Branched-Chain Amino Acids Deficiency Promotes Diabetic Neuropathic Pain Through Upregulating LAT1 and Inhibiting Kv1.2 Channel.

Diabetic neuropathic pain (DNP), one of the most common complications of diabetes, is characterized by bilateral symmetrical distal limb pain and substantial morbidity. To compare the differences  is aimed at serum metabolite levels between 81 DNP and 73 T2DM patients without neuropathy and found that the levels of branched-chain amino acids (BCAA) are significantly lower in DNP patients than in T2DM patients. In high-fat diet/low-dose streptozotocin (HFD/STZ)-induced T2DM and leptin receptor-deficient diabetic (db/db) mouse models, it is verified that BCAA deficiency aggravated, whereas BCAA supplementation alleviated DNP symptoms. Mechanistically, using a combination of RNA sequencing of mouse dorsal root ganglion (DRG) tissues and label-free quantitative proteomic analysis of cultured cells, it is found that BCAA deficiency activated the expression of L-type amino acid transporter 1 (LAT1) through ATF4, which is reversed by BCAA supplementation. Abnormally upregulated LAT1 reduced Kv1.2 localization to the cell membrane, and inhibited Kv1.2 channels, thereby increasing neuronal excitability and causing neuropathy. Furthermore, intraperitoneal injection of the LAT1 inhibitor, BCH, alleviated DNP symptoms in mice, confirming that BCAA-deficiency-induced LAT1 activation contributes to the onset of DNP. These findings provide fresh insights into the metabolic differences between DNP and T2DM, and the development of approaches for the management of DNP.

Current Status of Cognition and Clinical Practice of Refractory Cancer Pain in Shanghai: A Questionnaire Survey.

Purpose: This study aimed to assess the current status of clinical practice of refractory cancer pain (RCP) among a sample of physicians specializing in cancer pain management in Shanghai. Methods: From 2019 to 2021, a questionnaire survey was conducted among physicians engaged in diagnosis and treatment of cancer pain through the questionnaire WJX network platform in Shanghai, China. Results: A total of 238 responses participated in the survey. This survey reports physicians' understanding and incidence rate of breakthrough cancer pain (BTCP). The choice of analgesics and satisfaction of analgesic effect were investigated. We also investigated doctors' knowledge of the diagnostic criteria for RCP and their tendency to choose analgesics. Oral immediate-release morphine and intravenous or subcutaneous morphine injection have been the common treatment approach for transient cancer pain exacerbations. The main barriers to pain management are lack of standardized treatment methods for RCP, lack of knowledge related to RCP, and single drug dosage form. Doctors believe the most necessary measures to improve the current situation of poor cancer pain control include improving medical staff's understanding and treatment techniques for RCP, updating treatment techniques and methods, and improving the configuration of drug types in medical institutions. Clinicians expect to improve understanding and treatment techniques through systematic training. Conclusion: Despite multiple available analgesic measures, the treatment of RCP remains challenging. Improving the understanding of medical staff towards RCP, improving treatment techniques, and increasing the accessibility of multiple drug types are important ways to improve the satisfaction of cancer pain management in the future.

Formate Might Be a Novel Potential Serum Metabolic Biomarker for Type 2 Diabetic Peripheral Neuropathy.

Background: As one of the most frequent complications of type 2 diabetes mellitus (T2DM), diabetic peripheral neuropathy (DPN) shows a profound impact on 50% of patients with symptoms of neuropathic pain, numbness and other paresthesia. No valid serum biomarkers for the prediction of DPN have been identified in the clinic so far. This study is to investigate the potential serum biomarkers for DPN firstly based on 1H-Nuclear Magnetic Resonance (1H-NMR)-based metabolomics technique. Methods: Thirty-six patients enrolled in this study were divided into two groups: 18 T2DM patients without DPN (T2DM group) and 18 T2DM patients with DPN (DPN group). Serum metabolites were measured via 1H-NMR spectroscopy. Bioinformatic approaches including principal component analysis (PCA), orthogonal partial least squares-discriminant analysis (OPLS-DA), independent sample t-test, Fisher's test, Pearson and Spearman correlation analysis, Stepwise multiple linear regression analysis and receiver operating characteristic (ROC) curve analysis were used to identify the potential altered serum biomarkers. Results: A total of 20 metabolites were obtained and further analyzed. Formate was identified as the only potential biomarker that decreased in the DPN group with statistical significance after multiple comparisons (p<0.05). Formate also displayed a negative relationship with some elevated clinical markers in DPN. ROC curve analysis showed a good discriminative ability for formate in DPN with an area under the curve (AUC) value of 0.981. Conclusion: Formate could be considered a potential serum metabolic biomarker for DPN. The reduced level of formate in DPN may be associated with mitochondrial dysfunction and gut microbiota alteration. Monitoring the level of serum formate would be an important strategy for the early diagnosis of DPN and a supplement of formate may be a promising treatment for DPN in the future.

