Netrin-1-engineered endothelial cell exosomes induce the formation of pre-regenerative niche to accelerate peripheral nerve repair.

The formation of vascular niche is pivotal during the early stage of peripheral nerve regeneration. Nevertheless, the mechanisms of vascular niche in the regulation of peripheral nerve repair remain unclear. Netrin-1 (NTN1) was found up-regulated in nerve stump after peripheral nerve injury (PNI). Herein, we demonstrated that NTN1-high endothelial cells (NTN1+ECs) were the critical component of vascular niche, fostering angiogenesis, axon regeneration, and repair-related phenotypes. We also found that NTN1+EC-derived exosomes (NTN1 EC-EXO) were involved in the formation of vascular niche as a critical role. Multi-omics analysis further verified that NTN1 EC-EXO carried a low-level expression of let7a-5p and activated key pathways associated with niche formation including focal adhesion, axon guidance, phosphatidylinositol 3-kinase-AKT, and mammalian target of rapamycin signaling pathway. Together, our study suggested that the construction of a pre-regenerative niche induced by NTN1 EC-EXO could establish a beneficial microenvironment for nerve repair and facilitate functional recovery after PNI.

Real time monitoring peripheral nerve function with ICG and BDA-ICG by NIR-II fluorescence imaging.

Neuroanatomical tract tracers are important for studying axoplasmic transport and the complex interconnections of the nervous system. Though traditional fluorescent tracers are widely used, they have several prominent drawbacks when imaging, including low resolutions and low tissue penetrations and inability to be supervised dynamically within a long peripheral nerve during the long term. Here, we explored the potential of ICG as a neural tracer for axoplasmic transport and for the first time demonstrated that ICG could be used to detect transport function within peripheral nerve by near-infrared region II (NIR-II) imaging. On basis of this finding, a novel bi-directional neural tracer biotinylated dextran amine-indocyanine green (BDA-ICG) was prepared and characterized with better long-term stability and higher nerve-to-background ratio than ICG in vivo, and successfully imaged the injured peripheral nerve from the healthy one within 24 h. Our results show that BDA-ICG are promising neural tracers and clinically available dyes with NIR-II emission tail characteristics as ICG.

Peripheral nervous system lymphatic vessels: A simple delivery route to promote nerve regeneration.

The structural and functional features of lymphatic vessels in the peripheral nervous system (pLVs) is still unclear. Here, we clarify the existence of pLVs in rats, PROX1-EGFP transgenic mice and human, and exhibit a clear three-dimensional structure for helping understand its structural features. Moreover, two specific phenotypes of lymphatics endothelial cells (Rnd1Hi LECs and Ccl21Hi LECs) in peripheral nerves are well characterized by single-cell sequencing. Subsequently, the ability of trans-lymphatic delivery to peripheral nerves via pLVs has been dynamically demonstrated. After peripheral nerve injury (PNI), extensive lymphangiogenesis occurs in the lesion area and further enhances the efficiency of retrograde lymphatic-nerve transport. In PNI animal models, subcutaneously footpad-injected exosomes are efficiently delivered to sciatic nerve via pLVs which can promote nerve regeneration. The trans-lymphatic delivery to peripheral nerves via pLVs can subtly bypass BNB which provides an easy and alternative delivery route for PNI treatment.

Isofraxidin attenuates dextran sulfate sodium-induced ulcerative colitis through inhibiting pyroptosis by upregulating Nrf2 and reducing reactive oxidative species.

