Proinflammatory phenotype of B10 and B10pro cells elicited by TNF-α in rheumatoid arthritis.

OBJECTIVES: B10 and B10pro cells suppress immune responses via secreting interleukin (IL)-10. However, their regulators and underlying mechanisms, especially in human autoimmune diseases, are elusive. This study aimed to address these questions in rheumatoid arthritis (RA), one of the most common highly disabling autoimmune diseases. METHODS: The frequencies and functions of B10 and B10pro cells in healthy individuals and patients with RA were first analysed. The effects of proinflammatory cytokines, particularly tumour necrosis factor (TNF)-α on the quantity, stability and pathogenic phenotype of these cells, were then assessed in patients with RA before and after anti-TNF therapy. The underlying mechanisms were further investigated by scRNA-seq database reanalysis, transcriptome sequencing, TNF-α-/- and B cell-specific SHIP-1-/- mouse disease model studies. RESULTS: TNF-α was a key determinant for B10 cells. TNF-α elicited the proinflammatory feature of B10 and B10pro cells by downregulating IL-10, and upregulating interferon-γ and IL-17A. In patients with RA, B10 and B10pro cells were impaired with exacerbated proinflammatory phenotype, while anti-TNF therapy potently restored their frequencies and immunosuppressive functions, consistent with the increased B10 cells in TNF-α-/- mice. Mechanistically, TNF-α diminished B10 and B10pro cells by inhibiting their glycolysis and proliferation. TNF-α also regulated the phosphatidylinositol phosphate signalling of B10 and B10pro cells and dampened the expression of SHIP-1, a dominant phosphatidylinositol phosphatase regulator of these cells. CONCLUSIONS: TNF-α provoked the proinflammatory phenotype of B10 and B10pro cells by disturbing SHIP-1 in RA, contributing to the disease development. Reinstating the immunosuppressive property of B10 and B10pro cells might represent novel therapeutic approaches for RA.

Combination of scavenger receptor-A with anti-cyclic citrullinated peptide antibody for the diagnosis of rheumatoid arthritis.

OBJECTIVES: The routine biomarkers for rheumatoid arthritis (RA), including anticyclic citrullinated peptide antibody (anti-CCP), rheumatoid factor (RF), immunoglobulin M (IgM), erythrocyte sedimentation rate (ESR), and C-reaction protein (CRP) have limited sensitivity and specificity. Scavenger receptor-A (SR-A) is a novel RA biomarker identified by our group recently, especially for seronegative RA. Here, we performed a large-scale multicentre study to further assess the diagnostic value of SR-A in combination with other biomarkers for RA. METHODS: The performance of SR-A in combination with other biomarkers for RA diagnosis was first revealed by a pilot study, and was further elucidated by a large-scale multicentre study. A total of 1129 individuals from 3 cohorts were recruited in the study, including RA patients, healthy controls, and patients with other common rheumatic diseases. Diagnostic properties were evaluated by the covariate-adjusted receiver-operating characteristic (AROC) curve, sensitivity, specificity and clinical association, respectively. RESULTS: Large-scale multicentre analysis showed that SR-A and anti-CCP dual combination was the optimal method for RA diagnosis, increasing the sensitivity of anti-CCP by 13% (87% vs 74%) while maintaining a specificity of 90%. In early RA patients, SR-A and anti-CCP dual combination also showed promising diagnostic value, increasing the sensitivity of anti-CCP by 7% (79% vs 72%) while maintaining a specificity of 94%. Moreover, SR-A and anti-CCP dual combination was correlated with ESR, IgM, and autoantibodies of RA patients, further revealing its clinical significance. CONCLUSION: SR-A and anti-CCP dual combination could potentially improve early diagnosis of RA, thus improving the prognosis and reducing mortality.

