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Recently, increasingly growing efforts have been devoted to incorporating dynamic covalent bonds into covalently crosslinked networks to address the persistent trade-offs between chemical crosslinking and malleability. Herein, a series of dynamic aminal bond crosslinked polybutadiene rubbers (PAPB) are prepared by crosslinking aldehyde group-terminated polybutadiene rubber (APB) with piperazine. By varying the molecular weight of APB, the crosslinking density of PAPB is changed, which offers the platform to regulate the mechanical characteristics and dynamic properties. Specially, with the decrease of APB molecular weight, i.e. with the increase of crosslinking density, the modulus of PAPB gradually increases while the elongation at break conversely decreases, and the activation energy for network rearrangement initially decreases and then increases. The resultant PAPB exhibit vitrimer-like behaviors that can alter the network topologies at elevated temperatures without the loss of structural integrity through dissociative aminal exchange reactions, while the protic source can accelerate aminal dissociation and result in network dissolution even at room temperature. Due to the aminal exchange, PAPB are thermally malleable and can almost restore the original mechanical characteristics after recycling; besides, they are capable of healing at a relatively low crosslinking density.

Patients suffering with functional somatic pain syndromes such as temporomandibular disorders (TMD) and fibromyalgia syndrome (FMS) have some similar symptoms, but the underlying cause is still unclear. The purpose of this study was to investigate whether 5-HT2A and 5-HT2C receptors in the spinal cord contribute to somatic hyperalgesia induced by orofacial inflammation combined with different modes of stress. Ovariectomized rats were injected subcutaneously with estradiol and bilateral masseter muscles were injected with complete Freund’s adjuvant followed by stress. Somatic sensitivity was assessed with thermal and mechanical stimulation. The anxiety- and depression-like behaviors were measured by immobility time, sucrose preference, elevated plus maze and open field tests. The expression of 5-HT2A and 5-HT2C receptors in the spinal cord was examined by Western blot. Orofacial inflammation combined with 11 day forced swim stress (FSS) induced persistent mechanical allodynia for 15 days and thermal hyperalgesia for 2 days. The mechanical and thermal hyperalgesia lasted for 43 days and 30 days respectively following orofacial inflammation combined with 11 day heterotypic stress. Orofacial inflammation combined with stress induced anxiety- and depression-like behaviors. The expression of 5-HT2A and 5-HT2C receptors significantly decreased in the orofacial inflammation combined with stress groups. Intrathecal injection of 5-HT2A or 5-HT2C receptor agonist reversed somatic hyperalgesia. The results suggest that down-regulation of 5-HT2A and 5-HT2C receptors in the spinal cord contributes to somatic hyperalgesia induced by orofacial inflammation combined with stress, indicating that 5-HT2A and 5-HT2C receptors may be potential targets in the treatment of TMD comorbid with FMS.

To evaluate the clinical significance of tumor response to induction chemotherapy (IC) in locoregionally advanced nasopharyngeal carcinoma (LANPC) patients and further to develop a nomogram for predicting survival prognosis.A total of 498 patients with stage III-IVA NPC applying IC and concurrent chemotherapy were reviewed (training cohort, n = 376; validation cohort, n = 122).Tumor response was an independent predictor for clinical outcomes. The nomogram included age, N stage, pretreatment Epstein-Barr virus DNA, lymphocyte-to-monocyte ratio, and tumor response achieved an ideal C-index of 0.703 (95% CI 0.655-0.751) in the validation cohort for predicting overall survival (OS), which outperformed than that of the TNM system alone (C-index, 0.670, 95% CI: 0.622-0.718). In addition, the nomogram could successfully classified patients into different risk groups.We established and validated a precise and convenient nomogram based on tumor response for predicting the OS of LANPC patients.

