (p > 0.05). Ennecking score of Group A and B was 84.7 and 75.7% (p < 0.05). SAS score and total complication incidence in Group A were significantly lower than those in Group B (p < 0.05).

Conclusions: The clinical effects of bone transport combined with bone graft and internal fixation technique were better than that of simple bone transport technique, including shorter time in external fixator, shorter total cure time, lower anxiety score and better limb functions.
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http://dx.doi.org/10.1186/s12891-022-05115-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8851812PMC
February 2022

Effects of runt-related transcription factor 2 () on the autophagy of rapamycin-treated osteoblasts.

Bioengineered 2022 03;13(3):5262-5276

Department of Orthopaedic Surgery, HongHui Hospital, Xi'an Jiaotong University, Xi'an, Shaan'xi Province, China.

Autophagy occurs throughout the development and maturation of bone tissues and various types of bone cells and plays a vital role in osteoporosis progression. This study aimed to explore the role of runt-related transcription factor 2 () in osteoblast autophagy and its related molecular mechanisms. MC3T3-E1 cells were treated with different concentrations of rapamycin, and their viability was determined using a cell counting Kit-8 (CCK-8). The cells were then transfected with si-RUNX2 and overexpression plasmids, and the viability of these rapamycin-treated cells was measured using CCK-8, while the expression of autophagy-related genes/proteins and osteoblast differentiation-related genes was determined using Western blotting and RT-qPCR. Finally, Alizarin red staining was used to observe osteoblast mineralization, and transmission electron microscopy was employed to detect autophagosomes in cells administered different treatments. Rapamycin significantly inhibited cell viability and promoted cell autophagy compared with the control ( < 0.05). Cells with RUNX2 knockdown and overexpression were successfully established. Further, overexpression was found to significantly enhance the viability and osteoblast mineralization of rapamycin-treated cells and suppress cell autophagy. overexpression also increased p-p38MAPK/p38MAPK levels and , and expression, and markedly downregulated Beclin-1, LC3-II/LC3-I, p62, ATG1, p-Beclin-1, and ATG5 levels ( < 0.05). However, the trends after knockdown opposed those observed after overexpression. may regulate osteoblast differentiation and autophagy by mediating autophagy-related and osteoblast differentiation-related genes/proteins, as well as the p38MAPK signaling pathway.
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http://dx.doi.org/10.1080/21655979.2022.2037881DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8973582PMC
March 2022

A MRI-based radiomics nomogram for evaluation of renal function in ADPKD.

Abdom Radiol (NY) 2022 04 13;47(4):1385-1395. Epub 2022 Feb 13.

Department of Radiology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, No.324, jingwuweiqi Road, Jinan, 250021, Shandong, China.

Objectives: This study is aimed to establish a fusion model of radiomics-based nomogram to predict the renal function of autosomal dominant polycystic kidney disease (ADPKD).

Methods: One hundred patients with ADPKD were randomly divided into training group (n = 69) and test group (n = 31). The radiomics features were extracted from T1-weighted fat suppression images (FS-T1WI) and T2-weighted fat suppression images (FS-T2WI). Decision tree algorithm was employed to build radiomics model to get radiomics signature. Then multivariate logistic regression analysis was used to establish the radiomics nomogram based on independent clinical factors, conventional MR imaging variables and radiomics signature. The receiver operating characteristic (ROC) analysis and Delong test were used to compare the performance of radiomics model and radiomics nomogram model, and the decision curve to evaluate the clinical application value of radiomics nomogram model in the evaluation of renal function in patients with ADPKD.

Results: Fourteen radiomics features were selected to establish radiomics model. Based on FS-T1WI and FS-T2WI sequences, the radiomics model showed good discrimination ability in training group and test group [training group: (AUC) = 0.7542, test group (AUC) = 0.7417]. The performance of radiomics nomogram model was significantly better than that of radiomics model in all data sets [radiomics model (AUC) = 0.7505, radiomics nomogram model (AUC) = 0.8435, p value = 0.005]. The analysis of calibration curve and decision curve showed that radiomics nomogram model had more clinical application value.

Conclusion: radiomics analysis of MRI can be used for the preliminary evaluation and prediction of renal function in patients with ADPKD. The radiomics nomogram model shows better prediction effect in renal function evaluation, and can be used as a non-invasive renal function prediction tool to assist clinical decision-making. Trial registration ChiCTR, ChiCTR2100046739. Registered 27 May 2021-retrospectively registered, http://www.ChiCTR.org.cn/showproj.aspx?proj=125955.
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http://dx.doi.org/10.1007/s00261-022-03433-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8930797PMC
April 2022

One pot purification and co-immobilization of His-tagged old yellow enzyme and glucose dehydrogenase for asymmetric hydrogenation.