SR-A neutralizing antibody: potential drug candidate for ameliorating osteoclastogenesis in rheumatoid arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by proliferative synovitis with deterioration of cartilage and bone. Osteoclasts (OCs) are the active participants in the bone destruction of RA. Although with great advances, most current therapeutic strategies for RA have limited effects on bone destruction. Macrophage scavenger receptor A (SR-A) is a class of pattern recognition receptors (PRRs) involved in bone metabolism and OC differentiation. More recently, our study revealed the critical role of SR-A in RA diagnosis and pathogenesis. Here, we further demonstrated that serum SR-A levels were positively correlated with bone destruction in patients with RA. Anti-SR-A neutralizing antibodies significantly inhibited OC differentiation and bone absorption in vitro in patients with RA, but not in healthy individuals, dampening the expression of OC-specific genes such as tartrate-resistant acid phosphatase (TRAP), cathepsin K (CTSK), and matrix metalloproteinase-9 (MMP-9). Similar results were also seen in collagen-induced arthritis (CIA) mice in vitro. Moreover, the anti-SR-A neutralizing antibody could further ameliorate osteoclastogenesis in vivo and ex vivo in CIA mice, accompanied by decreased serum levels of C-terminal telopeptide and IL-6, exhibiting potential protective effects. These results suggest that blockade of SR-A using anti-SR-A neutralizing antibodies might provide a promising therapeutic strategy for bone destruction in the RA.

Enzyme-activatable charge transfer in gold nanoclusters.

Surface-protecting ligands, as a major component of metal nanoclusters (MNCs), can dominate molecular characteristics, performance behaviors, and biological properties of MNCs, which brings diversity and flexibility to the nanoclusters and largely promotes their applications in optics, electricity, magnetism, catalysis, biology, and other fields. We report herein the design of a new kind of water-soluble luminescent gold nanoclusters (AuNCs) for enzyme-activatable charge transfer (CT) based on the ligand engineering of AuNCs with 6-mercaptopurine ribonucleoside (MPR). This elaborately designed cluster, Au5(MPR)2, can form a stable intramolecular CT state after light excitation, and exhibits long-lived color-tunable phosphorescence. After the cleavage by purine nucleoside phosphorylase (PNP), the CT triplet state can be easily directed to a low-lying energy level, leading to a bathochromic shift of the emission band accompanied by weaker and shorter-lived luminescence. Remarkably, these ligand-engineered AuNCs show high affinity towards PNP as well as decent performance for analyzing and visualizing enzyme activity and related drugs. The work of this paper provides a good example for diversifying physicochemical properties and application scenarios of MNCs by rational ligand engineering, which will facilitate future interest and new strategies to precisely engineer solution-based nanocluster materials.

Spinal Interferon Regulatory Factor 8 and Brain-derived Neurotrophic Factor in the Prefrontal Cortex are Involved in Pain-induced Depression Relief via Ultrasound-guided Pulsed Radiofrequency in a Rat Spared Nerve Injury Model.

BACKGROUND: Pain-depression comorbidity has become a great burden to individuals and society. Nevertheless, the mechanisms underlying comorbid diseases have still not been fully revealed. Ultrasound-guided pulsed radiofrequency (PRF) on peripheral nerves, which produces remarkable analgesia via high-frequency electromagnetic energy, has become a main, minimally invasive treatment for chronic neuropathic pain. OBJECTIVES: The aim of this study was to explore the effect of ultrasound-guided PRF on the sciatic nerve of spared nerve injury (SNI) rats to relieve pain-induced depression. STUDY DESIGN: Experimental trial in rats. SETTING: The research took place in the Laboratory of The First Affiliated Hospital of Wenzhou Medical University. METHODS: Sixty male Wistar rats were randomly divided into a sham group, an SNI group, an SNI + free-PRF group, and an SNI + PRF group. Ultrasound-guided PRF was applied to the sciatic nerve on day 7 after SNI. The basal paw mechanical withdrawal threshold (PMWT) was evaluated as a measure for pain-related behavior, and a  sucrose preference test was performed as a measure for depression-related behavior. The expression levels of spinal interferon regulatory factor 8 (IRF8) and of brain-derived neurotrophic factor (BDNF) in the prefrontal cortex (PFC) were also studied on days 21 and 42. RESULTS: The results showed that the PMWT was significantly decreased in rats following SNI operation; the decreased levels of PMWT were reversed in the SNI + PRF group after the application of PRF on the sciatic nerve on day 7. There were no statistically significant differences among the groups in the sucrose preference rate on day 21 after SNI operation. The sucrose preference rate on day 42 was higher in the SNI + PRF group than in the SNI + free-PRF group. Western blot and reverse transcription polymerase chain reaction also demonstrated that ultrasound-guided PRF on the sciatic nerve downregulated overexpression of spinal IRF8 and increased the levels of BDNF in the PFC. LIMITATIONS: This study was performed using only an SNI rat model which cannot represent all rodent neuropathic pain models. Only the short-term effectiveness of ultrasound-guided PRF on the sciatic nerve of SNI rats was investigated. The BDNF changes of other important brain areas were not taken into consideration in this study. CONCLUSIONS: These findings suggest that ultrasound-guided PRF on sciatic nerve could alleviate pain-induced depression. The mechanisms of this treatment may be involved in the downregulated spinal IRF8 and the increased BDNF in PFC.