Structural optimization using plant secondary metabolites as templates is one of the important approach to discover pesticide molecules with novel skeletons. Xanthatin, a natural sesquiterpene lactone isolated from the Xanthium plants (Family: Compositae), exhibits important biological properties. In this work, a series of Michael-type amino derivatives were prepared from xanthatin and their structures were characterized by 1H NMR, 13C NMR and HR-MS, and their antifungal activities against several phytopathogenic fungi were evaluated according to the spore germination method and mycelium growth rate method in vitro. The results illustrated that compounds 2g (IC50 = 78.91 µg/mL) and 2o (IC50 = 64.51 µg/mL) exhibited more promising inhibition activity against spores of F. solani than precursor xanthatin, compounds 2g, 2l, and 2r exhibited remarkable antifungal effect on C. mandshurica with the average inhibition rates (AIRs) > 90%, whereas the AIR of xanthatin was only 59.34%. Meanwhile, the preliminary structure-activity relationships suggested that the amino containing 2-methoxyethyl or 4-chlorophenylmethyl group appended in the C-13 position of xanthatin could yield potential compounds against fungal spores, and the exocyclic double bond of xanthatin is essential to maintain its mycelial growth inhibitory activity. Therefore, the aforementioned findings indicate that partial xanthatin amino-derivatives could be considered for further exploration as the potential lead structures toward development of the new environmentally friendly fungicidal candidates for sustainable crop protection.

Epigenetic regulation of gene expression has been implicated in the development of chronic pain. However, little is known about whether this regulation is involved in the development and treatment of chronic pain comorbidities such as fibromyalgia syndrome (FMS) and temporomandibular disorder (TMD), a comorbidity predominantly occurring among women. Here we explored the impact of the histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) on somatic hyperalgesia induced by stress or stress combined with orofacial inflammation, which mimicked the comorbidity of FMS and TMD in rats. Our data showed that somatic thermal hyperalgesia and mechanical allodynia induced by both conditions were completely prevented by intrathecal injection of SAHA, which upregulated 5-HT

Patients suffering with functional somatic pain syndromes such as temporomandibular disorders (TMD) and fibromyalgia syndrome (FMS) have some similar symptoms, but the underlying cause is still unclear. The purpose of this study was to investigate whether 5-HT

In some chronic primary pain conditions such as temporomandibular disorder (TMD) and fibromyalgia syndrome (FMS), mild or chronic stress enhances pain. TMD and FMS often occur together, but the underlying mechanisms are unclear. The purpose of this study was to investigate the role of cholecystokinin (CCK) in the spinal cord in somatic hyperalgesia induced by orofacial inflammation combined with stress. Somatic hyperalgesia was detected by the thermal withdrawal latency and mechanical withdrawal threshold. The expression of CCK(1) receptors, CCK(2) receptors, ERK1/2 and p-ERK1/2 in the spinal cord was examined by Western blot. After the stimulation of orofacial inflammation combined with 3 day forced swim, the expression of CCK(2) receptors and p-ERK1/2 protein in the L4-L5 spinal dorsal horn increased significantly, while the expression of CCK(1) receptors and ERK1/2 protein remained unchanged. Intrathecal injection of the CCK(2) receptor antagonist YM-022 or mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitor PD98059 blocked somatic hyperalgesia induced by orofacial inflammation combined with stress. Intrathecal administration of the MEK inhibitor blocked somatic sensitization caused by the CCK receptor agonist CCK8. The CCK(2) receptor antagonist YM-022 significantly reduced the expression of p-ERK1/2. These data indicate that upregulation of CCK(2) receptors through the MAPK pathway contributes to somatic hyperalgesia in this comorbid pain model. Thus, CCK(2) receptors and MAPK pathway may be potential targets for the treatment of TMD comorbid with FMS.

Sodium valproate (VPA) has analgesic effects in clinical and experimental studies, but the mechanisms are still unclear. The present study examined the effects of VPA on stress-induced somatic hyperalgesia and visceral hypersensitivity and the role of 5-HT(2C) receptors in the spinal cord. Repeated 3 day forced swim (FS) significantly reduced the thermal withdrawal latency and mechanical withdrawal threshold, and increased the magnitude of the visceromotor response to colorectal distention compared to the baseline values in rats. The somatic hyperalgesia and visceral hypersensitivity were accompanied by significant down-regulation of 5-HT(2C) receptor expression in the L4-L5 and L6-S1 dorsal spinal cord. Intraperitoneal administration of VPA (300 mg/kg) before each FS and 1 day post FS prevented the development of somatic hyperalgesia and visceral hypersensitivity induced by FS stress, as well as down-regulation of 5-HT(2C) receptors in the spinal cord. The reversal of somatic hyperalgesia and visceral hypersensitivity by VPA in FS rats was blocked by intrathecal administration of the selective 5-HT(2C) receptor antagonist RS-102221 (30 μg/10 μL) 30 min after each VPA injection. The results suggest that VPA attenuates FS-induced somatic hyperalgesia and visceral hypersensitivity by restoring down-regulated function of 5-HT(2C) receptors in the spinal cord.

