Effects of L-theanine on intestinal morphology, barrier function, and MAPK signaling pathways in diquat-challenged piglets.

This study aimed to explore the protective effects of L-theanine supplementation on the diquat-challenged weaned piglets. A total of 160 weaned piglets were randomly divided into 4 groups using a 2 × 2 two-factor design, there were 4 replicates per group and 10 pigs per replicate. Piglets were fed diets (with 1000 mg/kg L-theanine addition or not), then challenged with diquat or saline on day 7. 21 days after challenge, two pigs from each replicate were selected for sample collection. Results showed that supplement with 1000 mg/kg L-theanine down-regulated the diarrhea rate, serum D-lactate level, tumor necrosis factor-α, and phosphorylation of extracellular regulated protein kinases (ERK1/2), p38 mitogen-activated protein kinase (MAPK), and c-Jun N-terminal kinase (JNK) signaling in pigs without diquat challenge (p < 0.05). While for diquat-challenged piglets, L-theanine addition increased average daily gain, jejunum villus height, and interferon-γ level (p < 0.05). Meanwhile, L-theanine addition decreased the diarrhea rates and mortality, serum D-lactate level, and phosphorylation of ERK and JNK in diquat-challenged pigs (p < 0.05). These results demonstrate that L-theanine pretreatment could alleviate diquat-induced oxidative stress and improve intestinal barrier function in diquat-challenged weaned piglets, which can be attributed to suppression of MAPK phosphorylation signaling pathways.

Effects of myonectin on porcine intramuscular adipocyte differentiation and exogenous free fatty acid utilization.

As an important factor secreted by skeletal muscle, myonectin can regulate lipid metabolism and energy metabolism, but its role in the utilization of peripheral free fatty acids (FFAs) by porcine intramuscular fat cells remains to be further investigated. In this study, porcine intramuscular adipocytes were treated with recombinant myonectin and palmitic acid (PA), either alone or in combination, and then were examined for their uptake of exogenous FFAs, intracellular lipid synthesis and catabolism, and mitochondrial oxidation of fatty acids. The results showed that myonectin decreased the area of lipid droplets in intramuscular adipocytes (p < 0.05) and significantly increased (p < 0.05) the expression levels of hormone-sensitive lipase (HSL) and lipoprotein lipase (LPL). Moreover, myonectin can up-regulate the expression of p38 mitogen-activated protein kinase (p38 MAPK). Myonectin significantly promoted the uptake of peripheral FFAs (p < 0.01), improved (p < 0.05) the expression of fatty transport protein 1 (FATP1) and fatty acid binding protein 4 (FABP4) in intramuscular adipocytes. Myonectin also significantly increased (p < 0.05) the expression levels of fatty acid oxidation markers: transcription factor (TFAM), uncoupling protein-2 (UCP2) and oxidative respiratory chain marker protein complex I (NADH-CoQ) in mitochondria of intramuscular adipocytes. In summary, myonectin promoted the absorption, transport, and oxidative metabolism of exogenous FFAs in mitochondria, thereby inhibiting lipid deposition in porcine intramuscular adipocytes.

A systemic review on Liubao tea: A time-honored dark tea with distinctive raw materials, process techniques, chemical profiles, and biological activities.

