Promoter variations of ClERF1 gene determines flesh firmness in watermelon.

BACKGROUND: Flesh firmness is a critical factor that influences fruit storability, shelf-life and consumer's preference as well. However, less is known about the key genetic factors that are associated with flesh firmness in fresh fruits like watermelon. RESULTS: In this study, through bulk segregant analysis (BSA-seq), we identified a quantitative trait locus (QTL) that influenced variations in flesh firmness among recombinant inbred lines (RIL) developed from cross between the Citrullus mucosospermus accession ZJU152 with hard-flesh and Citrullus lanatus accession ZJU163 with soft-flesh. Fine mapping and sequence variations analyses revealed that ethylene-responsive factor 1 (ClERF1) was the most likely candidate gene for watermelon flesh firmness. Furthermore, several variations existed in the promoter region between ClERF1 of two parents, and significantly higher expressions of ClERF1 were found in hard-flesh ZJU152 compared with soft-flesh ZJU163 at key developmental stages. DUAL-LUC and GUS assays suggested much stronger promoter activity in ZJU152 over ZJU163. In addition, the kompetitive allele-specific PCR (KASP) genotyping datasets of RIL populations and germplasm accessions further supported ClERF1 as a possible candidate gene for fruit flesh firmness variability and the hard-flesh genotype might only exist in wild species C. mucosospermus. Through yeast one-hybrid (Y1H) and dual luciferase assay, we found that ClERF1 could directly bind to the promoters of auxin-responsive protein (ClAux/IAA) and exostosin family protein (ClEXT) and positively regulated their expressions influencing fruit ripening and cell wall biosynthesis. CONCLUSIONS: Our results indicate that ClERF1 encoding an ethylene-responsive factor 1 is associated with flesh firmness in watermelon and provide mechanistic insight into the regulation of flesh firmness, and the ClERF1 gene is potentially applicable to the molecular improvement of fruit-flesh firmness by design breeding.

Sema3A secreted by sensory nerve induces bone formation under mechanical loads.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling. Here, we focused on the role of Semaphorin 3A (Sema3A), expressed by sensory nerves, in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement (OTM) model. Firstly, bone formation was activated after the 3rd day of OTM, coinciding with a decrease in sensory nerves and an increase in pain threshold. Sema3A, rather than nerve growth factor (NGF), highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM. Moreover, in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells (hPDLCs) within 24 hours. Furthermore, exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload. Mechanistically, Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway, maintaining mitochondrial dynamics as mitochondrial fusion. Therefore, Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation, both as a pain-sensitive analgesic and a positive regulator for bone formation.

Allelic variations of ClACO gene improve nitrogen uptake via ethylene-mediated root architecture in watermelon.

KEY MESSAGE: The ClACO gene encoding 1-aminocyclopropane-1-carboxylate oxidase enabled highly efficient 15N uptake in watermelon. Nitrogen is one of the most essential nutrient elements that play a pivotal role in regulating plant growth and development for crop productivity. Elucidating the genetic basis of high nitrogen uptake is the key to improve nitrogen use efficiency for sustainable agricultural productivity. Whereas previous researches on nitrogen absorption process are mainly focused on a few model plants or crops. To date, the causal genes that determine the efficient nitrogen uptake of watermelon have not been mapped and remains largely unknown. Here, we fine-mapped the 1-aminocyclopropane-1-carboxylate oxidase (ClACO) gene associated with nitrogen uptake efficiency in watermelon via bulked segregant analysis (BSA). The variations in the ClACO gene led to the changes of gene expression levels between two watermelon accessions with different nitrogen uptake efficiencies. Intriguingly, in terms of the transcript abundance of ClACO, it was concomitant with significant differences in ethylene evolutions in roots and root architectures between the two accessions and among the different genotypic offsprings of the recombinant BC2F1(ZJU132)-18. These findings suggest that ethylene as a negative regulator altered nitrogen uptake efficiency in watermelon by controlling root development. In conclusion, our current study will provide valuable target gene for precise breeding of 'green' watermelon varieties with high-nitrogen uptake efficiencies.