BDNF-TrkB signaling pathway-mediated microglial activation induces neuronal KCC2 downregulation contributing to dynamic allodynia following spared nerve injury.

Mechanical allodynia can be evoked by punctate pressure contact with the skin (punctate mechanical allodynia) and dynamic contact stimulation induced by gentle touching of the skin (dynamic mechanical allodynia). Dynamic allodynia is insensitive to morphine treatment and is transmitted through the spinal dorsal horn by a specific neuronal pathway, which is different from that for punctate allodynia, leading to difficulties in clinical treatment. K+-Cl- cotransporter-2 (KCC2) is one of the major determinants of inhibitory efficiency, and the inhibitory system in the spinal cord is important in the regulation of neuropathic pain. The aim of the current study was to determine whether neuronal KCC2 is involved in the induction of dynamic allodynia and to identify underlying spinal mechanisms involved in this process. Dynamic and punctate allodynia were assessed using either von Frey filaments or a paint brush in a spared nerve injury (SNI) mouse model. Our study discovered that the downregulated neuronal membrane KCC2 (mKCC2) in the spinal dorsal horn of SNI mice is closely associated with SNI-induced dynamic allodynia, as the prevention of KCC2 downregulation significantly suppressed the induction of dynamic allodynia. The over activation of microglia in the spinal dorsal horn after SNI was at least one of the triggers in SNI-induced mKCC2 reduction and dynamic allodynia, as these effects were blocked by the inhibition of microglial activation. Finally, the BDNF-TrkB pathway mediated by activated microglial affected SNI-induced dynamic allodynia through neuronal KCC2 downregulation. Overall, our findings revealed that activation of microglia through the BDNF-TrkB pathway affected neuronal KCC2 downregulation, contributing to dynamic allodynia induction in an SNI mouse model.

DHX9/DNA-tandem repeat-dependent downregulation of ciRNA-Fmn1 in the dorsal horn is required for neuropathic pain.

Circular RNAs (ciRNAs) are emerging as new players in the regulation of gene expression. However, how ciRNAs are involved in neuropathic pain is poorly understood. Here, we identify the nervous-tissue-specific ciRNA-Fmn1 and report that changes in ciRNA-Fmn1 expression in spinal cord dorsal horn neurons play a key role in neuropathic pain after nerve injury. ciRNA-Fmn1 was significantly downregulated in ipsilateral dorsal horn neurons after peripheral nerve injury, at least in part because of a decrease in DNA helicase 9 (DHX9), which regulates production of ciRNA-Fmn1 by binding to DNA-tandem repeats. Blocking ciRNA-Fmn1 downregulation reversed nerve-injury-induced reductions in both the binding of ciRNA-Fmn1 to the ubiquitin ligase UBR5 and the level of ubiquitination of albumin (ALB), thereby abrogating the nerve-injury-induced increase of ALB expression in the dorsal horn and attenuating the associated pain hypersensitivities. Conversely, mimicking downregulation of ciRNA-Fmn1 in naïve mice reduced the UBR5-controlled ubiquitination of ALB, leading to increased expression of ALB in the dorsal horn and induction of neuropathic-pain-like behaviors in naïve mice. Thus, ciRNA-Fmn1 downregulation caused by changes in binding of DHX9 to DNA-tandem repeats contributes to the genesis of neuropathic pain by negatively modulating UBR5-controlled ALB expression in the dorsal horn.