Soluble CD24 is an inflammatory biomarker in early and seronegative rheumatoid arthritis.

Introduction: Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease characterized by autoantibody production, joint inflammation and bone destruction. Nearly 1/3 of RA patients with the active disease also exhibit a normal range of ESR and CRP. Here we assessed the performance and clinical significance of soluble CD24 (sCD24) as a biomarker of disease activity in RA.Methods: A total of 269 RA patients, 59 primary Sjogren's syndrome (SS) patients, 81 systematic lupus erythematosus (SLE) patients, 76 osteoarthritis (OA) patients and 97 healthy individuals (HC) were included in this study. Soluble CD24 in sera were detected by ELISA. Therefore, the concentration of sCD24 was analyzed in RA patients with different disease activity statuses.Results: The sCD24 was significantly increased in RA (2970 pg/mL), compared to other rheumatic diseases (380-520 pg/mL) and healthy individuals (320 pg/mL). Moreover, sCD24 was elevated in 66.67% of early RA and 61.11% of seronegative RA patients. In addition, sCD24 was significantly correlated with the disease duration and inflammatory indicators.Conclusion: The sCD24 could be an inflammatory biomarker in RA patients, especially in early and seronegative patients.

B cell subsets in adult-onset Still's disease: potential candidates for disease pathogenesis and immunophenotyping.

BACKGROUND: Adult-onset Still's disease (AOSD) is a systemic autoinflammatory disorder of unknown etiology. B cells are critical participants in different rheumatic diseases, and their roles in AOSD are rarely investigated. This study aimed to unveil the B cell subset features in AOSD and provide evidence for B cell-based diagnosis and targeted therapies of AOSD. METHODS: B cell subsets in the peripheral blood of AOSD patients and healthy controls (HCs) were detected by flow cytometry. Firstly, the frequencies of B cell subsets were compared. Then, the correlation analysis was performed to explore the correlation between B cell subsets and clinical manifestations in AOSD. Finally, unbiased hierarchical clustering was performed to divide AOSD patients into three groups with different B cell subset features, and the clinical characteristics of the three groups were compared. RESULTS: The frequencies of B cell subsets were altered in AOSD patients. Disease-promoting subsets (such as naïve B cells, double negative B cells (DN B cells), and plasmablasts) increased, and potential regulatory subsets (such as unswitched memory B cells (UM B cells) and CD24hiCD27+ B cells (B10 cells)) decreased in the peripheral blood of AOSD patients. In addition, the altered B cell subsets in AOSD correlated with the clinical and immunological features, such as immune cells, coagulation features, and liver enzymes. Intriguingly, AOSD patients could be divided into three groups with distinct B cell immunophenotyping: group 1 (naïve B cells-dominant), group 2 (CD27+ memory B cells-dominant), and group 3 (precursors of autoantibody-producing plasma cells-dominant). Moreover, these three group patients demonstrated differential manifestations, including immune cells, liver or myocardial enzymes, coagulation features, and systemic score. CONCLUSIONS: B cell subsets are significantly altered in AOSD patients, potentially contributing to the disease pathogenesis. These findings would inspire B cell-based diagnosis and targeted therapies for this refractory disease.

Highly Efficient Luminescence from Charge-Transfer Gold Nanoclusters Enabled by Lewis Acid.