Detecting representative characteristics of different genders using intraoral photographs: a deep learning model with interpretation of gradient-weighted class activation mapping.

BACKGROUND: Sexual dimorphism is obvious not only in the overall architecture of human body, but also in intraoral details. Many studies have found a correlation between gender and morphometric features of teeth, such as mesio-distal diameter, buccal-lingual diameter and height. However, it's still difficult to detect gender through the observation of intraoral photographs, with accuracy around 50%. The purpose of this study was to explore the possibility of automatically telling gender from intraoral photographs by deep neural network, and to provide a novel angle for individual oral treatment. METHODS: A deep learning model based on R-net was proposed, using the largest dataset (10,000 intraoral images) to support the automatic detection of gender. In order to reverse analyze the classification basis of neural network, Gradient-weighted Class Activation Mapping (Grad-CAM) was used in the second step, exploring anatomical factors associated with gender recognizability. The simulated modification of images based on features suggested was then conducted to verify the importance of characteristics between two genders. Precision (specificity), recall (sensitivity) and receiver operating characteristic (ROC) curves were used to evaluate the performance of our network. Chi-square test was used to evaluate intergroup difference. A value of p < 0.05 was considered statistically significant. RESULTS: The deep learning model showed a strong ability to learn features from intraoral images compared with human experts, with an accuracy of 86.5% and 82.5% in uncropped image data group and cropped image data group respectively. Compared with hard tissue exposed in the mouth, gender difference in areas covered by soft tissue was easier to identify, and more significant in mandibular region than in maxillary region. For photographs with simulated removal of lips and basal bone along with overlapping gingiva, mandibular anterior teeth had similar importance for sex determination as maxillary anterior teeth. CONCLUSIONS: Deep learning method could detect gender from intraoral photographs with high efficiency and accuracy. With assistance of Grad-CAM, the classification basis of neural network was deciphered, which provided a more precise entry point for individualization of prosthodontic, periodontal and orthodontic treatments.

Artificial intelligence system for automated landmark localization and analysis of cephalometry.

OBJECTIVES: Cephalometric analysis is essential for diagnosis, treatment planning and outcome assessment of orthodontics and orthognathic surgery. Utilizing artificial intelligence (AI) to achieve automated landmark localization has proved feasible and convenient. However, current systems remain insufficient for clinical application, as patients exhibit various malocclusions in cephalograms produced by different manufacturers while limited cephalograms were applied to train AI in these systems. METHODS: A robust and clinically applicable AI system was proposed for automatic cephalometric analysis. First, 9870 cephalograms taken by different radiography machines with various malocclusions of patients were collected from 20 medical institutions. Then 30 landmarks of all these cephalogram samples were manually annotated to train an AI system, composed of a two-stage convolutional neural network and a software-as-a-service system. Further, more than 100 orthodontists participated to refine the AI-output landmark localizations and retrain this system. RESULTS: The average landmark prediction error of this system was as low as 0.94 ± 0.74 mm and the system achieved an average classification accuracy of 89.33%. CONCLUSIONS: An automatic cephalometric analysis system based on convolutional neural network was proposed, which can realize automatic landmark location and cephalometric measurements classification. This system showed promise in improving diagnostic efficiency in clinical circumstances.

Chromosome-level genome assembly of bunching onion illuminates genome evolution and flavor formation in Allium crops.

The Allium genus is cultivated globally as vegetables, condiments, or medicinal plants and is characterized by large genomes and strong pungency. However, the genome evolution and genomic basis underlying their unique flavor formation remain poorly understood. Herein, we report an 11.27-Gb chromosome-scale genome assembly for bunching onion (A. fistulosum). The uneven bursts of long-terminal repeats contribute to diversity in genome constituents, and dispersed duplication events largely account for gene expansion in Allium genomes. The extensive duplication and differentiation of alliinase and lachrymatory factor synthase manifest as important evolutionary events during flavor formation in Allium crops. Furthermore, differential selective preference for flavor-related genes likely lead to the variations in isoalliin content in bunching onions. Moreover, we reveal that China is the origin and domestication center for bunching onions. Our findings provide insights into Allium genome evolution, flavor formation and domestication history and enable future genome-assisted breeding of important traits in these crops.

