Incidence of Spontaneous Resorption of Lumbar Disc Herniation: A Meta-analysis.

STUDY DESIGN: A meta-analysis. OBJECTIVE: This study aimed to analyze the incidence of spontaneous resorption of lumbar disk herniation (LDH) after conservative treatment. SUMMARY OF BACKGROUND DATA: The resorption of intervertebral disks has been more frequently reported, but there is a lack of reference to the probability of resorption. METHODS: We strictly refer to the standard established in the PRISMA (Preferred Reporting Items for a Systematic Review and Meta-analysis) statement, comprehensively searched electronic databases using the terms related to the spontaneous resorption of LDH. Two reviewers independently evaluated the potential studies, extracted, and analyzed the enrolled data. RESULTS: Thirty-one studies with 2233 patients who received conservative treatment were included for this analysis. We found that the pooled overall incidence of disk resorption was 70.39%, 87.77% for disk sequestration, 66.91% for disk extrusion, 37.53% for disk protrusion, and 13.33% for disk bugle, respectively. The resorption incidence in of 25%≤ reduction of disk herniation (RDH) 50%, RDH≥50%, and RDH=100% were 40.19%, 43.62, and 36.89%. The resorption incidence was 66.98% in Japan, 61.66% in the United States, 83.52% in Korea, 60.68% in China, 78.30% in the UK, 56.70% in Italy, and 83.68% in Turkey, respectively. Subgroup analysis showed that there was no significant difference in resorption incidence among prospective, retrospective studies and randomized controlled trials (P=0.77), and there was no significant difference in evaluation method among qualitative and quantitative studies (P=0.05). CONCLUSIONS: The existing evidence shows that the overall resorption incidence of LDH was 70.39%, the resorption incidence of ruptured LDH is higher than that of contained LDH. There are significant differences in the resorption incidence among countries. The resorption process mainly occurred within 6 months of conservative treatment.

Role of regulatory T cells in spinal cord injury.

Spinal cord injury is an intricate process involving a series of multi-temporal and multi-component pathological events, among which inflammatory response is the core. Thus, it is crucial to find a way to prevent the damaging effects of the inflammatory response. The research has found that Treg cells can suppress the activation, proliferation, and effector functions of many parenchymal cells by multiple mechanisms. This review discusses how Treg cells regulate the inflammatory cells to promote spinal cord recovery. These parenchymal cells include macrophages/microglia, oligodendrocytes, astrocytes, and others. In addition, we discuss the adverse role of Treg cells, the status of treatment, and the prospects of cell-based therapies after spinal cord injury. In conclusion, this review provides an overview of the regulatory role of Treg cells in spinal cord injury. We hope to offer new insights into the treatment of spinal cord injury.

ROS-activated MAPK/ERK pathway regulates crosstalk between Nrf2 and Hif-1α to promote IL-17D expression protecting the intestinal epithelial barrier under hyperoxia.

Reactive oxygen species (ROS) damage to the intestinal barrier is a side effect of prolonged hyperoxia therapy in neonates, which impairs growth and development of the intestine and promotes intestinal diseases. However, the research on clinical prevention and treatment is lacking. Therefore, we investigated the molecular mechanisms of the neonate intestinal response against hyperoxia-derived ROS to find targets for intestinal barrier damage prevention. Human intestinal epithelial cells were incubated under hyperoxia (85% oxygen) to build an in vitro model. ROS and the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway were inhibited to detect the MAPK/ERK pathway, nuclear factor erythroid factor 2-related factor 2 (Nrf2), hypoxia-inducible factor-1α (Hif-1α), and interleukin-17D (IL-17D) expression. Nrf2 was inhibited to detect Hif-1α and IL-17D expression. Hif-1α was inhibited to detect Nrf2, IL-17D, and tight junction proteins expression and apoptosis. Cells were treated with human recombinant IL-17D to detect TNF-α, IL-1ß, IL-10, and tight junction proteins expression. ROS, Nrf2, Hif-1α, and IL-17D were upregulated and the MAPK/ERK pathway was activated under hyperoxia. But ROS inhibition downregulated the MAPK/ERK pathway, Nrf2, Hif-1α, and IL-17D. MAPK/ERK pathway inhibition downregulated Nrf2, Hif-1α, and IL-17D. Nrf2 inhibition downregulated Hif-1α and IL-17D. Hif-1α inhibition downregulated Nrf2, IL-17D, tight junction proteins, and exacerbated apoptosis. The recombinant IL-17D downregulated TNF-α, IL-1ß, but upregulated IL-10 and tight junction proteins. We concluded that Hyperoxia-generated ROS activated the MAPK/ERK pathway to regulate Nrf2, Hif-1α, and IL-17D expression. Nrf2 and Hif-1α were interdependent and promoted IL-17D. Importantly, Hif-1α and IL-17D expression protected the intestinal epithelial barrier.