Understanding the complicated intramolecular charge transfer (ICT) behaviors of nanomaterials is crucial to the development of high-quality nanoluminophores for various applications. However, the ICT process in molecule-like metal nanoclusters has been rarely explored. Herein, a proton binding-induced enhanced ICT state is discovered in 6-aza-2-thiothymine-protected gold nanoclusters (ATT-AuNCs). Such an excited-state electron transfer process gives rise to the weakened and red-shifted photoluminescence of these nanoclusters. By the joint use of this newfound ICT mechanism and a restriction of intramolecular motion (RIM) strategy, a red shift in the emission maxima of 30 nm with 27.5-fold higher fluorescence quantum efficiency is achieved after introducing rare-earth scandium ion (Sc3+) into ATT-AuNCs. Furthermore, it is found that upon the addition of Sc3+, the photoinduced electron transfer (PET) rate from ATT-AuNCs to minocycline is largely accelerated by forming a donor-bridge-acceptor structure. This paper offers a simple method to modulate the luminescent properties of metal nanoclusters for the rational design of next-generation sensing platforms.

Bis-Schiff base linkage-triggered highly bright luminescence of gold nanoclusters in aqueous solution at the single-cluster level.

Metal nanoclusters (NCs) have been developed as a new class of luminescent nanomaterials with potential applications in various fields. However, for most of the metal NCs reported so far, the relatively low photoluminescence quantum yield (QY) in aqueous solution hinders their applications. Here, we describe the utilization of bis-Schiff base linkages to restrict intramolecular motion of surface motifs at the single-cluster level. Based on Au22(SG)18 (SG: glutathione) NCs, an intracluster cross-linking system was constructed with 2,6-pyridinedicarboxaldehyde (PDA), and water-soluble gold NCs with luminescence QY up to 48% were obtained. The proposed approach for achieving high emission efficiency can be extended to other luminescent gold NCs with core-shell structure. Our results also show that the content of surface-bound Au(I)-SG complexes has a significant impact on the PDA-induced luminescence enhancement, and a high ratio of Au(I)-SG will be beneficial to increasing the photoluminescence intensity of gold NCs.

Structural resolution of disaccharides through halogen anion complexation using negative trapped ion mobility spectrometry.

Carbohydrates are an indispensable part of early life evolution. The determination of their structures is a key step to analyze their critical roles in biological systems. A variation of composition, glycosidic linkage, and (or) configuration between carbohydrate isomers induces structure diversity and brings challenges for their structural determination. Ion mobility spectrometry (IMS), an emerging gas-phase ion separation technology, has been considered as a promising tool for performing carbohydrate structure elucidation. In this work, eight disaccharides were analyzed by trapped ion mobility spectrometry-mass spectrometry (TIMS-MS) in the negative ion mode as the complexed form of [M + X]-, where M = disaccharide, and X = Cl, Br, and I. As compared to the positive ion analysis of the selected disaccharide in a sodiated form, a reversal charge state provided the ability to eliminate or even reverse the collision cross section (CCS) difference between disaccharide isomers. By the combination of TIMS analysis and the calculation of density functional theory, the only observed two conformers of ions [lactulose + I]- may result from different adduction sites for an iodide anion. Based on the comparison of different halogen adducts, the [M + I]- ion form exhibited more powerful ability for isomeric disaccharide differentiation with an average resolution (RP-P) of 1.17, which results in a 34.5% improvement as compared to the corresponding chloride adducts. This result indicates that the use of negative charge states, especially the complexation of an iodide anion, could be a supplemental strategy to commonly used positive ion analysis for carbohydrate separation.

Profiling and fingerprinting strategies to assess exposure of edible plants to herbicides.

Raphanus sativus var. longipinnatus, was exposed under experimental conditions to herbicides: rimsulfuron (RIM), administrated as (1) pure substance, (2) in commercially available formulation (RIMEL), (3) its degradation product: 4,6-dimethoxypyrimidin-2-amine (2ADP), (4) mesotrione (MES), (5) sulcotrione (SUL). Profiling and fingerprinting strategies, conducted by LC-MS/MS-FL, were employed to find markers of plant exposure to herbicide stress. The presence ofRIM metabolite in the tissues of plant exposed to this herbicide proved that it is necessary to determine both parent compound and its by-products to obtain reliable information on plant exposure to agrochemicals. A higher content of normetanephrine (NMN) (18-175%) and lower content of tyramine (TYR) (49-75%) and epinephrine (E) (75-83%) was observed in plant tissues exposed to RIM and 2ADP in comparison to blank sample. Therefore, NMN, TRY and E may be considered as markers of plant response to RIM. Non-target analysis enables to recognize the type of herbicide used during cultivation.