BACKGROUND: Ulcerative colitis (UC), a non-specific gastrointestinal disease, is commonly managed with aminosalicylic acids and immunosuppressive agents to control inflammation and relieve symptoms, despite frequent relapses. Isofraxidin is a coumarin compound extracted from traditional Chinese medicine, exhibiting anti-inflammatory and antioxidant properties; however, its alleviating effect on UC remains unclear. Therefore, we investigated the mechanism of isofraxidin in lipopolysaccharide (LPS)-induced cell inflammation in human intestinal epithelial cell (HIEC) and human colorectal adenocarcinoma cells (Caco-2), as well as in dextran sulfate sodium (DSS)-induced UC in mice. METHODS: We established colitis models in HIEC and Caco-2 cells and mice with LPS and DSS, respectively. Additionally, NLRP3 knockout mice and HIEC cells transfected with NLRP3 silencing gene and ML385 illustrated the role of isofraxidin in pyroptosis and oxidative stress. Data from cells and mice analyses were subjected to one-way analysis of variance or a paired t-test. RESULTS: Isofraxidin significantly alleviated LPS-induced cell inflammation and reduced lactic dehydrogenase release. Isofraxidin also reversed DSS- or LPS-induced pyroptosis in vivo and in vitro, increasing the expression of pyroptosis-related proteins. Moreover, isofraxidin alleviated oxidative stress induced by DSS or LPS, reducing reactive oxidative species (ROS), upregulation nuclear factor erythroid 2-related factor 2 (Nrf2), and promoting its entry into the nucleus. Mechanistically, ML385 reversed the inhibitory effect of isofraxidin on ROS and increased pyroptosis. CONCLUSION: Isofraxidin can inhibit pyroptosis through upregulating Nrf2, promoting its entry into the nucleus, and reducing ROS, thereby alleviating DSS-induced UC. Our results suggest isofraxidin as a promising therapeutic strategy for UC treatment.

Predictors for quality of life in older adults: network analysis on cognitive and neuropsychiatric symptoms.

BACKGROUND: Quality of life (QoL) of older adults has become a pivotal concern of the public and health system. Previous studies found that both cognitive decline and neuropsychiatric symptoms (NPS) can affect QoL in older adults. However, it remains unclear how these symptoms are related to each other and impact on QoL. Our aim is to investigate the complex network relationship between cognitive and NPS symptoms in older adults, and to further explore their association with QoL. METHODS: A cross-sectional study was conducted in a sample of 389 older individuals with complaints of memory decline. The instruments included the Neuropsychiatric Inventory, the Mini Mental State Examination, and the 36-item Short Form Health Survey. Data was analyzed using network analysis and mediation analysis. RESULTS: We found that attention and agitation were the variables with the highest centrality in cognitive and NPS symptoms, respectively. In an exploratory mediation analysis, agitation was significantly associated with poor attention (ß = -0.214, P < 0.001) and reduced QoL (ß = -0.137, P = 0.005). The indirect effect of agitation on the QoL through attention was significant (95% confidence interval (CI) [-0.119, -0.035]). Furthermore, attention served as a mediator between agitation and QoL, accounting for 35.09% of the total effect. CONCLUSIONS: By elucidating the NPS-cognition-QoL relationship, the current study provides insights for developing rehabilitation programs among older adults to ensure their QoL.

Exosome-based regenerative rehabilitation: A novel ice breaker for neurological disorders.

Neurological disorders affect a large population, often leading to different levels of disability and resulting in decreased quality of life. Due to the limited recovery obtained from surgical procedures and other medical approaches, a large number of patients with prolonged dysfunction receive neurorehabilitation protocols to improve their neural plasticity and regeneration. However, the poor neural regeneration ability cannot effectively rebuild the tissue integrity and neural functional networks; consequently, the prognoses of neurorehabilitation remain undetermined. To increase the chances of neural regeneration and functional recovery for patients with neurological disorders, regenerative rehabilitation was introduced with combined regenerative medicine and neurorehabilitation protocols to repair neural tissue damage and create an optimized biophysical microenvironment for neural regeneration potential. With the deepening of exosome research, an increasing number of studies have found that the systemic therapeutic effects of neurorehabilitation approaches are mediated by exosomes released by physically stimulated cells, which provides new insight into rehabilitative mechanisms. Meanwhile, exosome therapy also serves as an alternative cell-free therapy of regenerative medicine that is applied in partnership with neurorehabilitation approaches and formulates exosome-based neurological regenerative rehabilitation. In this study, we review the current state of exosome-associated neurorehabilitation. On the one hand, we focus on presenting the varied mediating effects of exosomes in neurorehabilitation protocols of specific neurological pathologies; on the other hand, we discuss the diverse combinations of exosome therapies and neurorehabilitation approaches in the field of neurological regenerative rehabilitation, aiming to increase the awareness of exosome research and applications in the rehabilitation of neurological disorders.