Liubao tea (LBT) is a unique microbial-fermented tea that boasts a long consumption history spanning 1500 years. Through a specific post-fermentation process, LBT crafted from local tea cultivars in Liubao town Guangxi acquires four distinct traits, namely, vibrant redness, thickness, aging aroma, and purity. The intricate transformations that occur during post-fermentation involve oxidation, degradation, methylation, glycosylation, and so forth, laying the substance foundation for the distinctive sensory traits. Additionally, LBT contains multitudinous bioactive compounds, such as ellagic acid, catechins, polysaccharides, and theabrownins, which contributes to the diverse modulation abilities on oxidative stress, metabolic syndromes, organic damage, and microbiota flora. However, research on LBT is currently scattered, and there is an urgent need for a systematical recapitulation of the manufacturing process, the dominant microorganisms during fermentation, the dynamic chemical alterations, the sensory traits, and the underlying health benefits. In this review, current research progresses on the peculiar tea varieties, the traditional and modern process technologies, the substance basis of sensory traits, and the latent bioactivities of LBT were comprehensively summarized. Furthermore, the present challenges and deficiencies that hinder the development of LBT, and the possible orientations and future perspectives were thoroughly discussed. By far, the productivity and quality of LBT remain restricted due to the reliance on labor and experience, as well as the incomplete understanding of the intricate interactions and underlying mechanisms involved in processing, organoleptic quality, and bioactivities. Consequently, further research is urgently warranted to address these gaps.

The web-based multiplex PCR primer design software Ultiplex and the associated experimental workflow: up to 100- plex multiplicity.

BACKGROUND: A large number of variants have been employed in various medical applications, such as providing medication instructions, disease susceptibility testing, paternity testing, and tumour diagnosis. A high multiplicity PCR will outperform other technologies because of its lower cost, reaction time and sample consumption. To conduct a multiplex PCR with higher than 100 plex multiplicity, primers need to be carefully designed to avoid the formation of secondary structures and nonspecific amplification between primers, templates and products. Thus, a user-friendly, highly automated and highly user-defined web-based multiplex PCR primer design software is needed to minimize the work of primer design and experimental verification. RESULTS: Ultiplex was developed as a free online multiplex primer design tool with a user-friendly web-based interface ( http://ultiplex.igenebook.cn ). To evaluate the performance of Ultiplex, 294 out of 295 (99.7%) target primers were successfully designed. A total of 275 targets produced qualified primers after primer filtration, and 271 of those targets were successfully clustered into one compatible PCR group and could be covered by 108 primers. The designed primer group stably detected the rs28934573(C > T) mutation at lower than a 0.25% mutation rate in a series of samples with different ratios of HCT-15 and HaCaT cell line DNA. CONCLUSION: Ultiplex is a web-based multiplex PCR primer tool that has several functions, including batch design and compatibility checking for the exclusion of mutual secondary structures and mutual false alignments across the whole genome. It offers flexible arguments for users to define their own references, primer Tm values, product lengths, plex numbers and tag oligos. With its user-friendly reports and web-based interface, Ultiplex will provide assistance for biological applications and research involving genomic variants.

Quantum limited timing jitter of soliton molecules in a mode-locked fiber laser.

Soliton molecules in mode-locked lasers are expected to be ideal self-organization patterns, which warrant stability and robustness against perturbations. However, recent ultra-high resolution optical cross-correlation measurements uncover an intra-molecular timing jitter, even in stationary soliton molecules. In this work, we found that the intra-molecular timing jitter has a quantum origin. Numerical simulation indicates that amplified spontaneous emission (ASE) noise induces a random quantum diffusion for soliton pulse timing, which cannot be compensated by soliton binding mechanism. By suppressing indirectly coupled timing jitter at close-to-zero cavity dispersion, a record-low 350 as rms intra-soliton-molecular jittering is obtained from an Er-fiber laser in experiment. This work provides insight into the fundamental limits for the instability of multi-soliton patterns.

Injectable In Situ Self-Cross-Linking Hydrogels Based on Hemoglobin, Carbon Quantum Dots, and Sodium Alginate for Real-Time Detection of Wound Bacterial Infection and Efficient Postoperative Prevention of Tumor Recurrence.