Transcription factor ETS proto-oncogene 1 contributes to neuropathic pain by regulating histone deacetylase 1 in primary afferent neurons.

Nerve injury can induce aberrant changes in ion channels, enzymes, and cytokines/chemokines in the dorsal root ganglia (DRGs); these changes are due to or at least partly governed by transcription factors that contribute to the genesis of neuropathic pain. However, the involvement of transcription factors in neuropathic pain is poorly understood. In this study, we report that transcription factor (TF) ETS proto-oncogene 1 (ETS1) is required for the initiation and development of neuropathic pain. Sciatic nerve chronic constrictive injury (CCI, a clinical neuropathic pain model) increases ETS1 expression in the injured male mouse DRG. Blocking this upregulation alleviated CCI-induced mechanical allodynia and thermal hyperalgesia, with no apparent effect on locomotor function. Mimicking this upregulation results in the genesis of nociception hypersensitivity; mechanistically, nerve injury-induced ETS1 upregulation promotes the expression of histone deacetylase 1 (HDAC1, a key initiator of pain) via enhancing its binding activity to the HDAC1 promotor, leading to the elevation of spinal central sensitization, as evidenced by increased expression of p-ERK1/2 and GFAP in the dorsal spinal horn. It appears that the ETS1/HDAC1 axis in DRG may have a critical role in the development and maintenance of neuropathic pain, and ETS1 is a potential therapeutic target in neuropathic pain.

Mesenchymal stem cell-derived exosome mediated long non-coding RNA KLF3-AS1 represses autophagy and apoptosis of chondrocytes in osteoarthritis.

Osteoarthritis is a degenerative joint disease and a leading cause of adult disability. Our previous study has reported that mesenchymal stem cell-derived exosomes (MSC-Exo) mediated long non-coding RNA KLF3-AS1 improves osteoarthritis. This study aims to investigate the molecular mechanism of KLF3-AS1 in osteoarthritis. Chondrocytes were treated with IL-1ß to induce chondrocyte injury, followed by MSC-Exo treatment. We found that MSC-Exo enhanced KLF3-AS1 expression in IL-1ß-treated chondrocytes. IL-1ß treatment reduced cell viability and enhanced apoptosis in chondrocytes. MSC-Exo-mediated KLF3-AS1 promoted cell viability and repressed apoptosis of IL-1ß-treated chondrocytes. Rapamycin (autophagy activator) promoted cell viability and suppressed apoptosis of chondrocytes by activating autophagy. Moreover, KLF3-AS1 interacted with YBX1 in chondrocytes. MSC-Exo-mediated KLF3-AS1 activated PI3K/Akt/mTOR signaling pathway, which was abrogated by YBX1 silencing. MSC-Exo-mediated KLF3-AS1 repressed autophagy and apoptosis of chondrocytes by activating PI3K/Akt/mTOR signaling pathway. In conclusion, our data demonstrate that MSC-Exo-mediated KLF3-AS1 inhibits autophagy and apoptosis of IL-1ß-treated chondrocyte through PI3K/Akt/mTOR signaling pathway. KLF3-AS1 activates PI3K/Akt/mTOR signaling pathway by targeting YBX1 to improve the progression of osteoarthritis. Thus, this work suggests that MSC-Exo-mediated KLF3-AS1 may be a potential therapeutic target for osteoarthritis.

Stable DNA Aptamer-Metal-Organic Framework as Horseradish Peroxidase Mimic for Ultra-Sensitive Detection of Carcinoembryonic Antigen in Serum.

Carcinoembryonic antigen (CEA) is an important broad-spectrum tumor marker. For CEA detection, a novel type of metal-organic framework (MOF) was prepared by grafting CEA aptamer-incorporated DNA tetrahedral (TDN) nanostructures into PCN-222 (Fe)-based MOF (referred as CEAapt-TDN-MOF colloid nanorods). The synthesized CEAapt-TDN-MOF is a very stable detection system due to the vertex phosphorylated TDN structure at the interface, possessing a one-year shelf-life. Moreover, it exhibits a significant horseradish peroxidase mimicking activity due to the iron porphyrin ring, which leads to a colorimetric reaction upon binding toward antibody-captured CEA. Using this method, we successfully achieved the highly specific and ultra-sensitive detection of CEA with a limit of detection as low as 3.3 pg/mL. In addition, this method can detect and analyze the target proteins in clinical serum samples, effectively identify the difference between normal individuals and patients with colon cancer, and provide a new method for the clinical diagnosis of tumors, demonstrating a great application potential.