Enzyme Microb Technol 2022 May 2;156:110001. Epub 2022 Feb 2.

School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, PR China. Electronic address:

In this study, a novel kind of Ni-NTA modified monodispersed SiO nanoflowers ([email protected] nanoflowers) were successfully synthesized. The obtained [email protected] nanoflowers were used to specifically adsorb and purify His-tagged old yellow enzyme (OYE1) and glucose dehydrogenase (GDH), which allows access to optically pure (3 S)- 3-methyl-cyclohexanone through asymmetric hydrogenation reaction, and forms a cofactor regeneration system. The protein loading amount on [email protected] nanoflowers was 40.17 mg/g and the activity recoveries of OYE1 and GDH were 81.53% and 79.68%, respectively. The effects of pH and temperature on the activity of free and co-immobilized enzymes were investigated, and the stability as well as reusability were also measured. Compared to free enzymes, the co-immobilized enzymes showed higher thermal and storage stability. The co-immobilized enzymes were applied to asymmetric reduction of CC bonds for the synthesis of a chiral center with excellent enantioselectivity (ee > 99%), and the conversion was 46.02% after 7 cycles. This work introduced a one-pot multi-enzyme purification and co-immobilization strategy to construct efficient cofactor regeneration system with high activity and stability.
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http://dx.doi.org/10.1016/j.enzmictec.2022.110001DOI Listing
May 2022

Open reduction and internal fixation of the tibial avulsion fracture of the posterior cruciate ligament: which is better, a hollow lag screw combined with a gasket or a homemade hook plate?

BMC Musculoskelet Disord 2022 Feb 11;23(1):143. Epub 2022 Feb 11.

Department of Orthopaedics and Trauma, Hong Hui Hospital, Xi'an Jiaotong University College of Medicine, No. 555, East Youyi Road, Xi'an, 710000, Shaanxi, China.

Objective: To compare the clinical results of homemade hook plates and hollow lag screws combined with spacers in the treatment of posterior cruciate tibial ligament avulsion fractures.

Materials And Methods: This was a retrospective clinical cohort study that included 64 patients with PCL tibial avulsion fractures. Thirty-two of them were fixed with a homemade hook plate (hook plate group), and 32 were fixed with a hollow lag screen combined with a gasket (hollow lag screen group). By reviewing the medical record data and follow-up results, the operation time, postoperative drainage, fracture healing time, surgical complications, knee mobility, recovery of joint function, and whether postoperative gastrocnemius muscle strength changed in the two groups were compared.

Results: All patients had successful wound and fracture healing. No adverse events, such as bone nonunion, infection, wound haematoma, or joint stiffness, occurred in either group. There were no patients with decreased gastrocnemius muscle strength in either group. Internal fixation failure occurred in 2 cases in the hollow lag screen group but not in the hook plate group. There were no significant differences between the two groups in terms of operative time, postoperative drainage, fracture healing time, knee mobility at the last follow-up, or Lysholm score.

Conclusion: It is safe and effective to use a homemade hook plate to fix PCL tibial avulsion fractures through an inverted L-shaped posterior medial approach. A homemade hook plate may have potential advantages over a hollow lag screen combined with gasket fixation.
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http://dx.doi.org/10.1186/s12891-022-05096-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8840316PMC
February 2022

Extended Ischemic Recovery After Implantation of Human Mesenchymal Stem Cell Aggregates Indicated by Sodium MRI at 21.1 T.

Transl Stroke Res 2022 Feb 7. Epub 2022 Feb 7.

National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA.

Extended therapeutic application remains a significant issue in the use of stem cell therapies to treat ischemic stroke. Along these lines, neurological recovery in a rodent model of ischemic stroke was evaluated following implantation of human mesenchymal stem cell aggregates (hMSC-agg), labeled with micron-sized particles of iron oxide, directly into the lateral ventricle contralateral to the ischemic lesion hemisphere. Longitudinally, disease progression and response to hMSC-agg therapy were assessed by H and Na magnetic resonance imaging (MRI) at 21.1 T to investigate cellular localization, migration, and recovery over an extended timeframe. MRI provides quantifiable metrics of tissue status through sodium distributions in addition to traditional proton imaging. Quantitative Na MRI revealed a significant decrease of sodium concentrations following hMSC aggregate implantation, indicating recovery of homeostasis. This result correlates positively with extended neurological recovery assessed by behavioral analysis and immunohistochemistry. These findings demonstrate the potential of implanted hMSC aggregate therapy to provide extended treatment for ischemic stroke, as well as the robustness of MRI for monitoring such approaches. This method potentially can be translated to a clinical setting for the assessment of extended cell therapy efficacy.
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http://dx.doi.org/10.1007/s12975-021-00976-4DOI Listing
February 2022

Feasibility of 3.5 mm C2 pedicle screws in children: A computerized tomography analysis.