Casein Kinase II exacerbates rheumatoid arthritis via promoting Th1 and Th17 cell inflammatory responses.

OBJECTIVES: Studies have demonstrated that CK2 is engaged in CD4+ T cell proliferation and activation. We investigated the potential involvement of CK2 in the pathogenesis of rheumatoid arthritis (RA). METHODS: Peripheral blood and synovial fluid mononuclear cells (PBMC and SFMC) of RA patients, as well as splenocytes of collagen-induced arthritis (CIA) mice were treated with different doses of CK2 inhibitor CX4945 in vitro. Then, the Th1, Th2, Th17, and Treg cell responses were analyzed. In addition, CIA mice were administrated with CX4945 via oral gavage. Accordingly, the arthritis scores, bone destruction, tissue damage, and the CD4+ T cell subsets were assessed. RESULTS: The expression of CK2 was upregulated in CD4+ T cells under RA circumstance. In vitro CX4945 treatment significantly inhibited the Th1 and Th17 cell responses, while promoted the Th2 cell responses in RA patient PBMC, SFMC and CIA mouse splenocytes, dampening IFN-γ and IL-17A production. Moreover, administration of CX4945 ameliorated the severity of arthritis in CIA mice, along with decreased Th1 and Th17 cells. However, CX4945 seemed to have minimal effect on RA Treg cells. CONCLUSION: CK2 serves as an important regulator of the Th1 and Th17 cell axes in RA, thus contributing to the disease aggravation.

The clinical effectiveness and safety of alprostadil combined with alpha lipoic acid in the treatment of diabetic peripheral neuropathy: A protocol for systematic review and meta-analysis.

BACKGROUND: The pathogenesis of diabetic peripheral neuropathy is more complex and it is not yet clear, but studies have shown that microangiopathy and oxidative stress responses are closely related to their pathogenesis. At present, the treatment of improving microcirculation and antioxidant stress is mainly used in clinical. Alprostadil is a commonly used vasodilator, and alpha lipoic acid is an antioxidant, which can effectively reduce oxidative stress responses and delay the progression of diabetes mellitus and its complications. However, there is a lack of evidence-based medical evidence for alprostadil combined with alpha lipoic acid in the treatment of diabetic peripheral neuropathy, and this article aims to understand the clinical effectiveness and safety of alprostadil combined with alpha lipoic acid in the treatment of diabetic peripheral neuropath by a meta-analysis of published randomized controlled trials. METHODS: In this study, we obtain the relevant literature by retrieving 8 electronic databases, including PubMed, EMBASE, Web of Science, the Cochrane Library, CBM, CNKI, VIP, and WanFang Database. Retrieving a randomized controlled study of alprostadil combined with alpha lipoic acid in the treatment of diabetic peripheral neuropath, while the language of the literature is restricted and it only includes Chinese and English literature. For the publication of literature, the time is from the beginning of the database to August 31, 2020. In the English database, using the retrieval method of subject word combined free word. The two researchers read the titles and abstracts of all the literature independently based on the inclusion and exclusion criteria. If it cannot be determined whether the literature is included by reading the title and abstract, then download and read the full text of the literature. If there is a dispute between the two researchers about the literature, so it should discuss the dispute with the third researcher in order to reach a conclusion. Using the bias risk assessment tool of randomized controlled trials in Cochrane systematic review to evaluate the bias risk of the included literature; Using RevMan 5.3 software to conduct statistical analysis; Using funnel plot analysis to analyze the situation of literature publication bias. RESULTS: This study will provide a high-quality evidence on the effects of hydrolyzed protein formula milk on gastrointestinal diseases and physical development of premature infants. CONCLUSION: This study will draw reliable evidence-based medical evidence for alprostadil combined with Alpha lipoic acid in the treatment of diabetic peripheral neuropathy, thus providing help for the clinical treatment of diabetic peripheral neuropathy. REGISTRATION NUMBER: Open Science Framework (OSF), registration number: DOI 10.17605/OSF.IO/7S46G.