Injectable PLGA-Coated Ropivacaine Produces A Long-Lasting Analgesic Effect on Incisional Pain and Neuropathic Pain.

The management of persistent postsurgical pain and neuropathic pain remains a challenge in the clinic. Local anesthetics have been widely used as simple and effective treatment for these 2 disorders, but the duration of their analgesic effect is short. We here reported a new poly lactic-co-glycolic acid (PLGA)-coated ropivacaine that was continuously released in vitro for at least 6 days. Perisciatic nerve injection of the PLGA-coated ropivacaine attenuated paw incision-induced mechanical allodynia and heat hyperalgesia during the incisional pain period, and spared nerve injury-induced mechanical and cold allodynia for at least 7 days postinjection. This effect was dose-dependent. Perisciatic nerve injection of the PLGA-coated ropivacaine did not produce detectable inflammation, tissue irritation, or damage in the sciatic nerve and surrounding muscles at the injected site, dorsal root ganglion, spinal cord, or brain cortex, although the scores for grasping reflex were mildly and transiently reduced in the higher dosage-treated groups. PERSPECTIVE: Given that PLGA is an FDA-approved medical material, and that ropivacaine is used currently in clinical practice, the injectable PLGA-coated ropivacaine represents a new and highly promising avenue in the management of postsurgical pain and neuropathic pain.

Silencing long non-coding RNA MEG3 accelerates tibia fraction healing by regulating the Wnt/ß-catenin signalling pathway.

As fracture healing is related to gene expression, fracture healing is prospected to be implicated in long non-coding RNAs (lncRNAs). This study focuses on the effects of epigenetic silencing of long non-coding RNA maternally expressed gene 3 (lncRNA MEG3) on fracture healing by regulating the Wnt/ß-catenin signalling pathway. Genes expressed in fracture were screened using bioinformatics and the subcellular location of MEG3 was determined using FISH. Next, we successfully established tibia fracture (TF) models of C57BL/6J and Col2a1-ICAT mice and the effect of silencing lncRNA MEG3 on fracture healing was detected after TF mice were treated with phosphate buffer saline (PBS), MEG3 siRNA and scramble siRNA. X-ray imaging, Safranin-O/fast green and haematoxylin-eosin (HE) staining and histomorphometrical and biomechanical analysis were adopted to observe and to detect the fracture healing conditions. Additionally, the positive expression of collagen II and osteocalcin was examined using immunohistochemistry. At last, in the in vitro experiment, the relationship of MEG3 and the Wnt/ß-catenin signalling pathway in fraction healing was investigated. MEG3 was located in the cell nucleus. In addition, it was found that MEG3 and the Wnt/ß-catenin signalling pathway were associated with fraction healing. Moreover, silencing MEG3 was proved to elevate callus area and maximum bending load and to furthermore enhance the recanalization of bone marrow cavity. Finally, MEG3 knockdown elevated levels of Col10a1, Runx2, Osterix, Osteocalcin, Wnt10b and ß-catenin/ß-catenin whereas it reduced p-GSK-3ß/GSK-3ß levels. Taken together, our data supported that epigenetic silencing of lncRNA MEG3 could promote the tibia fracture healing by activating the Wnt/ß-catenin signalling pathway.

Exosomal KLF3-AS1 from hMSCs promoted cartilage repair and chondrocyte proliferation in osteoarthritis.