Postoperative wound repair of solid tumors resection, which is afflicted by the complex tumor microenvironment (TME) and associated with the bacterial infection, is worsening and demands prompt solutions. Meanwhile, the tumor recurrence is frequently seen during the subsequent treatment due to intraoperative bleeding. For effective postoperative cancer therapy, nanoscale carriers occur as innovative and sensitive tools for monitoring the wound state, avoiding bacterial infection, and restraining tumor recurrence. Herein, a multifunctional sodium alginate (SA) hydrogel immobilizing hemoglobin (Hb) and pH-sensitive fluorescent changing carbon quantum dots (CQDs) is rationally designed. The multifunctionalization of obtained alginate@hemoglobin@CQDs hydrogel (SA@Hb@CQDs) simultaneously consists of detection, hemostasis, and chemodynamic therapy (CDT) with monitoring of wound pH based on CQDs, stanching triggered from SA hydrogel, and Fenton reaction induced by Hb. We demonstrated that SA@Hb@CQDs can stop bleeding quickly, collect wound status information in real-time, and avert bacterial infection as well as inhibit local tumor recurrence effectively. Therefore, our work provides a promising combination approach for postoperative tumor therapy.

Analysis of the Curative Effect of the Anterior Approach to the Lower Cervical Spine for Cervicothoracic Spinal Tuberculosis.

BACKGROUND: The purpose of this study was to explore the clinical effect of the anterior approach to the lower cervical spine for cervicothoracic spinal tuberculosis (CTSTB). METHODS: A total of 8 patients (6 males and 2 females) with CTSTB diagnosed by imaging examination and γ-interferon test, underwent the first stage lesion removal, bone grafting and internal fixation through the anterior approach to the lower cervical spine, were studied. Then, the clinical efficacy was evaluated using statistical analysis based on the materials about the Cobb angle of kyphosis, visual analog scale (VAS), Frankel grade, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). RESULTS: All patients' age ranged from 28 to 64 years (mean 46.2 ±â€Š16.3). The mean operation time was 145 minutes (range 90-180 mins), intraoperative blood loss was 425 mL (range 200-1000 mL), and the average bone fusion time was 7.4 months. Postoperative neurological function of Frankel grading was significantly improved compared with that of preoperative. At final follow-up, the kyphosis angle was significantly decreased to 10 ±â€Š2.1°, the mean VAS score was 1.6 ±â€Š0.9 showing significant improvement, ESR and CRP returned to normal. The incidence of complications within 3 months after surgery was 25%, and the incidence of complications directly related to surgery was 12.5% (cerebrospinal fluid leakage). CONCLUSION: On the basis of familiarity with the anatomical structure and combining with the experience of the surgeon, the anterior approach to the lower cervical spine can be an effective treatment method for CTSTB.

Adaptive chaotic MIMO radar based on DPMM clustering and Kalman filtering technique.

A novel scheme to optimize the adaptive transmit waveform of chaotic multiple-input multiple-output (MIMO) radar is developed. The main objective of this work is to achieve high ability in target discrimination by using a Dirichlet process mixture model (DPMM)-based clustering method based on nonparametric Bayesian theory and to improve the capability of target detection by minimizing the mean square error of radar channel response via Kalman filtering (KF) technique. The two stages are the discrimination of multiple range-extended targets and the optimization of the adaptive chaos-based waveform for transmission. The adaptive chaotic MIMO waveform optimization scheme overcomes the problem of target discrimination and detection in an intelligent transportation system, where there is a need for extracting the feature of target information achieved from vehicle-mounted sensor. As the number of iterations increases, simulation experiments demonstrate better target discrimination capability provided by the proposed DPMM-KF technique as compared with the traditional waveform design method. In addition, the proposed DPMM-KF technique leads to improved target detection probability and receiver operating characteristics in the interference environment.

Smart Scanning Ion-Conductance Microscopy Imaging Technique Using Horizontal Fast Scanning Method.