Clin Anat 2022 Apr 8;35(3):347-353. Epub 2022 Feb 8.

Spine and Osteopathy Ward, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China.

There have been no studies with large sample sizes on growth of the pedicle of C2 in children. In the present study we measured the pedicle of C2 through computed tomography (CT) imaging in children aged less than 14 years and evaluated the suitability of the 3.5-mm screw for the pedicle in such children. The study was conducted on CT morphometric images of 420 children in our hospital between June 2018 and June 2020. The width (D1), length (D2), height (D3), inclination angle (α), and tail angle (β) of the C2 pedicle were measured. One-way analysis of variance and Student's t test were used for statistical analyses. The least-square method was used to analyze the curve fitting the trend of anatomical change in the pedicle. The largest degree of goodness of fit determined the best-fitting curve. The size of the pedicle of C2 increased with age. The median ranges of D1, D2, D3, α, and β were 3.312-5.431 mm, 11.732-23.645 mm, 3.597-8.038 mm, 32.583°-36.640°, and 24.867°-31.567°, respectively. The curves fitting the trends of D1 and D3 were power functions, whereas D2 was fitted by a logarithmic curve. However, no curve fitted α or β. A 3.5-mm screw can be placed in the pedicle of C2 in children aged more than 1 year. The growth and development trend of this pedicle can provide an anatomical reference for deciding on posterior cervical surgery and for selecting and designing pedicle screws for children.
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http://dx.doi.org/10.1002/ca.23837DOI Listing
April 2022

Design and Fabrication of a High-Frequency Micro-Convex Array Transducer for Small Animals Imaging.

IEEE Trans Ultrason Ferroelectr Freq Control 2022 Jan 24;PP. Epub 2022 Jan 24.

High-frequency convex array transducer, featuring both high spatial resolution and wide field of view, has been successfully developed for ophthalmic imaging. To further expand its application range to small animals imaging, this work develops a high-frequency micro-convex array transducer possessing smaller aperture size and wider scanning angle. This transducer featured 128 array elements arranged in a curvilinear 2-2 piezoelectric composite configuration, yielding a maximum view angle of 97.8°. The array was composed of two front matching layers, a non-conductive backing layer, and a customized flexible circuit which electrical connected array elements to coaxial cables. The center frequency and -6dB fractional bandwidth were about 18.14 MHz and 69.15%. The image of a tungsten wire phantom resulted in approximately 62.9 lm axial resolution and 121.3 lm lateral resolution. The image of the whole kidney of a rat, as well as its internal arteries was acquired in-vivo, demonstrating the imaging capability of the proposed high-frequency micro-convex array transducers for small animals imaging applications.
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http://dx.doi.org/10.1109/TUFFC.2022.3146309DOI Listing
January 2022

Hybrid, ultra-deep metagenomic sequencing enables genomic and functional characterization of low-abundance species in the human gut microbiome.

Gut Microbes 2022 Jan-Dec;14(1):2021790

Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot, China.

A large number of microbial genomes have already been identified from the human gut microbiome, but the understanding of the role of the low-abundance species at the individual level remains challenging, largely due to the relatively shallow sequencing depth used in most studies. To improve genome assembling performance, a HiSeq-PacBio hybrid, ultra-deep metagenomic sequencing approach was used to reconstruct metagenomic-assembled genomes (MAGs) from 12 fecal samples. Such approach combined third-generation sequencing with ultra-deep second-generation sequencing to improve the sequencing coverage of the low-abundance subpopulation in the gut microbiome. Our study generated a total of 44 megabase-scale scaffolds, achieving four single-scaffolds of complete (circularized, no gaps) MAGs (CMAGs) that were the first circular genomes of their species. Moreover, 475 high-quality MAGs were assembled across all samples. Among them, 234 MAGs were currently uncultured, including 24 MAGs that were not found in any public genome database. Additionally, 287 and 77 MAGs were classified as low-abundance (0.1-1%) and extra-low-abundance (<0.1%) gut species in each individual, respectively. Our results also revealed individual-specific genomic features in the MAG profiles, including microbial genome growth rate, selective pressure, and frequency of chromosomal mobile genetic elements. Finally, thousands of extrachromosomal mobile genetic elements were identified from the metagenomic data, including 5097 bacteriophages and 79 novel plasmid genomes. Overall, our strategy represents an important step toward comprehensive genomic and functional characterization of the human gut microbiome at an individual level.
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http://dx.doi.org/10.1080/19490976.2021.2021790DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8786330PMC
February 2022
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