Fast and versatile electrostatic disc microprinting for piezoelectric elements.

Nanoparticles, films, and patterns are three critical piezoelectric elements with widespread applications in sensing, actuations, catalysis and energy harvesting. High productivity and large-area fabrication of these functional elements is still a significant challenge, let alone the control of their structures and feature sizes on various substrates. Here, we report a fast and versatile electrostatic disc microprinting, enabled by triggering the instability of liquid-air interface of inks. The printing process allows for fabricating lead zirconate titanate free-standing nanoparticles, films, and micro-patterns. The as-fabricated lead zirconate titanate films exhibit a high piezoelectric strain constant of 560 pm V-1, one to two times higher than the state-of-the-art. The multiplexed tip jetting mode and the large layer-by-layer depositing area can translate into depositing speeds up to 109 µm3 s-1, one order of magnitude faster than current techniques. Printing diversified functional materials, ranging from suspensions of dielectric ceramic and metal nanoparticles, to insulating polymers, to solutions of biological molecules, demonstrates the great potential of the electrostatic disc microprinting in electronics, biotechnology and beyond.

Fluorescence imaging of peripheral nerve function and structure.

Peripheral nerve injuries are common and can cause catastrophic consequences. Although peripheral nerves have notable regenerative capacity, full functional recovery is often challenging due to a number of factors, including age, the type of injury, and delayed healing, resulting in chronic disorders that cause lifelong miseries and significant financial burdens. Fluorescence imaging, among the various techniques, may be the key to overcome these restrictions and improve the prognosis because of its feasibility and dynamic real-time imaging. Intraoperative dynamic fluorescence imaging allows the visualization of the morphological structure of the nerve so that surgeons can reduce the incidence of medically induced injury. Axoplasmic transport-based neuroimaging allows the visualization of the internal transport function of the nerve, facilitating early, objective, and accurate assessment of the degree of regenerative repair, allowing early intervention in patients with poor recovery, thereby improving prognosis. This review briefly discusses peripheral nerve fluorescent dyes that have been reported or could potentially be employed, with a focus on their role in visualizing the nerve's function and anatomy.

Autophagy induced by PP121 alleviates MSU crystal-induced acute gouty arthritis via inhibition of the NLRP3 inflammasome.

Acute gouty arthritis (AGA) is a frequent self-limiting inflammatory condition produced by the deposition of monosodium urate (MSU) crystals in the joints and periarticular tissues of patients with hyperuricemia. However, no effective interventional measures currently exist for AGA. Pyroptosis, a kind of pro-inflammatory programmed cell death, plays a crucial role in MSU crystal-induced inflammation and represents a potential treatment target for AGA. Therefore, we determined the therapeutic benefits and mechanism of PP121, a pyroptosis-related compound, on AGA. First, we injected an MSU crystal solution intra-articularly into the left foot pad of C57BL/6 mice to create an AGA mouse model. Subsequent treatment with PP121 substantially decreased tissue damage, pro-inflammatory cytokine release, and inflammatory cell infiltration caused by MSU crystals in the ankle joint. Consistent with these observations, the beneficial effects of PP121 on AGA were cancelled in Beclin1+/-(Becn1+/-) mice. Furthermore, after PP121 treatment, super-resolution microscopy revealed a strong relationship between lysosome-connected membrane protein/light chain 3 positive vesicles and the nucleotide-binding domain of leucine-rich family pyrin domain-containing 3 (NLPR3), demonstrating that PP121 promotes phagocytosis of the NLPR3 inflammasome. In summary, PP121-mediated autophagy can improve degradation of the NLRR3 inflammasome in AGA, which suggests the therapeutic potential of PP121 in AGA.