To solve extended acquisition time issues inherent in the conventional hopping-scanning mode of scanning ion-conductance microscopy (SICM), a new transverse-fast scanning mode (TFSM) is proposed. Because the transverse motion in SICM is not the detection direction and therefore presents no collision problem, it has the ability to move at high speed. In TSFM, the SICM probe gradually descends in the vertical/detection direction and rapidly scans in the transverse/nondetection direction. Further, the highest point that decides the hopping height of each scanning line can be quickly obtained. In conventional hopping mode, however, the hopping height is artificially set without a priori knowledge and is typically very large. Consequently, TFSM greatly improves the scanning speed of the SICM imaging system by effectively reducing the hopping height of each pixel. This study verifies the feasibility of this novel scanning method via theoretical analysis and experimental study, and compares the speed and quality of the scanning images obtained in the TFSM with that of the conventional hopping mode. The experimental results indicate that the TFSM method has a faster scanning speed than other SICM scanning methods while maintaining the quality of the images. Therefore, TFSM provides the possibility to quickly obtain high-resolution three-dimensional topographical images of extremely complex samples.

Long-Term Outcomes after Performing Tympanoplasty without Mastoidectomy for Active and Inactive Noncholesteatomatous Chronic Otitis Media.

OBJECTIVE: This study aimed to assess long-term outcomes after performing tympanoplasty without mastoidectomy (TWOM) for active and inactive noncholesteatomatous chronic otitis media (COM) and to estimate the optimal time for surgery. METHODS: The patients were placed into an active ear group (group A) and an inactive ear group (group B). All patients were followed up for 5 years after TWOM. RESULTS: Ninety-two cases among 113 achieved dry ears in half a month to 1 month. The tympanic pressure gradually improved 3-6 months after the operation. A total of 69/72 ears achieved dry ears in the active ear group, and 37 ears had effective hearing improvement. In all, 40/41 ears achieved dry ears in the inactive ear group, and 20 ears had effective hearing improvement. There was no difference in the recurrence rate or hearing improvement in the two groups. CONCLUSION: With good quality control of the surgical treatment of TWOM, there are no differences in long-term outcomes in noncholesteatomatous COM in different chronic infection conditions.

A microsatellite diversity analysis and the development of core-set germplasm in a large hulless barley (Hordeum vulgare L.) collection.

BACKGROUND: Clarifying genetic diversity in a large germplasm resource plays important roles in experimental designs that provides flexible utility in fundamental research and breeding in crops. However, the work is limited due to small collections of barley that are insufficient representatives. RESULTS: In the present study, we collected 562 hulless barley (Hordeum vulgare L.) accessions with worldwide geographic origins and evaluated their genetic variability and relatedness based on 93 simple sequence repeat (SSR) markers. In an integrated analysis of the population structure, analysis of molecular variance (AMOVA) and pairwise F ST, the 562 barley accessions exhibited a strong stratification that allowed for them to be divided into two major subpopulations (p1 and p2) and an admixture subpopulation, with 93, 408 and 61 accessions, respectively. In a neutral test, considerable proportions of SSR alleles expressed the strong non-neutrality in specific subpopulations (44 and 37), which are probably responsible for population differentiation. To reduce the diversity redundancy in large barley collections, we delicately selected a core set of 200 barley accessions as a tradeoff between diversity and representativeness in an easily handled population. In comparing the 562 barley accessions, the core barley set accounted for 96.2% of allelic diversity and 93% to 95% of phenotypic variability, whereas it exhibited a significant enhancement in minor allelic frequencies, which probably benefit association mapping in the barley core set. CONCLUSIONS: The results provided additional insight into the genetic structure in a large barley germplasm resource, from which an easily manageable barley core set was identified, demonstrating the great potential for discovering key QTLs and ultimately facilitating barley breeding progress.

Association between CYP1B1 gene polymorphisms and risk factors and susceptibility to laryngeal cancer.