Automated calibration system for length measurement of lateral cephalometry based on deep learning.

Objective. Cephalometric analysis has been significantly facilitated by artificial intelligence (AI) in recent years. For digital cephalograms, linear measurements are conducted based on the length calibration process, which has not been automatized in current AI-based systems. Therefore, this study aimed to develop an automated calibration system for lateral cephalometry to conduct linear measurements more efficiently.Approach. This system was based on deep learning algorithms and medical priors of a stable structure, the anterior cranial base (Sella-Nasion). First, a two-stage cascade convolutional neural network was constructed based on 2860 cephalograms to locate sella, nasion, and 2 ruler points in regions of interest. Further, Sella-Nasion distance was applied to estimate the distance between ruler points, and then pixels size of cephalograms was attained for linear measurements. The accuracy of automated landmark localization, ruler length prediction, and linear measurement based on automated calibration was evaluated with statistical analysis.Main results. First, for AI-located points, 99.6% ofSand 86% ofNpoints deviated less than 2 mm from the ground truth, and 99% of ruler points deviated less than 0.3 mm from the ground truth. Also, this system correctly predicted the ruler length of 98.95% of samples. Based on automated calibration, 11 linear cephalometric measurements of the test set showed no difference from manual calibration (p > 0.05).Significance. This system was the first reported in the literature to conduct automated calibration with high accuracy and showed high potential for clinical application in cephalometric analysis.

An allelic variant in the ACS7 gene promotes primary root growth in watermelon.

KEY MESSAGE: Gene mining in a C. lanatus × C. amarus population revealed one gene, ACS7, linked to primary root elongation in watermelon. Watermelon is a xerophytic crop characterized by a long primary root and robust lateral roots. Therefore, watermelon serves as an excellent model for studying root elongation and development. However, the genetic mechanism underlying the primary root elongation in watermelon remains unknown. Herein, through bulk segregant analysis we identified a genetic locus, qPRL.Chr03, controlling primary root length (PRL) using two different watermelon species (Citrullus lanatus and Citrullus amarus) that differ in their root architecture. Fine mapping revealed that xaa-Pro dipeptidase and 1-aminocyclopropane-1-carboxylate synthase 7 (ACS7) are candidate regulators of the primary root growth. Allelic variation in the delimited region among 193 watermelon accessions indicated that the long-root alleles might only exist in C. amarus. Interestingly, the discrepancy in PRL among the C. amarus accessions was clearly associated with a nonsynonymous single nucleotide polymorphism variant within the ACS7 gene. The ACS7 expression and ethylene levels in the primary root tips suggested that ethylene is a negative regulator of root elongation in watermelon, as supported by the application of 1-aminocyclopropane-1-carboxylate (ACC, the ethylene precursor) or 2-aminoethoxyvinyl glycine (AVG, an ACS inhibitor). To the best of our knowledge, these findings provide the first description of the genetic basis of root elongation in watermelon. The detected markers of the ACS7 gene will facilitate marker-assisted selection for the PRL trait to improve water and nutrient use efficacy in watermelon and beyond.

The effect of matrix stiffness on the chondrogenic differentiation of mesenchymal stem cells.

Articular cartilage is one of the most important weight-bearing components in human body, thus the chondrogenesis of stem cells is reactive to many intracellular and extracellular mechanical signals. As a unique physical cue, matrix stiffness plays an integral role in commitment of stem cell fate. However, when examining the downstream effects of matrix stiffness, most studies used different soluble factors to assist physical inducing process, which may mask the chondrogenic effects of matrix stiffness. Here we fabricated polyacrylamide (PAAm) hydrogels with gradient stiffness to unravel the role of matrix stiffness in chondrogenic process of mesenchymal stem cells (MSCs), with or without TGF-ß3 as induction factor. The results showed that with micromass culture mimicking relatively high cell density in vivo, the chondrogenic differentiation of MSCs can be promoted by soft substrates (about 0.5 kPa) independently with assembled cytoskeleton. Further analysis indicated that addition of TGF-ß3 generally increased expression level of cartilage-related markers and masked the stiffness-derived expression pattern of hypertrophic markers. These results demonstrate how mechanical cues experienced in developmental context regulate commitment of stem cell fate and have significant impact on the design of tissue regeneration materials.