IL-17D affects the chemokines and chemokine receptors of intestinal epithelial cells under hyperoxia.

IL-17D is a new member of the IL-17 family. Currently, it is believed that IL-17D can directly act on immune cells or may indirectly modulate immune responses by regulating cytokine expression. Herein, we hypothesized that IL-17D regulates the expression of chemokines in intestinal epithelial cells, in turn modulating the immune response within intestinal mucosa under hyperoxia. To explore this notion, newborn rats were divided into a hyperoxia group (85 % O2) and control group (21 % O2). Small intestinal tissues were obtained from neonatal rats at 3, 7, 10, and 14 days. Similarly, intestinal epithelial cells were treated by hyperoxia (85 % O2) as the hyperoxia group or were incubated under normal oxygen (21 % O2) as the control group. Finally, intestinal epithelial cells subjected to hyperoxia were treated with recombinant IL-17D and IL-17D antibodies for 24, 48, and 72 h. Immunohistochemistry, western blot, and reverse transcription-quantitative polymerase chain reaction were used to detect the expression levels of chemokines and chemokine receptors in intestinal tissues of newborn rats and intestinal epithelial cells. We found that hyperoxia affected chemokine expression both in vivo and in vitro. Under hyperoxia, IL-17D promoted the expression of CCL2, CCL25, CCL28, and CCR9 in intestinal epithelial cells while downregulating CCR2, CCR5, CCL5, and CCL20. Our findings provide a basis for further study on the effects of hyperoxia-induced intestinal inflammation and intestinal injury.

Predictive factors for residual leg numbness after decompression surgery for lumbar degenerative diseases.

BACKGROUND: The purpose of this study is to evaluate the change patterns of leg numbness (LN) after lumbar decompression surgery (LDS), and to find the predictive factors that affect the recovery of numbness. METHODS: Patients who underwent LDS in our institution between August 2020 and July 2021 were prospectively enrolled in this study, and were followed by a 12-month follow-up. The degree of LN, leg pain (LP) and the disability were assessed using the visual analog scale (VAS) and oswestry disability index (ODI). RESULTS: A total of 314 patients finished the 12-month follow-up. The preoperative mean VAS-LN score was 3.49 ± 2.44, which decreased to 1.91 ± 1.30 at 3 months, to 1.29 ± 0.97 at 6 months and to 1.26 ± 0.96 at 12 months after surgery. The preoperative mean VAS-LP score was 6.05 ± 1.30, which decreased to 2.00 ± 0.86 at 3 months, to 1.02 ± 0.80 at 6 months, and to 0.49 ± 0.71 at 12 months after surgery. The preoperative mean ODI score was 27.90 ± 7.08, which decreased to 9.73 ± 3.09 at 3 months, to 6.72 ± 2.98 at 6 months, and to 4.57 ± 2.76 at 12 months after surgery. Via multivariate logistic regression analysis, only preoperative VAS-LN score (p < 0.001*) was identified as a significantly independent predictive factor for residual LN after operation. CONCLUSION: Clinically significant improvement in LN was observed in the majority of patients within 6 months after LDS, and the improvement of VAS-LN was slower than the VAS-LP. High pre-operative VAS-LN score can independently predict the presence of residual LN after surgery at 12-month follow up.

Minimally invasive posterior cervical foraminotomy versus anterior cervical discectomy and fusion for cervical radiculopathy: a meta-analysis.