Dipeptidase­2 is a prognostic marker in lung adenocarcinoma that is correlated with its sensitivity to cisplatin.

Lung cancer accounts for the highest percentage of cancer morbidity and mortality worldwide, and lung adenocarcinoma (LUAD) is the most prevalent subtype. Although numerous therapies have been developed for lung cancer, patient prognosis is limited by tumor metastasis and more effective treatment targets are urgently required. In the present study, gene expression profiles were extracted from the Gene Expression Omnibus database and mRNA expression data were downloaded from The Cancer Genome Atlas database. In addition, TIMER 2.0 database was used to analyze the expression of genes in normal and multiple tumor tissues. Protein expression was confirmed using the Human Protein Atlas database and LUAD cell lines, sphere formation assay, western blotting, and a xenograft mouse model were used to confirm the bioinformatics analysis. Dipeptidase­2 (DPEP2) expression was significantly decreased in LUAD and was negatively associated with prognosis. DPEP2 overexpression substantially inhibited epithelial­mesenchymal transition (EMT) as well as LUAD cell metastasis, and limited the expression of the cancer stem cell transformation markers, CD44 and CD133. In addition, DPEP2 improved LUAD sensitivity to cisplatin by inhibiting EMT; this was verified in vitro and in vivo. These data indicated that DPEP2 upregulates E­cadherin, thereby regulating cell migration, cancer stem cell transformation, and cisplatin resistance, ultimately affecting the survival of patients with LUAD. Overall, the findings of the present suggest that DPEP2 is important in the development of LUAD and can be used both as a prognostic marker and a target for future therapeutic research.

Differential expression and correlation of immunoregulation related piRNA in rheumatoid arthritis.

Background: Although PIWI-interacting RNAs (piRNAs) have recently been associated with germline development and many human diseases, their expression pattern and relationship in autoimmune diseases remain indistinct. This study aimed to investigate the presence and correlation of piRNAs in rheumatoid arthritis (RA). Methods: We first analyzed the expression profile of piRNAs using small RNA sequencing in peripheral leukocytes of three new-onset untreated RA patients and three healthy controls (HCs). We then selected piRNAs related to immunoregulation by bioinformatics analysis and verified them in 42 new-onset RA patients and 81 HCs by RT-qPCR. Furthermore, a receiver operating characteristic curve was generated to quantify the diagnostic performance of these piRNAs. A correlation analysis was conducted to observe the link between piRNA expression and RA clinical characteristics. Results: A total of 15 upregulated and 9 downregulated piRNAs among 1,565 known piRNAs were identified in peripheral leukocytes of RA patients. Dysregulated piRNAs were enriched in numerous pathways related to immunity. After selection and validation, two immunoregulation piRNAs (piR-hsa-27620 and piR-hsa-27124) were significantly elevated in RA patients and have good abilities to distinguish patients from controls, which have the potential to serve as biomarkers. PIWI and other proteins implicated in the piRNA pathway were also associated with RA.

CC-115 Mediates GSDME-Dependent Pyroptosis in Lung Adenocarcinoma Through the Akt/Bax Pathway.

Chemotherapeutic agents remain the first-line treatment for solid tumors, including lung cancer, but chemotherapy resistance is hampering global efforts to treat this disease. CC-115 is a novel antitumoral compound used in phase I clinical trials. However, it is unclear whether CC-115 is effective against lung adenocarcinoma (LUAD). In the present study, we found that CC-115 induced lytic cell death in A549 and H1650 tumor cells via swelling of cells and formation of large bubbles on the plasma membrane that closely resembled those typical of pyroptosis, a type of programmed cell death linked to chemotherapy. We demonstrated that CC-115 exerts antitumor effects in LUAD through gasdermin E (GSDME)-mediated pyroptosis by acting as a dual inhibitor of DNA-PK and mTOR. CC-115 can inhibit Akt phosphorylation, impairing its inhibitory effect on Bax, thereby inducing pyroptosis via the Bax-mitochondrial intrinsic pathway. CC-115-induced pyroptosis was abrogated by treatment with the Akt activator SC79 or by depletion of Bax. Importantly, CC-115 significantly upregulated the expression of Bax and GSDME-N in a xenograft mouse model, with a reduction in tumor size. Our results revealed that CC-115 suppresses tumor growth by inducing GSDME-mediated pyroptosis through the Akt/Bax-mitochondrial intrinsic pathway, indicating CC-115 as a promising therapeutic agent for LUAD.