Enhanced PDGFR/Wnt/ß-catenin activity of mesenchymal stem cells with high migration ability rescue bone loss of osteoporosis.

Osteoporosis is a widespread disease characterized by bone mass loss and microarchitectural deterioration. The side effects of clinical drugs make mesenchymal stem cells (MSCs)-based therapy gain increasing focus in the treatment of osteoporosis. MSCs need to migrate to the site of damage and undergo differentiation in order to participate in the subsequent bone repair process. Therefore, the homing ability of MSCs may be related to the repair ability. Here, we proposed a novel method to screen MSCs with high migration capacity and confirmed that these MSCs exhibited higher osteogenic differentiation ability both in vivo and in vitro. Further results indicated that MSCs with high migration ability could partly rescue the bone loss of ovarectomized (OVX) rats. Higher expression of Platelet-derived growth factors receptor ß- (PDGFRß) and more nuclear transduction of ß-catenin in MSCs with high migration ability may be responsible for biological functions. This article may provide a method to improve the efficacy of MSCs-based therapy in the clinic.

Hyperactive Akt-mTOR pathway as a therapeutic target for pain hypersensitivity in Cntnap2-deficient mice.

Contactin-associated protein-like 2 (CNTNAP2 or CASPR2) is a neuronal transmembrane protein of the neurexin superfamily that is involved in many neurological diseases, such as autism and pain hypersensitivity. We recently found that Cntnap2-/- mice showed elevated Akt-mTOR activity in the brain, and suppression of the Akt-mTOR pathway rescued the social deficit in Cntnap2-/- mice. In this study, we found that the dorsal root ganglion (DRG) from Cntnap2-/- mice also showed hyperactive Akt-mTOR signaling. Treatment with the Akt inhibitor LY94002 or the mTOR inhibitor rapamycin attenuated pain-related hypersensitivity to noxious mechanical stimuli, heat, and inflammatory substances. Further, suppression of mTOR signaling by rapamycin decreased DRG neuronal hyperexcitability. We further indicated that treatment with the FDA-approved drug metformin normalized the hyperactive Akt-mTOR signaling, and attenuated pain-related hypersensitivity in Cntnap2-/- mice. Our results thus identified hyperactive Akt-mTOR signaling pathway as a promising therapeutic target for pain-related hypersensitivity in patients with dysfunction of CNTNAP2.

Enhancement of acid-sensing ion channel activity by prostaglandin E2 in rat dorsal root ganglion neurons.

Prostaglandin E2 (PGE2) and proton are typical inflammatory mediators. They play a major role in pain processing and hypersensitivity through activating their cognate receptors expressed in terminals of nociceptive sensory neurons. However, it remains unclear whether there is an interaction between PGE2 receptors and proton-activated acid-sensing ion channels (ASICs). Herein, we show that PGE2 enhanced the functional activity of ASICs in rat dorsal root ganglion (DRG) neurons through EP1 and EP4 receptors. In the present study, PGE2 concentration-dependently increased ASIC currents in DRG neurons. It shifted the proton concentration-response curve upwards, without change in the apparent affinity of proton for ASICs. Moreover, PGE2 enhancement of ASIC currents was partially blocked by EP1 or EP4 receptor antagonist. PGE2 failed to enhance ASIC currents when simultaneous blockade of both EP1 and EP4 receptors. PGE2 enhancement was partially suppressed after inhibition of intracellular PKC or PKA signaling, and completely disappeared after concurrent blockade of both PKC and PKA signaling. PGE2 increased significantly the expression levels of p-PKCε and p-PKA in DRG cells. PGE2 also enhanced proton-evoked action potentials in rat DRG neurons. Finally, peripherally administration of PGE2 dose-dependently exacerbated acid-induced nocifensive behaviors in rats through EP1 and EP4 receptors. Our results indicate that PGE2 enhanced the electrophysiological activity of ASICs in DRG neurons and contributed to acidosis-evoked pain, which revealed a novel peripheral mechanism underlying PGE2 involvement in hyperalgesia by sensitizing ASICs in primary sensory neurons.