With the recent development of minimally invasive techniques, minimally invasive posterior cervical foraminotomy (MIS-PCF) has become increasingly popular as a minimally invasive method to treat cervical radiculopathy. However, there are still controversies about whether MIS-PCF is superior to anterior cervical discectomy and fusion (ACDF). The purpose of this study is to evaluate the therapeutic effects of MIS-PCF and ACDF on unilateral cervical radiculopathy without myelopathy. We searched PubMed, Embase, the Cochrane Library, and Scopus comprehensively using the terms related to MIS-PCF. Two reviewers independently evaluated the potential studies, and extracted and analyzed the data of operation time, hospital stay, neck disability index (NDI) score, visual analog scale for neck pain (VAS-neck) and arm pain (VAS-arm) scores, reoperation rate, and complications. Seven studies with 1175 patients were included. The study population was 53.5% male, with a mean age of 48.9. MIS-PCF presented a significantly shorter postoperative hospitalization time compared to ACDF, while the operation time, complication/reoperation rate, and VAS-arm, VAS-neck, and NDI scores were comparable between the two cohorts. In North America, the average cost of MIS-PCF is lower than ACDF. Thus, we suggest that MIS-PCF is an alternative to ACDF for selected patients.

Bisphosphates for Osteoporosis: A Bibliometric Analysis of the Most Cited Articles.

Osteoporosis has become a major public health problem and bisphosphates treatment for osteoporosis is a rapidly developing research field. Every year, plenty of studies devoted to the treatment of osteoporosis are published, giving clinicians a new perspective on bisphosphates treatment for osteoporosis. However, the quality of the scientific papers in this area is unclear. The aim of the present study was to characterize the 100 top-cited articles regarding bisphosphates treatment for osteoporosis. This analysis provides an accessible list for practitioners of endocrinology, pharmacy, epidemiology, imaging, surgery, and scientific research to identify the most frequently cited literature and better understand the future direction.

A Bibliometric Analysis of Personal Protective Equipment and COVID-19 Researches.

COVID-19, which occurred at the end of December 2019, has evolved into a global public health threat and affects every aspect of human life. COVID-19's high infectivity and mortality prompted governments and the scientific community to respond quickly to the pandemic outbreak. The application of personal protective equipment (PPE) is of great significance in overcoming the epidemic situation. Since the discovery of severe acute respiratory coronavirus 2 (SARS-CoV-2), bibliometric analysis has been widely used in many aspects of the COVID-19 epidemic. Although there are many reported studies about PPE and COVID-19, there is no study on the bibliometric analysis of these studies. The citation can be used as an indicator of the scientific influence of an article in its field. The aim of this study was to track the research trends and latest hotspots of COVID-19 in PPE by means of bibliometrics and visualization maps.

1,25(OH)2D3 Mitigates Oxidative Stress-Induced Damage to Nucleus Pulposus-Derived Mesenchymal Stem Cells through PI3K/Akt Pathway.

Intervertebral disc degeneration (IVDD) is one of the main causes of low back pain. The local environment of the degenerated intervertebral disc (IVD) increases oxidative stress and apoptosis of endogenous nucleus pulposus-derived mesenchymal stem cells (NPMSCs) and weakens its ability of endogenous repair ability in degenerated IVDs. A suitable concentration of 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) has been certified to reduce oxidative stress and cell apoptosis. The current study investigated the protective effect and potential mechanism of 1,25(OH)2D3 against oxidative stress-induced damage to NPMSCs. The present results showed that 1,25(OH)2D3 showed a significant protective effect on NPMSCs at a concentration of 10-10 M for 24 h. Protective effects of 1,25(OH)2D3 were also exhibited against H2O2-induced NPMSC senescence, mitochondrial dysfunction, and reduced mitochondrial membrane potential. The Annexin V/PI apoptosis detection assay, TUNEL assay, immunofluorescence, western blot, and real-time quantitative polymerase chain reaction assay showed that pretreatment with 1,25(OH)2D3 could alleviate H2O2-induced NPMSC apoptosis, including the apoptosis rate and the expression of proapoptotic-related (Caspase-3 and Bax) and antiapoptotic-related (Bcl-2) proteins. The intracellular expression of p-Akt increased after pretreatment with 1,25(OH)2D3. However, these protective effects of 1,25(OH)2D3 were significantly decreased after the PI3K/Akt pathway was inhibited by the LY294002 treatment. In vivo, X-ray, MRI, and histological analyses showed that 1,25(OH)2D3 treatment relieved the degree of IVDD in Sprague-Dawley rat disc puncture models. In summary, 1,25(OH)2D3 efficiently attenuated oxidative stress-induced NPMSC apoptosis and mitochondrial dysfunction via PI3K/Akt pathway and is a promising candidate treatment for the repair of IVDD.