Endothelial cell-derived exosomes boost and maintain repair-related phenotypes of Schwann cells via miR199-5p to promote nerve regeneration.

BACKGROUND: Schwann cells (SCs) respond to nerve injury by transforming into the repair-related cell phenotype, which can provide the essential signals and spatial cues to promote axonal regeneration and induce target reinnervation. Endothelial cells (ECs) contribute to intraneural angiogenesis contributing to creating a permissive microenvironment. The coordination between ECs and SCs within injury sites is crucial in the regeneration process, however, it still unclear. As the intercellular vital information mediators in the nervous system, exosomes have been proposed to take a significant role in regulating regeneration. Thus, the main purpose of this study is to determine the facilitative effect of ECs-derived exosomes on SCs and to seek the underlying mechanism. RESULTS: In the present study, we collected exosomes from media of ECs. We demonstrated that exosomes derived from ECs possessed the favorable neuronal affinity both in vitro and in vivo. Further research indicated that EC-exosomes (EC-EXO) could boost and maintain repair-related phenotypes of SCs, thereby enhancing axonal regeneration, myelination of regenerated axons and neurologically functional recovery of the injured nerve. MiRNA sequencing in EXO-treated SCs and control SCs indicated that EC-EXO significantly up-regulated expression of miR199-5p. Furthermore, this study demonstrated that EC-EXO drove the conversion of SC phenotypes in a PI3K/AKT/PTEN-dependent manner. CONCLUSION: In conclusion, our research indicates that the internalization of EC-EXO in SCs can promote nerve regeneration by boosting and maintaining the repair-related phenotypes of SCs. And the mechanism may be relevant to the up-regulated expression of miR199-5p and activation of PI3K/AKT/PTEN signaling pathway.

Current understanding of tandem spinal stenosis: epidemiology, diagnosis, and surgical strategy.

Tandem spinal stenosis (TSS) is defined as the concomitant occurrence of stenosis in at least two or more distinct regions (cervical, thoracic, or lumbar) of the spine and may present with a constellation of signs and symptoms. It has four subtypes, including cervico-lumbar, cervico-thoracic, thoraco-lumbar, and cervico-thoraco-lumbar TSS. The prevalence of TSS varies depending on the different subtypes and cohorts. The main aetiologies of TSS are spinal degenerative changes and heterotopic ossification, and patients with developmental spinal stenosis, ligament ossification, and spinal stenosis at any region are at an increased risk of developing TSS. The diagnosis of TSS is challenging. The clinical presentation of TSS could be complex, concealed, or severe, and these features may be confusing to clinicians, resulting in an incomplete or delayed diagnosis. Additionally, a consolidated diagnostic criterion for TSS is urgently required to improve consistency across studies and form a basis for establishing treatment guidelines. The optimal treatment option for TSS is still under debate; areas of controversies include choice of the decompression range, choice between simultaneous or staged surgical patterns, and the order of the surgeries. The present study reviews publications on TSS, consolidates current awareness on prevalence, aetiologies, potential risk factors, diagnostic dilemmas and criteria, and surgical strategies based on TSS subtypes. This is the first review to include thoracic spinal stenosis as a candidate disorder in TSS and aims at providing the readers with a comprehensive overview of TSS.

Increased susceptibility of irradiated mice to Aspergillus fumigatus infection via NLRP3/GSDMD pathway in pulmonary bronchial epithelia.