TGF-ß1 enhances the activity of acid-sensing ion channel in rat primary sensory neurons.

Transforming growth factor-ß1 (TGF-ß1) is an important member of multifunctional growth factor superfamily. It has been implicated in pain signaling, but little is known about the underlying mechanisms. Herein, we report that TGF-ß1 can exert a sustained enhancing effect on the functional activity of acid-sensing ion channels (ASICs) in rat dorsal root ganglia (DRG) neurons. Pre-application of TGF-ß1 increased the amplitude of proton-gated currents in a dose-dependent manner. Enhancement of ASIC currents lasted for more than 30 min although TGF-ß1 was treated once only. This sustained enhancement by TGF-ß1 could be blocked by extracellular treatment of selective TGF-ß receptor I antagonist SD-208, and abolished by blockade of intracellular several non-Smad-signaling pathways. TGF-ß1 also sustainedly enhanced proton-evoked spikes in rat DRG neurons. Moreover, peripheral pre-treatment with TGF-ß1 dose-dependently exacerbated nociceptive behaviors evoked by intraplantar injection of acetic acid through TGF-ß receptor I in rats. These results suggested that TGF-ß1 potentiated ASIC-mediated electrophysiological activity and nociceptive behaviors, which revealed a novel mechanism underlying TGF-ß1 implicated in peripheral pain signaling by sensitizing ASICs.

The role of nervous system in adaptive response of bone to mechanical loading.

Bone tissue is remodeled through the catabolic function of the osteoclasts and the anabolic function of the osteoblasts. The process of bone homeostasis and metabolism has been identified to be co-ordinated with several local and systemic factors, of which mechanical stimulation acts as an important regulator. Very recent studies have shown a mutual effect between bone and other organs, which means bone influences the activity of other organs and is also influenced by other organs and systems of the body, especially the nervous system. With the discovery of neuropeptide (calcitonin gene-related peptide, vasoactive intestinal peptide, substance P, and neuropeptide Y) and neurotransmitter in bone and the adrenergic receptor observed in osteoclasts and osteoblasts, the function of peripheral nervous system including sympathetic and sensor nerves in bone resorption and its reaction to on osteoclasts and osteoblasts under mechanical stimulus cannot be ignored. Taken together, bone tissue is not only the mechanical transmitter, but as well the receptor of neural system under mechanical loading. This review aims to summarize the relationship among bone, nervous system, and mechanotransduction.

Perspective into the regulation of cell-generated forces toward stem cell migration and differentiation.

Stem cells are promising candidates for cell-based therapies in diverse conditions including regenerating damaged tissues, treating inflammation in virtue of sepsis, acute renal failure, and cardiovascular disease. Advancement of these therapies relies on the ability to guide stem cells to migrate directly and differentiate towards specific cell phenotypes. During the past decade, many researchers have demonstrated that exogenous applied forces could significantly affect the migration and lineage differentiation of stem cells. Besides, recent advances have highlighted the critical role of internal forces due to cell-matrix interaction in the function of stem cells. Stem cells can generate contractile forces to sense the mechanical properties of cell-generated force microenvironment, and thereby perceive mechanical information that directs broad aspects of stem cell functions, including migration and lineage commitment. In the review, we recount the cell-generated force microenvironment of stem cells and discuss the interactions between cell-generated forces with migration and differentiation of stem cells. We also summarize key experimental evidence of a tight linkage between migration and lineage differentiation of stem cells and pose important unanswered questions in this field.

PPAR-α acutely inhibits functional activity of ASICs in rat dorsal root ganglion neurons.