Comparison of Minimally Invasive Transforaminal and Anterolateral Lumbar Interbody Fusion for Treatment of Low-grade Lumbar Spondylolisthesis.

STUDY DESIGN: This was a retrospective cohort study. OBJECTIVE: The aim was to compare the clinical outcomes, radiographic parameters and perioperative complications of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and anterolateral lumbar interbody fusion (ALLIF) for the treatment of low-grade lumbar spondylolisthesis. SUMMARY OF BACKGROUND DATA: Both MIS-TLIF and ALLIF are minimally invasive surgical methods for the treatment of lumbar degenerative diseases. However, few studies have compared the results of MIS-TLIF and ALLIF for the treatment of low-grade lumbar spondylolisthesis. MATERIALS AND METHODS: A total of 112 patients with low-grade lumbar spondylolisthesis were divided as MIS-TLIF group (n=59, mean age 61.7 y) or ALLIF group (n=53, mean age 60.1 y) according to the treatment method. The operative time, intraoperative blood loss, and length of hospital stay were recorded. Besides, clinical outcomes were evaluated by visual analog scale and Oswestry disability index score. Radiographic parameters were assessed by disc height, lumbar lordosis, segmental lordosis, and fusion rate. RESULTS: ALLIF significantly reduced operative time, intraoperative blood loss, and length of hospital stay compared with MIS-TLIF. Moreover, ALLIF was superior to MIS-TLIF in the early postoperative relief of back pain and recovery of lumbar function. However, there were no significant differences in the clinical outcomes at final follow-up between the 2 groups. The amount of change between preoperative and postoperative disc height, lumbar lordosis and segmental lordosis in ALLIF group were significantly higher than those in MIS-TLIF group (P<0.05). However, there were no significant differences in fusion rate and incidence of complications between the 2 groups. CONCLUSIONS: This study indicated that the final follow-up clinical outcomes, complication rate of ALLIF were similar to MIS-TLIF for the treatment of low-grade lumbar spondylolisthesis. However, ALLIF showed advantages in less surgical trauma, faster recovery, early postoperative relief of back pain, and radiographic parameters improvement.

Research Status of the Safety and Efficacy of Mesenchymal Stem Cells in the Treatment of COVID-19-Related Pneumonia: A Systematic Review and Meta-Analysis.

Mesenchymal stem cell (MSC) therapy is considered one of the most promising treatments in the context of the coronavirus disease 2019 (COVID-19) pandemic. However, the safety and effectiveness of MSCs in the treatment of COVID-19-associated pneumonia patients need to be systematically reviewed and analyzed. Two independent researchers searched for relevant studies published between October 2019 and April 2021 in the PubMed, Embase, Cochrane Library, WAN FANG, and CNKI databases. All relevant randomized controlled trials, clinically controlled studies, retrospective studies, case reports, letters (with valid data), and case series were included in this meta-analysis. A fixed-effects model and 95% confidence interval (CI) were used to analyze the results. A total of 22 studies involving 371 patients were included in the present study. Allogeneic MSCs from umbilical cord, adipose tissue, menstrual blood, placental tissue, Wharton's jelly, or unreported sources were administered in 247 participants. Combined results revealed that MSC therapy significantly reduced the incidence of adverse events [AEs; odds ratio (OR) = 0.43, 95% CI = 0.22-0.84, P = 0.01] and mortality (OR = 0.17, 95% CI = 0.06-0.49, P < 0.01), and the difference compared with control group was statistically significant. No serious MSC treatment-related AEs were reported. Lung function, radiographic outcomes, and inflammation- and immunity-related biomarker levels all showed improving trends. Therefore, MSC therapy is an effective and safe method for the treatment of COVID-19-associated pneumonia and shows advantages in reducing AEs and mortality. However, a standard and effective MSC treatment program must be developed.

Perioperative Hidden Blood Loss in Elderly Cervical Spondylosis Patients With Anterior Cervical Discectomy Fusion and Influencing Factors.