BACKGROUND: Aspergillus fumigatus infection is difficult to diagnose clinically and can develop into invasive pulmonary aspergillosis, which has a high fatality rate. The incidence of Aspergillus fumigatus infection has increased die to widespread application of radiotherapy technology. However, knowledge regarding A. fumigatus infection following radiation exposure is limited, and the underlying mechanism remains unclear. In this study, we established a mouse model to explore the effect of radiation on A. fumigatus infection and the associated mechanisms. METHODS: In this study, a mouse model of A. fumigatus infection after radiation was established by irradiating with 5 Gy on the chest and instilling 5 × 107/ml Aspergillus fumigatus conidia into trachea after 24 h to explore the effect and study its function and mechanism. Mice were compared among the following groups: normal controls (CON), radiation only (RA), infection only (Af), and radiation + infection (RA + Af). Staining analyses were used to detect infection and damage in lung tissues. Changes in protein and mRNA levels of pyroptosis-related molecules were assessed by western blot analysis and quantitative reverse transcription polymerase chain reaction, respectively. Protein concentrations in the serum and alveolar lavage fluid were also measured. An immunofluorescence colocalization analysis was performed to confirm that NLRP3 inflammasomes activated pyroptosis. RESULTS: Radiation destroyed the pulmonary epithelial barrier and significantly increased the pulmonary fungal burden of A. fumigatus. The active end of caspase-1 and gasdermin D (GSDMD) were highly expressed even after infection. Release of interleukin-18 (IL-18) and interleukin-1ß (IL-1ß) provided further evidence of pyroptosis. NLRP3 knockout inhibited pyroptosis, which effectively attenuated damage to the pulmonary epithelial barrier and reduced the burden of A. fumigatus. CONCLUSIONS: Our findings indicated that the activation of NLRP3 inflammasomes following radiation exposure increased susceptibility to A. fumigatus infection. Due to pyroptosis in lung epithelial cells, it resulted in the destruction of the lung epithelial barrier and further damage to lung tissue. Moreover, we found that NLRP3 knockout effectively inhibited the pyroptosis and reducing susceptibility to A. fumigatus infection and further lung damage. Overall, our results suggest that NLRP3/GSDMD pathway mediated-pyroptosis in the lungs may be a key event in this process and provide new insights into the underlying mechanism of infection. Video abstract.

LncRNA MALAT1 mediates osteogenic differentiation in osteoporosis by regulating the miR-485-5p/WNT7B axis.

Introduction: Accumulating evidence demonstrates that long non-coding RNAs (lncRNAs) are associated with the development of osteoporosis. Methods: This study aimed to investigate the effects of MALAT1 on osteogenic differentiation and cell apoptosis in osteoporosis. MALAT1 level, detected by RT-qPCR, was downregulated in hindlimb unloading (HU) mice and simulated microgravity (MG)-treated MC3T3-E1 cells. Moreover, osteogenic differentiation-related factor (Bmp4, Col1a1, and Spp1) levels were measured by RT-qPCR and Western blot. ALP activity was detected, and ALP staining was performed. Cell apoptosis was assessed by flow cytometry. Results: The results revealed that MALAT1 upregulated the expression of Bmp4, Col1a1, and Spp1, and enhanced ALP activity. Knockdown of MALAT1 suppressed their expression and ALP activity, suggesting that MALAT1 promoted osteogenic differentiation. Additionally, MALAT1 inhibited apoptosis, increased Bax and caspase-3 levels, and decreased Bcl-2 level. However, knockdown of MALAT1 had opposite results. In MG cells, MALAT1 facilitated osteogenic differentiation and suppressed apoptosis. Furthermore, miR-485-5p was identified as a target of MALAT1, and WNT7B was verified as a target of miR-485-5p. Overexpression of miR-485-5p rescued the promotion of osteogenic differentiation and the inhibition of apoptosis induced by MALAT1. Knockdown of WNT7B abolished the facilitation of osteogenic differentiation and the suppression of apoptosis induced by downregulation of miR-485-5p. Discussion: In conclusion, MALAT1 promoted osteogenic differentiation and inhibited cell apoptosis through the miR-485-5p/WNT7B axis, which suggested that MALAT1 is a potential target to alleviate osteoporosis.