Scavenger receptor-A is a biomarker and effector of rheumatoid arthritis: A large-scale multicenter study.

Early diagnosis is critical to improve outcomes in rheumatoid arthritis (RA), but current diagnostic tools have limited sensitivity. Here we report a large-scale multicenter study involving training and validation cohorts of 3,262 participants. We show that serum levels of soluble scavenger receptor-A (sSR-A) are increased in patients with RA and correlate positively with clinical and immunological features of the disease. This discriminatory capacity of sSR-A is clinically valuable and complements the diagnosis for early stage and seronegative RA. sSR-A also has 15.97% prevalence in undifferentiated arthritis patients. Furthermore, administration of SR-A accelerates the onset of experimental arthritis in mice, whereas inhibition of SR-A ameliorates the disease pathogenesis. Together, these data identify sSR-A as a potential biomarker in diagnosis of RA, and targeting SR-A might be a therapeutic strategy.

Downregulated spinal IRF8 and BDNF in NAC are involved in neuropathic pain-induced depression relief via pulsed radiofrequency on dorsal root ganglion in rat SNI model.

Pulsed radiofrequency (PRF) on the dorsal root ganglion (DRG), which produces remarkable analgesia through high-frequency electromagnetic energy, has become a main therapy for chronic neuropathic pain. The chronic neuropathic pain in patients is frequently accompanied by depression. However, the underlying neurophysiological mechanisms of the treatment of PRF on DRG for the neuropathic pain-induced depression remain unclear. This study was designed to explore the effect of PRF on DRG on the neuropathic pain-induced depression in rats with spared nerve injury (SNI). Here, we found that PRF on DRG or intrathecal injection of the interferon regulatory factor 8 (IRF8) siRNA prevented the increase of mechanical allodynia and depression-like behaviors of rats after receiving SNI. Meanwhile, Western blot, immunohistochemistry, and RT-PCR revealed that PRF on DRG or intrathecal injection of IRF8 siRNA inhibited IRF8 overexpression in the spinal cord and brain-derived neurotrophic factor (BDNF) in NAc. These results suggest that neuropathic pain-induced depression could be attenuated by PRF applied to DRG in SNI rats. The suppressed overexpression of the spinal IRF8 and BDNF in NAc may play an important role and contribute considerably to effectiveness of the therapy by PRF on DRG.

Regulation of metal ion selectivity of fluorescent gold nanoclusters by metallophilic interactions.

Although numerous sensors have been successfully fabricated for the detection of various heavy metal ions by employing fluorescent gold nanoclusters (AuNCs) as nanoprobes, serious cross-interference often occurs when these ions coexist in samples, which results in glaring errors in quantification. In this study, glutathione-protected AuNCs (GSH-AuNCs) were synthesized and found to respond to both Cu2+ and Hg2+ via fluorescence suppression. Intriguingly, addition of Ag+ to GSH-AuNCs could completely inhibit the quenching effect of Hg2+ while not affecting the Cu2+-mediated quenching process. Ag+ can combine with Au+ on the surface of AuNCs to form a strong Ag+-Au+ metallic bond, which disrupts the interaction between Hg2+ and Au+ and thus eliminates the corresponding quenching effect. Based on this phenomenon, a simple sensing approach for highly selective and sensitive detection of Cu2+ in aqueous solution was developed using the GSH-AuNC/Ag+ complex as a fluorescent turn-off nanoprobe. The proposed method exhibited good linearity in the concentration range 0.02-10 µM with a limit of detection of 12 nM. This assay was demonstrated to be suitable for determination of Cu2+ in real water samples even in the presence of Hg2+, showing great promise as a tool for assessment of environmental security and drinking water quality.

Pulsed Radiofrequency on Dorsal Root Ganglion Relieved Neuropathic Pain Associated with Downregulation of the Spinal Interferon Regulatory Factor 8, Microglia, p38MAPK Expression in a CCI Rat Model.