The present study was designed to explore whether exosomal lncRNA-KLF3-AS1 derived from human mesenchymal stem cells (hMSCs) can serve as a positive treatment for osteoarthritis (OA). hMSCs and MSC-derived exosomes (MSC-exo) were prepared for morphological observation and identification by transmission electron microscopy and flow cytometry. IL-1ß-induced OA chondrocytes and collagenase-induced rat model of OA were established for the further experiments. Lentivirus-mediated siRNA targeting KLF3-AS1 was transfected into MSCs for silencing KLF3-AS1. The real-time quantitative PCR and western blotting analysis were performed to examine the mRNA and protein levels of type II collagen alpha 1 (Col2a1), aggrecan, matrix metalloproteinase 13 and runt-related transcription factor 2. Cell proliferation, apoptosis and migration were evaluated by CCK-8 assay, flow cytometry and transwell assay. HE (hematoxylin and eosin) staining and immunohistochemistry were used for histopathological studies. MSC-exo ameliorated IL-1ß-induced cartilage injury. Furthermore, lncRNA KLF3-AS1 was markedly enriched in MSC-exo, and exosomal KLF3-AS1 suppressed IL-1ß-induced apoptosis of chondrocytes. Further in vivo investigation indicated that exosomal KLF3-AS1 promoted cartilage repair in a rat model of OA. Exosomal KLF3-AS1 promoted cartilage repair and chondrocyte proliferation in a rat model of OA, which might be an underlying therapeutic target for OA.

MSC-derived exosomes promote proliferation and inhibit apoptosis of chondrocytes via lncRNA-KLF3-AS1/miR-206/GIT1 axis in osteoarthritis.

BACKGROUND: Exosomes secreted by human mesenchymal stem cells (hMSCs) have been shown to promote cartilage regeneration. This study aimed to explore whether exosomal lncRNA-KLF3-AS1 derived from hMSCs can promote chondrocyte proliferation via miR-206/GIT1 axis in osteoarthritis (OA). METHODS: hMSCs and MSC-derived exosomes (MSC-exo) were prepared for morphological observation and identification by transmission electron microscopy (TEM) and flow cytometry. IL-1ß-induced OA chondrocytes and collagenase-induced mouse OA model were established for the further experiments. Luciferase activity assay was performed to test whether miR-206 could bind to KLF3-AS1 or GIT1. Cell proliferation and apoptosis were evaluated by CCK-8 assay and flow cytometry, respectively. RESULTS: MSC-Exos increased chondrogenic genes Col2a1 (type II collagen alpha 1) and aggrecan, decreased hondrocyte hypertrophy markers MMP-13 (matrix metalloproteinase-13) and Runx2 (runt-related transcription factor 2) in chondrocytes isolated from OA model mice. Furthermore, MSC-Exos attenuated IL-1ß-induced chondrocyte proliferation inhibition and apoptosis induction. Moreover, MSCKLF3-AS1-Exos (exosomes derived from KLF3-AS1-overexpressing-MSCs) ameliorated IL-1ß-induced chondrocyte injury. Results also demonstrated that KLF3-AS1 acted as a competitive endogenous RNA (ceRNA) by sponging miR-206 to facilitate GIT1 expression. In addition, miR-206 overexpression and GIT1 knockdown reversed MSCKLF3-AS1-Exos-mediated attenuation of chondrocyte injury. CONCLUSION: Exosomal KLF3-AS1 derived from MSCs involved in MSC-Exos-mediated chondrocyte proliferation induction and chondrocyte apoptosis inhibition via miR-206/GIT1 axis. Abbreviation: G-protein-coupled receptor kinase interacting protein-1 (GIT1).

End-tidal carbon dioxide monitoring improves patient safety during propofol-based sedation for breast lumpectomy: A randomised controlled trial.