Prenatal diagnosis of isolated lateral facial cleft by ultrasonography and three-dimensional printing: A case report.

BACKGROUND: Lateral facial clefts are atypical with a low incidence in the facial cleft spectrum. With the development of ultrasonography (US) prenatal screening, such facial malformations can be detected and diagnosed prenatally rather than at birth. Although three-dimensional US (3DUS) can render the fetus' face via 3D reconstruction, the 3D images are displayed on two-dimensional screens without field depth, which impedes the understanding of untrained individuals. In contrast, a 3D-printed model of the fetus' face helps both parents and doctors develop a more comprehensive understanding of the facial malformation by creating more interactive aspects. Herein, we present an isolated lateral facial cleft case that was diagnosed via US combined with a 3D-printed model. CASE SUMMARY: A 31-year-old G2P1 patient presented for routine prenatal screening at the 22nd wk of gestation. The coronal nostril-lip section of two-dimensional US (2DUS) demonstrated that the fetus' bilateral oral commissures were asymmetrical, and left oral commissure was abnormally wide. The left oblique-coronal section showed a cleft at the left oral commissure which extended to the left cheek. The results of 3DUS confirmed the cleft. Furthermore, we created a model of the fetal face using 3D printing technology, which clearly presented facial malformations. The fetus was diagnosed with a left lateral facial cleft, which was categorized as a No. 7 facial cleft according to the Tessier facial cleft classification. The parents terminated the pregnancy at the 24th wk of gestation after parental counseling. CONCLUSION: In the diagnostic course of the current case, in addition to the traditional application of 2D and 3DUS, we created a 3D-printed model of the fetus, which enhanced diagnostic evidence, benefited the education of junior doctors, improved parental counseling, and had the potential to guide surgical planning.

Clinical Therapy of Metastatic Spinal Tumors.

Metastatic spinal tumors (MST) have high rates of morbidity and mortality. MST can destroy the vertebral body or compress the nerve roots, resulting in an increased risk of pathological fractures and intractable pain. Here, we elaborately reviewed the currently available therapeutic options for MST according to the following four aspects: surgical management, minimally invasive therapy (MIT), radiation therapy, and systemic therapy. In particular, these aspects were classified and introduced to show their developmental process, clinical effects, advantages, and current limitations. Furthermore, with the improvement of treatment concepts and techniques, we discovered the prevalent trend toward the use of radiation therapy and MIT in clinic therapies. Finally, the future directions of these treatment options were discussed. We hoped that along with future advances and study will lead to the improvement of living standard and present status of treatment in patients with MST.

Postoperative discal pseudocyst and its similarities to discal cyst: A case report.

BACKGROUND: Postoperative discal pseudocyst (PDP) is a rare condition that presents after surgery for lumbar disc herniation. Due to the lack of information, the diagnosis and treatment of PDP remain controversial. Herein, we report a PDP case that occurred following percutaneous endoscopic lumbar discectomy and received conservative treatment. Additionally, we review all the published literature regarding PDP and propose our hypothesis regarding PDP pathology. CASE SUMMARY: A 23-year-old man presented with a relapse of low back pain and numbness in his left lower extremity after undergoing percutaneous endoscopic lumbar discectomy for lumbar disc herniation. Repeat magnetic resonance imaging demonstrated a cystic lesion at the surgical site with communication with the inner disc. The patient was diagnosed as having PDP. The patient received conservative treatment, which resulted in rapid improvement and spontaneous regression of the lesion, and had a favorable outcome in follow-up. CONCLUSION: PDP and discal cyst (DC) exhibit similarities in both histological and epidemiological characteristics, which indicates the same pathological origin of PDP and DC. The iatrogenic annular injury during discectomy might accelerate the pathological progression of DC. For patients with mild to moderate symptoms, conservative treatment can lead to great improvement, even inducing spontaneous regression. However, surgical cystectomy is necessary in patients with neurological deficits and where conservative treatment is ineffective.