BACKGROUND: The aim of this study was to investigate the association between polymorphism of the cytochrome P450 1B1 (CYP1B1) gene, a metabolic enzyme gene, and the susceptibility to laryngeal cancer among the Chinese Han population. MATERIAL/METHODS: In a case-control study, we investigated polymorphisms in the CYP1B1 gene (rs10012, rs1056827, and rs1056836) with a real-time quantitative polymerase chain reaction (PCR) assay (TaqMan). The study was conducted with 300 Chinese Han patients with laryngeal cancer and 300 healthy Chinese Han subjects in a control group. We also studied the interactions between genetic polymorphism and risk factors such as smoking and alcohol consumption in the pathogenesis of laryngeal cancer. RESULTS: There were statistically significant differences in the distributions of the rs1056827 and rs1056836 genotypes between the 2 groups. Regarding rs1056827, carriers of the T allele had a significantly higher risk of laryngeal cancer than the G-allele carriers (OR=1.4339, 95% CI: 1.1268-1.8247; P=0.0034). The difference was still statistically significant after adjusting for factors such as age, sex, smoking, and drinking (adjusted OR=1.743, 95% CI: 1.124-3.743, P<0.001). However, regarding rs1056836, the G allele carriers had a significantly lower risk of laryngeal cancer than the C allele carriers (OR=0.5557, 95% CI: 0.3787-0.8154; P=0.0027). The difference was statistically significant even after adjusting for factors such as age, sex, smoking, and drinking (adjusted OR=0.5641, 95% CI: 0.3212-0.8121, P=0.001). Subjects who carry the C-T-C haplotype have a significantly increased incidence of laryngeal cancer. We also found that CYP1B1 rs1056827 polymorphism had synergistic effects with smoking or alcohol consumption regarding the risk of laryngeal cancer. CONCLUSIONS: CYP1B1 gene polymorphism is closely related to the onset of laryngeal cancer. There is a mutually synergistic effect between smoking, alcohol consumption, and CYP1B1 gene polymorphisms regarding laryngeal cancer.

Stephaochratidin A, a Rare Stephacidin-Asperochratide Hybrid with Ferroptosis Inhibitory Activity from the Deep-Sea-Derived Aspergillus ochraceus.

One rare stephacidin-asperochratide hybrid, stephaochratidin A (1), was isolated from the deep-sea-derived Aspergillus ochraceus MCCC 3A00521. The relative structure of 1 was determined by comprehensive analyses of its 1D and 2D NMR data as well as HRESIMS data. And the absolute configuration was unambiguously assigned by ECD calculations and the X-ray single-crystal diffraction analysis. Plausible biosynthetic pathway of 1 was proposed. Stephaochratidin A (1) exhibited significant ferroptosis inhibitory activity with the EC50 value of 15.4 µM by downregulating HMOX-1 expression and lipid peroxidation.

hnRNPU is required for spermatogonial stem cell pool establishment in mice.

The continuous regeneration of spermatogonial stem cells (SSCs) underpins spermatogenesis and lifelong male fertility, but the developmental origins of the SSC pool remain unclear. Here, we document that hnRNPU is essential for establishing the SSC pool. In male mice, conditional loss of hnRNPU in prospermatogonia (ProSG) arrests spermatogenesis and results in sterility. hnRNPU-deficient ProSG fails to differentiate and migrate to the basement membrane to establish SSC pool in infancy. Moreover, hnRNPU deletion leads to the accumulation of ProSG and disrupts the process of T1-ProSG to T2-ProSG transition. Single-cell transcriptional analyses reveal that germ cells are in a mitotically quiescent state and lose their unique identity upon hnRNPU depletion. We further show that hnRNPU could bind to Vrk1, Slx4, and Dazl transcripts that have been identified to suffer aberrant alternative splicing in hnRNPU-deficient testes. These observations offer important insights into SSC pool establishment and may have translational implications for male fertility.

K8sSim: A Simulation Tool for Kubernetes Schedulers and Its Applications in Scheduling Algorithm Optimization.