BACKGROUND: The use of sedation is becoming more commonplace. Although pulse oximetry is a standard monitoring procedure during sedation, it cannot accurately detect early hypoventilation. End-tidal carbon dioxide (EtCO2) monitoring can be an earlier indicator of airway compromise; however, the existing literature is limited to a few studies with varying outcomes. OBJECTIVES: To evaluate whether EtCO2 monitoring decreases the incidences of CO2 retention and apnoeic events in propofol-based sedation. DESIGN: Randomised controlled study. SETTING: A tertiary hospital. PATIENTS: Two hundred women (aged 18 to 65 years, ASA physical status 1 or 2) who were scheduled for breast lumpectomy between June 2017 and August 2017. INTERVENTIONS: Patients were allocated randomly to receive either standard monitoring or standard monitoring and EtCO2 monitoring. MAIN OUTCOME MEASURES: The primary outcome was the incidence of CO2 retention. The secondary outcomes were the number of actions taken to restore ventilation, variations in PaCO2 and pH, the frequency of apnoea and the recovery time. RESULTS: CO2 retention occurred significantly less often in the EtCO2 monitoring group (10 vs. 87%; P < 0.0001). In the standard monitoring group, the mean PaCO2 was more than 6 kPa (45 mmHg) and the pH was less than 7.35 at 5, 10, 20 and 30 min after induction of anaesthesia and at the end of the procedure. Both values were within the normal range in the EtCO2 monitoring group. The number of airway interventions performed was significantly higher in the EtCO2 monitoring group (9.8 ±â€Š1.8 vs. 1.9 ±â€Š1.0; P < 0.0001). Apnoea occurred significantly less often in the EtCO2 monitoring group (0 vs. 10%; P < 0.0001) and recovery time was shorter (9.9 ±â€Š1.4 vs. 11.4 ±â€Š2.1 min; P = 0.048). CONCLUSION: The addition of EtCO2 monitoring to standard monitoring during propofol-based sedation can improve patient safety by decreasing the incidence of CO2 retention, and therefore the risk of hypoxaemia through early recognition of apnoea, and can also shorten recovery time. TRIAL REGISTRATION: This trial is registered with http://www.chictr.org.cn (ChiCTR-INR-17011537).

Hydrogen-rich saline attenuates isoflurane-induced caspase-3 activation and cognitive impairment via inhibition of isoflurane-induced oxidative stress, mitochondrial dysfunction, and reduction in ATP levels.

OBJECTIVES: The inhaled general anesthetic isoflurane has been shown to induce caspase-3 activation in vitro and in vivo. The underlying mechanisms and functional consequences of this activity remain unclear. Isoflurane can induce caspase-3 activation by causing accumulation of reactive oxygen species (ROS), mitochondrial dysfunction, and reduction in adenosine triphosphate (ATP) levels. This study aimed to investigate the protective effect of hydrogen, a novel antioxidant, against isoflurane-induced caspase-3 activation and cognitive impairment. METHODS: H4 human neuroglioma cells overexpressing human amyloid precursor protein were treated with saline or hydrogen-rich saline (HS, 300 µM), with or without 2% isoflurane, for 6 h or 3 h. Western blot analysis, fluorescence assays, and a mitochondrial swelling assay were used to evaluate caspase-3 activation, levels of ROS and ATP, and mitochondrial function. The effect of the interaction of isoflurane (1.4% for 2 h) and HS (5 mL/kg) on cognitive function in mice was also evaluated using a fear conditioning test. RESULTS: We found that HS attenuated isoflurane-induced caspase-3 activation. Moreover, HS treatment mitigated isoflurane-induced ROS accumulation, opening of mitochondrial permeability transition pores, reduction in mitochondrial membrane potential, and reduction in cellular ATP levels. Finally, HS significantly alleviated isoflurane-induced cognitive impairment in mice. CONCLUSIONS: Our results suggest that HS attenuates isoflurane-induced caspase-3 activation and cognitive impairment via inhibition of isoflurane-induced oxidative stress, mitochondrial dysfunction, and reduction in ATP levels. These findings warrant further research into the underlying mechanisms of this activity, and indicate that HS has the potential to attenuate anesthesia neurotoxicity.

Role of interleukin-4, the chemokine CCL3 and its receptor CCR5 in neuropathic pain.