BACKGROUND: Interferon regulatory factor 8 (IRF8), which is induced by peripheral nerve injury (PNI), plays a key role in activating spinal microglia to release inflammatory cytokines in a p38-dependent way, thereafter results in formation of central sensitization. Pulsed radiofrequency (PRF) on dorsal root ganglion (DRG) alleviates neuropathic pain and inhibits the microglial activation in chronic constriction injury (CCI) rats. However, the consequences of PRF on spinal IRF8 of CCI rats remains unknown. OBJECTIVE: We explore if PRF on DRG of rats with CCI could restrain IRF8, microglia, and p38 hyperactivity in the spinal cord to alleviate neuropathic pain. STUDY DESIGN: A randomized, controlled animal study. SETTING: Department of Pain Management, Fujian Provincial Hospital, Fujian Key Laboratory of Geriatrics, Provincial Clinic College of Fujian Medical University. METHODS: The changes in pain behaviors and the expressions of IRF8, Iba1 and p-p38 in the spinal cord of CCI rats which were administrated with antisense/ mismatch oligodeoxynucleotide of IRF8 were studied. Rats in CCI+AS ODN group, CCI+MM ODN group or CCI+NS group were intrathecally treated with antisense oligodeoxynucleotide of IRF8, mismatch oligodeoxynucleotide of IRF8 or same volume 0.9% NaCl once daily respectively, beginning from the day after nerve transection 12 hours and lasting for 7 days. The effects of PRF on L4-5 DRG of rats with CCI were investigated. PRF was applied adjacent to the L4-5 DRG at an intensity of 45 V for 6 minutes after CCI, whereas the control rats were treated without radiofrequency current. The withdrawal thresholds were studied and the spinal levels of IRF8, ionized calcium-binding adapter molecule 1 (Iba1, microglia characteristic marker) and p-p38 were calculated by ELISA, western blot, RT-PCR, and immunofluorescence. RESULTS: Intrathecal administration of antisense oligodeoxynucleotide of IRF8 led to the reversal of CCI-induced allodynia, lower activation of spinal microglia and p-p38. Withdrawal thresholds were partially recovered after a single PRF treatment for 14 days. CCI-induced IRF8 upregulation, microglia hyperactivity, and p38 phosphorylation in the spinal cord were reduced due to PRF treatment. However, PRF did not alter pain behaviors and pain signals in normal rats. LIMITATIONS: In our study, one time point was selected just to assess the levels of microglia, and p-p38. The changes of IRF8, microglia, p-p38 in the ipsilateral DRG were not investigated. A more detailed study on how PRF on the DRG could further relieve NP is needed. CONCLUSIONS: Restraining IRF8, microglia and p38 hyperactivity in the spinal cord of CCI rats involved in the contribution to the long-lasting analgesia of PRF. KEY WORDS: Neuropathic pain, pulsed radiofrequency, dorsal root ganglion, microglia, p38MAPK, Interferon regulatory factor 8, chronic constriction injury of sciatic nerve.

The effects of lidocaine used in sciatic nerve on the pharmacodynamics and pharmacokinetics of ropivacaine in sciatic nerve combined with lumbar plexus blockade: a double-blind, randomized study.

In this controlled, randomized, double-blind study, we compared the pharmacodynamics and pharmacokinetics of ropivacaine and staged injection of lidocaine and ropivacaine in a combined lumbar plexus-sciatic nerve block. The experiment was performed in two parts: pharmacodynamics study (Group r, n = 20; Group lr, n = 20) and pharmacokinetics study (Group R, n = 10; Group LR, n = 10). The sciatic nerve blockade was performed using either (1) 10 mL of 2% lidocaine and then 10 mL of 0.75% ropivacaine (Group lr and Group LR) or (2) 10 mL of normal saline (N.S.) and then 10 mL of 0.75% ropivacaine (Group r and Group R). Two kinds of solutions were 'staged' injection. The sensory onset time and sensory recovery time were assessed in the pharmacodynamics study. Arterial blood samples were collected for the pharmacokinetics study. Sciatic sensory block onset times were reduced, and the sensory recovery times were decreased in Group lr. C(max) of ropivacaine in Group LR was significantly higher than that in Group R. A significant increase in AUC((0-t)) and AUC((0-∞)) was observed in Group LR compared with Group R. When 2% lidocaine and 0.75% ropivacaine are used for a combined sciatic nerve-lumbar plexus block by 'staged' injection, lidocaine induced faster onset times, decreased the block duration and increased the AUC and C(max) of ropivacaine.