In recent years, Kubernetes (K8s) has become a dominant resource management and scheduling system in the cloud. In practical scenarios, short-running cloud workloads are usually scheduled through different scheduling algorithms provided by Kubernetes. For example, artificial intelligence (AI) workloads are scheduled through different Volcano scheduling algorithms, such as GANG_MRP, GANG_LRP, and GANG_BRA. One key challenge is that the selection of scheduling algorithms has considerable impacts on job performance results. However, it takes a prohibitively long time to select the optimal algorithm because applying one algorithm in one single job may take a few minutes to complete. This poses the urgent requirement of a simulator that can quickly evaluate the performance impacts of different algorithms, while also considering scheduling-related factors, such as cluster resources, job structures and scheduler configurations. In this paper, we design and implement a Kubernetes simulator called K8sSim, which incorporates typical Kubernetes and Volcano scheduling algorithms for both generic and AI workloads, and provides an accurate simulation of their scheduling process in real clusters. We use real cluster traces from Alibaba to evaluate the effectiveness of K8sSim, and the evaluation results show that (i) compared to the real cluster, K8sSim can accurately evaluate the performance of different scheduling algorithms with similar CloseRate (a novel metric we define to intuitively show the simulation accuracy), and (ii) it can also quickly obtain the scheduling results of different scheduling algorithms by accelerating the scheduling time by an average of 38.56×.

Advances in volumetric bioprinting.

The three-dimensional (3D) bioprinting technologies are suitable for biomedical applications owing to their ability to manufacture complex and high-precision tissue constructs. However, the slow printing speed of current layer-by-layer (bio)printing modality is the major limitation in biofabrication field. To overcome this issue, volumetric bioprinting (VBP) is developed. VBP changes the layer-wise operation of conventional devices, permitting the creation of geometrically complex, centimeter-scale constructs in tens of seconds. VBP is the next step onward from sequential biofabrication methods, opening new avenues for fast additive manufacturing in the fields of tissue engineering, regenerative medicine, personalized drug testing, and soft robotics, etc. Therefore, this review introduces the printing principles and hardware designs of VBP-based techniques; then focuses on the recent advances in VBP-based (bio)inks and their biomedical applications. Lastly, the current limitations of VBP are discussed together with future direction of research.

Asymmetric gene expression and cell-type-specific regulatory networks in the root of bread wheat revealed by single-cell multiomics analysis.

BACKGROUND: Homoeologs are defined as homologous genes resulting from allopolyploidy. Bread wheat, Triticum aestivum, is an allohexaploid species with many homoeologs. Homoeolog expression bias, referring to the relative contribution of homoeologs to the transcriptome, is critical for determining the traits that influence wheat growth and development. Asymmetric transcription of homoeologs has been so far investigated in a tissue or organ-specific manner, which could be misleading due to a mixture of cell types. RESULTS: Here, we perform single nuclei RNA sequencing and ATAC sequencing of wheat root to study the asymmetric gene transcription, reconstruct cell differentiation trajectories and cell-type-specific gene regulatory networks. We identify 22 cell types. We then reconstruct cell differentiation trajectories that suggest different origins between epidermis/cortex and endodermis, distinguishing bread wheat from Arabidopsis. We show that the ratio of asymmetrically transcribed triads varies greatly when analyzing at the single-cell level. Hub transcription factors determining cell type identity are also identified. In particular, we demonstrate that TaSPL14 participates in vasculature development by regulating the expression of BAM1. Combining single-cell transcription and chromatin accessibility data, we construct the pseudo-time regulatory network driving root hair differentiation. We find MYB3R4, REF6, HDG1, and GATAs as key regulators in this process. CONCLUSIONS: Our findings reveal the transcriptional landscape of root organization and asymmetric gene transcription at single-cell resolution in polyploid wheat.

Association between maternal allergic rhinitis and asthma on the prevalence of atopic disease in offspring.