Cytokines and chemokines are involved in chronic pain syndromes, and their expression is altered in injury-induced neuronal pain pathways. However, the exact cytokines/chemokines involved and their mechanism of action remain to be determined. In this study, we investigated the role of interleukin-4 and the chemokine/chemokine receptor pair CCL3/CCR5 in a mouse model of chronic constriction injury (CCI)-induced neuropathic pain. Neuropathic pain was induced by surgical ligation of the sciatic nerve and assessed by measuring thermal hyperalgesia and mechanical allodynia using a plantar test and a dynamic plantar esthesiometer. The underlying mechanisms were investigated by real-time quantitative reverse transcription polymerase chain reaction, western blotting, immunohistochemistry, ELISA, and histopathology. CCI-induced neuropathic pain was associated with CCL3 and CCR5 upregulation and microglial activation. Intrathecal injection of the anti-inflammatory cytokine interleukin-4 or CCL3-neutralizing antibody alleviated CCI-induced inflammation, suppressing the CCI-induced upregulation of tumor necrosis factor-α and interleukin-1ß in the serum and spinal cord, restoring the CCI-induced upregulation of CCL3 and CCR5, and suppressing the CCI-induced activation of p38 mitogen-activated protein kinase. Knockout of CCR5 also suppressed CCI-induced neuropathic pain. Since the upregulation of chemokines and cytokines is directly or indirectly involved in chronic pain after nerve injury, these molecules are potential therapeutic targets in the treatment of neuropathic pain.

Chrysophanol affords neuroprotection against microglial activation and free radical-mediated oxidative damage in BV2 murine microglia.

In this study, chrysophanol, isolated from a marine fungus, was examined for its protective effects against inflammatory responses and oxidative stress in BV2 microglia. Chrysophanol was studied to assess its capabilities of protecting against lipopolysaccharide (LPS)-induced inflammatory responses in BV2 cells. It was found that chrysophanol reduced the level of nitric oxide (NO) and prostaglandin-E2 (PGE2) production by diminishing reducing the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). Assessment of the inhibitory activities of chrysophanol on the generation of pro-inflammatory cytokines was also performed. Furthermore, Chrysophanol treatment significantly reduced intracellular reactive oxygen species (ROS)-mediated cell damage and inhibited DNA oxidation in BV2 cells. Moreover, antioxidative mechanisms by of chrysophanol were evaluated investigated by measuring the expression levels of antioxidative enzymes such superoxide dismutase (SOD) and glutathione (GSH). Therefore, results suggested that chrysophanol has potential antioxidant and anti-inflammatory activities in microglia and further might be a useful therapeutic agent for the treatment of neurodegenerative diseases.

Clinical research of percutaneous bilateral splanchnic nerve lesion for pain relief in patients with pancreatic cancer under X-ray guidance.

OBJECTIVE: to observe the therapeutic effects of percutaneous bilateral splanchnic nerves block in patients with intractable pain due to pancreatic cancer. METHODS: twenty-fourpatients (advanced pancreatic cancer) with intractable pain were enrolled in the research. Through approach of the edge of T11 vertebral body with double-needle technique, the researchers carried out the bilateral lesion of the greater and the lesser splanchnic nerve with absolute ethyl alcohol under X-ray guidance. Follow-up was six months. Numerical rating scale (NRS) and quality of life (QOL) were all assessed pre- and post-procedure (1 d, 1 w, 2 w, 1 m, 2 m, 3 m, 4 m, 5 m, 6 m). The daily morphine consumption was recorded. RESULTS: NRS and daily morphine consumption decreased when compared to pre-procedure while QOL increased. These differences were found to be statistically significant (P<0.05). 9 patients suffered from diarrhea temporally and recoveredin one week. CONCLUSION: Percutaneous bilateral splanchnic nerves lesion under X-ray guidancecan treat intractable pain caused by pancreatic cancer and improve patients'life quality with minor complication.

Ovariectomy modulation of morphine analgesia of neuropathic pain is associated with the change of K(+)-Cl(-) cotransporter 2 protein level in spinal dorsal horn.

Sex differences in opioid analgesia have been confirmed both in clinical and experimental studies. Gonadal hormones (estrogens in particular) have a great role in this process. However, the mechanisms that underlie these sex differences are not very clear. In this study, we used K(+)-Cl(-) cotransporter 2 (KCC2) as a molecule target to investigate the mechanism underlying the phenomenon. Sprague-Dawley rats were randomly assigned to ovariectomy (OVX)+morphine group, OVX+Saline group, sham surgery (OVX-sham)+morphine group and OVX-sham+saline group. All the rats received SNI surgery three weeks after ovariectomy. We used von Frey values as a sign of neuropathic pain. On PO day 14, 1 µg morphine or the vehicle saline was administered intrathecally via a PE-10 catheter formerly implanted. Hindpaw withdrawal threshold was determined before and 30, 60, 90, 120, 150, 180 min after drugs injection. The L4-L5 segments of the spinal cord were removed and immunoblotted for KCC2 protein at the time of 2 and 3 h after drugs administration. We find that ovariectomy can regulate the sensitivity to morphine analgesia of neuropathic pain and KCC2 protein level will change in the spinal dorsal horn.