INTRODUCTION: To analyze the perioperative hidden blood loss (HBL) and its influencing factors in elderly cervical spondylosis patients treated with anterior cervical discectomy fusion (ACDF). MATERIALS AND METHODS: From January 2017 to December 2018, 128 elderly cervical spondylosis patients (age > 65 y) treated with ACDF were selected. The patients' height, weight, duration of symptoms, previous medical history and other basic information were routinely recorded. The hemoglobin (Hb), hematocrit (Hct) and blood coagulation function preoperative and the next day postoperative were recorded. The operation time, surgical bleeding, ASA classification, fixation method, total drainage and the time for extraction of drainage tube were recorded. The total blood loss (TBL) was calculated according to the Gross's formula, and HBL was calculated based on TBL, total drainage and surgical bleeding. The statistical analysis of HBL was performed, and then influential factors were further analyzed by multivariate linear regression analysis and t test. RESULTS: The mean surgical bleeding was 102.70 ± 46.78 mL and HBL was 487.98 ± 255.96 mL. HBL accounted for 67.61 ± 5.20% of TBL. According to the multiple linear regression analysis, the gender (P = 0.047), operation time (P = 0.000), fixation method (P = 0.014) and international normalized ratio (INR) (P = 0.003) influenced the amount of HBL. Body mass index (BMI) (P = 0.624), hypertension (P = 0.977), diabetes (P = 0.528), blood type (P = 0.577), ASA classification (P = 0.711), duration of symptoms (P = 0.661), preoperative cobb angle (P = 0.152), number of surgical level (P = 0.709), intramedullary hyperintensity (P = 0.967), drainage time (P = 0.294), postoperative drainage volume (P = 0.599), prothrombin time (PT) (P = 0.674), activated partial thromboplastin time (APTT) (P = 0.544) and thrombin time (TT) (P = 0.680) had no correlation with the amount of HBL. CONCLUSIONS: There was obvious HBL during the perioperative period of ACDF in elderly cervical spondylosis patients. The male patients, longer operation time, fusion with titanium plate and cage and high INR were independent risk factors for HBL.

Urolithin a alleviates oxidative stress-induced senescence in nucleus pulposus-derived mesenchymal stem cells through SIRT1/PGC-1α pathway.

BACKGROUND: In degenerative intervertebral disc (IVD), an unfavorable IVD environment leads to increased senescence of nucleus pulposus (NP)-derived mesenchymal stem cells (NPMSCs) and the inability to complete the differentiation from NPMSCs to NP cells, leading to further aggravation of IVD degeneration (IDD). Urolithin A (UA) has been proven to have obvious effects in delaying cell senescence and resisting oxidative stress. AIM: To explore whether UA can alleviate NPMSCs senescence and to elucidate the underlying mechanism. METHODS: In vitro, we harvested NPMSCs from rat tails, and divided NPMSCs into four groups: the control group, H2O2 group, H2O2 + UA group, and H2O2 + UA + SR-18292 group. Senescence-associated ß-Galactosidase (SA-ß-Gal) activity, cell cycle, cell proliferation ability, and the expression of senescence-related and silent information regulator of transcription 1/PPAR gamma coactivator-1α (SIRT1/ PGC-1α) pathway-related proteins and mRNA were used to evaluate the protective effects of UA. In vivo, an animal model of IDD was constructed, and X-rays, magnetic resonance imaging, and histological analysis were used to assess whether UA could alleviate IDD in vivo. RESULTS: We found that H2O2 can cause NPMSCs senescence changes, such as cell cycle arrest, reduced cell proliferation ability, increased SA-ß-Gal activity, and increased expression of senescence-related proteins and mRNA. After UA pretreatment, the abovementioned senescence indicators were significantly alleviated. To further demonstrate the mechanism of UA, we evaluated the mitochondrial membrane potential and the SIRT1/PGC-1α pathway that regulates mitochondrial function. UA protected mitochondrial function and delayed NPMSCs senescence by activating the SIRT1/PGC-1α pathway. In vivo, we found that UA treatment alleviated an animal model of IDD by assessing the disc height index, Pfirrmann grade and the histological score. CONCLUSION: In summary, UA could activate the SIRT1/PGC-1α signaling pathway to protect mitochondrial function and alleviate cell senescence and IDD in vivo and vitro.