BACKGROUND: Asthma is a common co-morbidity of allergic rhinitis (AR). The prevalence of these two allergic diseases has increased in China and has been shown to cluster in families independently. This study evaluated the association between maternal AR (presenting with or without asthma) and the allergic conditions in offspring. METHODS: Women (n = 592) diagnosed with AR were recruited for this study; 379 patients presented with AR and 213 presented with both AR and asthma. Total serum IgE levels and nasal eosinophil counts were analyzed and correlated with disease presentation. RESULTS: The prevalence of allergic conditions in offspring of mothers diagnosed with AR and asthma was significantly higher than the prevalence observed in children born to mothers presenting with AR only. Maternal total serum IgE and eosinophil counts were predictive of atopy in offspring. Children born to mothers presenting with persistent moderate-to-severe AR had the highest risk of developing atopic conditions (OR 6.26, 95% CI 3.26-12.02). Maternal age of 25-30 years at delivery was also associated with a higher risk for the allergic disease in offspring compared to maternal age of 36-40 (OR 2.13, 95% CI 1.31-3.47). CONCLUSIONS: The severity of maternal AR, asthma co-morbidity, elevated serum IgE levels and nasal eosinophilia were all associated with an increased risk of offspring developing allergic conditions. Children born to older mothers were protected against developing atopic disease.

Experimental and numerical investigation of TVOC concentrations and ventilation dilution in enclosed train cabin.

Air pollution in trains is an important factor threatening human health, which has attracted more and more attention in the worldwide public health researches. In this study, one cabin of a fully enclosed train was taken as an example to conduct experimental and numerical research on pollution level and distribution characteristic of total volatile organic compound (TVOC). The results show that when the average emission rate under daily environmental conditions was taken as the reference, TVOC concentration in the cabin exceeded the limit level of Chinese Indoor Air Quality Standard by more than 4 times. The obvious pollutants accumulative phenomenon could be found at bottoms and corners under the action of airflow. Setting air inlets at the roof of the train, mean age of air ranged from 30 s to 50 s in the breathing area. The concentration of pollutants was the lowest at 2.5-5 m from the center point of the cabin structure, and the ventilation efficiency was the highest. The introduction of clean fresh air could effectively eliminate pollutants. When the complete displacement ventilation rates were 51.4 h-1 and 28.6 h-1, the removal efficiency of pollutants was about 0.85 and 0.48 mg/m3 per minute, respectively. This study was helpful to the improvement and optimization design of air quality and ventilation mode in trains.

Surgical Management for Posterior Atlantoaxial Dislocation without Fracture and Atlantoaxial Dynamic Test to Confirm the Integrity of the Transverse Ligament: A Case Report.

BACKGROUND: Traumatic posterior atlantoaxial dislocation (PAAD) without fracture of the odontoid process is a rare injury. Closed reduction by skull traction under C-arm fluoroscopic guidance and open reduction have been reported previously for the treatment of PAAD. OBJECTIVE: To report a rare case of PAAD without fracture treated by closed manual reduction and posterior fixation. To provide a new method-atlantoaxial dynamic test-for confirming the integrity of the transverse ligament after reduction and evaluate the ideal treatment strategy for traumatic PAAD without fracture of the odontoid process or rupture of the transverse ligament. METHOD: A 54-year-old woman was riding in the passenger seat when her vehicle was rear-ended by a car. X-ray and computed tomography (CT) scans were used to diagnose PAAD without a related fracture. Closed manual reduction under C-arm fluoroscopy was performed after applying general anesthesia via sober intubation, and the integrity of the transverse ligament was confirmed by the atlantoaxial dynamic test with C-arm fluoroscopy. Then, pedicle screw internal fixation via the posterior approach was applied to maintain atlantoaxial stability. RESULTS: The procedure was performed uneventfully, and the patient was able to move out of bed on the first day after surgery with Philadelphia cervical gear. During a 2-year follow-up period, imaging data demonstrated no instability of the atlantoaxial complex. CONCLUSION: Closed manual reduction under C-arm fluoroscopy is an easy and effective method for PAAD. The integrity of the transverse ligament can be confirmed by C-arm fluoroscopy through the atlantoaxial dynamic test after reduction. Pedicle screw internal fixation via the posterior approach can provide sufficient stability.