Neuronal apoptosis in morphine addiction and its molecular mechanism.

OBJECTIVE: This study aimed to investigate neuronal apoptosis and expression of apoptosis related proteins (Fas, Caspase-3 and Bcl-2) in the brain of rates with morphine addiction. METHODS: A total of 48 adult male Sprague-Dawley rats weighing 190-210 g were randomly divided into 3 groups (n=16 per group): morphine addiction group, morphine abstinence group and control group. Rats in the addiction group and the abstinence group were intraperitoneally treated with morphine for 13 days to induce morphine addiction. In abstinence group, rats were then intraperitoneally treated with naloxone at 5 mg/kg to induce abstinence for 30 min. Rats in the control group were injected with normal saline. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) was employed to detect apoptotic cells. Immunohistochemistry and Western blot assay were performed to determine the expressions of Fas, Bcl-2 and Caspase-3 in the hippocampus. RESULTS: When compared with the control group, the proportion of apoptotic neurons increased significantly in the addiction group and the abstinence group (P<0.01), accompanied by significantly increased expressions of Fas and Caspase-3 (P<0.01) and markedly decreased Bcl-2 expression (P<0.01) in the hippocampuse. However, no significant differences were observed between the addiction and the abstinence group (P>0.05). CONCLUSION: Long term use of morphine can induce neuronal apoptosis in the brain by increasing the expressions of pro-apoptotic Fas and Caspase-3 and decreasing the anti-apoptotic Bcl-2 expression, which might be one of mechanisms underlying the opiate-induced neuronal damage.

Effect of rapid plasma volume expansion during anesthesia induction on haemodynamics and oxygen balance in patients undergoing gastrointestinal surgery.

AIMS: To investigate the reasonable dose of Voluven for rapid plasma volume expansion during the anaesthesia induction patients receiving gastrointestinal surgery. METHODS: Sixty patients were randomly divided into three groups (n=20): Group A (5 ml/kg), Group B (7 ml/kg) and Group C (9 ml/kg). HES 130/0.4 was intravenously transfused at a rate of 0.3 ml/kg/min) at 30 min before anaesthesia induction. Besides standard haemodynamic monitoring, cardiac index (CI), systemic vascular resistance index (SVRI) and stroke volume variation (SVV) was continuously detected with the FloTrac/Vigileo system. Haemodynamic variables were recorded immediately before fluid transfusion (T0), immediately before induction (T1), immediately before intubation (T2), immediately after intubation (T3) and 5 min, 10 min, 20 min and 60 min after intubation (T4-T7). Arterial and venous blood was collected for blood gas analysis, Hb and Hct before volume expansion (t0), immediately after volume expansion (t1) and at 1 h after volume expansion (t2). Oxygen delivery (DO2), oxygen extraction ratio (ERO2) and volume expansion rate were calculated. RESULTS: 1) MAP and CI decreased in Group A in T2~T7 and remained changed in Group B and C. 2) CVP increased in three groups after fluid infusion without significant difference. 3) The decrease in SVRI was more obvious in Group B and C than that in Group A after induction and more obvious in Group C than in Group B in T2-T4 and T6~T7. 4) SVV was lower in Group B and C than that in Group A after intubation, and lower in Group C than that in Group B in T3-T6. 5) Hb and Hct decreased after fluid infusion, and the decrease in Hb and Hct was in the order of C>B>A. 6) Volume expansion rate was in the order of C>B>A. 7) ScvO2, PaO2 and DO2 increased in three groups after fluid infusion and the increase in DO2 was in the order of C>B>A. CONCLUSIONS: Rapid plasma volume expansion with Voluven at 7-9 ml/kg can prevent haemodynamic fluctuation during anaesthesia induction, maintain the balance between oxygen supply and oxygen consumption during gastrointestinal surgery, and Voluven at 9 ml/kg can improve the oxygen delivery.