Chronic primary pain (CPP) is a group of diseases with long-term pain and functional disorders but without structural or specific tissue pathologies. CPP is becoming a serious health problem in clinical practice due to the unknown cause of intractable pain and high cost of health care yet has not been satisfactorily addressed. During the past decades, a significant role for the descending pain modulation and alterations due to specific diseases of CPP has been emphasized. It has been widely established that central sensitization and alterations in neuroplasticity induced by the enhancement of descending pain facilitation and/or the impairment of descending pain inhibition can explain many chronic pain states including CPP. The descending serotonergic neurons in the raphe nuclei target receptors along the descending pain circuits and exert either pro- or antinociceptive effects in different pain conditions. In this review, we summarize the possible underlying descending pain regulation mechanisms in CPP and the role of serotonin, thus providing evidence for potential application of analgesic medications based on the serotonergic system in CPP patients.

Sodium valproate (VPA) has analgesic effects in clinical and experimental studies, but the mechanisms are still unclear. The present study examined the effects of VPA on stress-induced somatic hyperalgesia and visceral hypersensitivity and the role of 5-HT2C receptors in the spinal cord. Repeated 3 day forced swim (FS) significantly reduced the thermal withdrawal latency and mechanical withdrawal threshold, and increased the magnitude of the visceromotor response to colorectal distention compared to the baseline values in rats. The somatic hyperalgesia and visceral hypersensitivity were accompanied by significant down-regulation of 5-HT2C receptor expression in the L4-L5 and L6-S1 dorsal spinal cord. Intraperitoneal administration of VPA (300 mg/kg) before each FS and 1 day post FS prevented the development of somatic hyperalgesia and visceral hypersensitivity induced by FS stress, as well as down-regulation of 5-HT2C receptors in the spinal cord. The reversal of somatic hyperalgesia and visceral hypersensitivity by VPA in FS rats was blocked by intrathecal administration of the selective 5-HT2C receptor antagonist RS-102221 (30 μg/10 μL) 30 min after each VPA injection. The results suggest that VPA attenuates FS-induced somatic hyperalgesia and visceral hypersensitivity by restoring down-regulated function of 5-HT2C receptors in the spinal cord.

Experimental evidence suggests the involvement of the brain dopaminergic system in learning and memory processes, although the associated molecular mechanism has yet to be fully characterized. Memory formation occurs via a number of signaling pathways associated with activation of many synaptic plasticity-related proteins, including the N-Methyl-D-aspartic acid (NMDA) receptor, Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), mitogen-activated protein kinases (MAPKs) and the cAMP-response element binding protein (CREB). To evaluate the roles of dopamine D(1) and D(3) receptors in spatial learning and memory and underlying molecular events, we have used genetically modified mice carrying either the D(1) or D(3) receptor gene mutations to explore the intracellular signaling pathways using Morris water maze (MWM) tasks. We show that D(1) receptor mutant mice do not acquire spatial memory and do not show hippocampal activation of extracellular signal-regulated kinase (ERK) compared to wild-type mice. D(3) receptor mutant mice exhibit apparent normal learning abilities in the MWM test and normal activation of MAPK signaling. Furthermore, activation of the NMDA receptor R1 subunit (NR1), CaMKII and CREB in the hippocampus is also significantly lower in D(1) receptor mutant mice compared to wild-type and D(3) receptor mutant mice. These results suggest that dopamine D(1) but not D(3) receptor is critical for spatial learning. D(1) receptor-mediated signaling, associated with activation of NR1, CaMKII, ERK and CREB, is highly involved in the encoding of spatial learning and memory.

To evaluate the therapeutic effects of locked supracondylar intramedullary nail and bolt for treating comminuted fracture in the distal end of the femur.Forty-two patients (including 31 male and 11 female patients) with supracondylar and intercondylar fractures, classified into type C1 in 20 cases and type C2 in 22 cases according to AO classification, were treated with retrograde intramedullary nail and bolt.The follow-up period ranged from 3 to 18 months and the average time of bone healing was 4.6 months. Assessed by functional scoring, the results were excellent in 31 patients, good in 10, and acceptable in 1, with the rate of excellent result as high as 97.6%.Retrograde intramedullary nail and bolt can be ideal for treating supracondylar and intercondylar fractures. The bolt can effectively control the dissociation of the intercondylar fractures and good functional recovery of the knee joint can be achieved through early functional training.