Peroxisome proliferator-activated receptor-α (PPAR-α), a lipid activated transcription factor of nuclear hormone receptor superfamily, can relieve pain through a rapid-response mechanism. However, little is known about the underlying mechanism. Herein, we report that PPAR-α activation acutely inhibits the functional activity of acid-sensing ion channels (ASICs), key sensors for extracellular protons, in rat dorsal root ganglion (DRG) neurons. Pre-application of PPAR-α agonist GW7647 for 2 min decreased the amplitude of proton-gated currents mediated by ASICs in a concentration-dependent manner. GW7647 shifted the concentration-response curve for proton downwards, with a decrease of 36.9 ± 2.3% in the maximal current response to proton. GW7647 inhibition of proton-gated currents can be blocked by GW6471, a selective PPAR-α antagonist. Moreover, PPAR-α activation decreased the number of acidosis-evoked action potentials in rat DRG neurons. Finally, peripheral administration of GW7647 dose-dependently relieved nociceptive responses to injection of acetic acid in rats. These results indicated that activation of peripheral PPAR-α acutely inhibited functional activity of ASICs in a non-genomic manner, which revealed a novel mechanism underlying rapid analgesia through peripheral PPAR-α.

Second generation of familial nonmedullary thyroid carcinoma: A meta-analysis on the clinicopathologic features and prognosis.

Whether the second generation of parent/offspring type familial nonmedullary thyroid carcinoma (FNMTC) is more aggressive and has worse prognosis than their first generation counterpart is controversial. To evaluate the clinicopathologic features and prognosis of the second generation via a comparison between the two groups, We searched three databases (PubMed, EMBASE and the Cochrane library) to review studies published before November 25, 2016. All original studies comparing the clinicopathologic features and prognosis in the first generation of parent/offspring type FNMTC with its second generation counterpart were included. The Q-test and I2 test were used to evaluate homogeneity and funnel plot with Egger's test was used to evaluate publication bias. 6 studies, including 424 subjects were included. There was significant difference between the first and second generation of parent/offspring type FNMTC in the age of onset (SMD = -1.20, 95% CI: -2.38, -0.03, p = 0.045), gender distribution (OR = 0.48, 95% CI: 0.25, 0.90, p = 0.022) and lymph node metastasis (OR = 1.84, 95%CI: 1.16, 2.92, p = 0.01), while no significant difference in other variables. Thus we conclude that the second generation of parent/offspring type FNMTC patients is in higher risk than their first generation counterpart. We believe continuous study is needed to confirm the result.

Evaluating the effectiveness of prophylactic central neck dissection with total thyroidectomy for cN0 papillary thyroid carcinoma: An updated meta-analysis.

BACKGROUND: The effectiveness of prophylactic central neck dissection (pCND) following total thyroidectomy (TT) in patients with clinical node-negative (cN0) papillary thyroid carcinoma (PTC) is still controversial. The aim of this meta-analysis is to evaluate the outcome of pCND and to provide quantitative evidence. METHOD: A detailed literature search of PubMed, EMBASE, ClinicalTrails.gov and Cochrane Library electronic databases for articles published up to October 2016 was carried out. This meta-analysis was performed by the random method (Mantel-Haenszel) model. Locoregional recurrence (LRR) and surgical complications were analyzed. RESULTS: Twenty-two studies comparing pCND + TT (combined) and TT alone in cN0 PTC patients were analyzed. A total of 6930 cases were enrolled, including 2381 cases in the combined group and 4009 cases in the TT-alone group. Compared with TT alone, patients in the combined group showed a significantly lower rate of overall LRR (OR = 0.66, 95% CI = 0.48-0.89) and central compartment recurrence (OR = 0.40, 95% CI = 0.22-0.73). There was no statistical difference in the rate of lateral compartment recurrence. However, the combined group showed a significantly higher rate of temporary and permanent hypoparathyroidism (OR = 2.28, 95% CI = 1.92-2.27/OR = 1.84, 95% CI = 1.15-2.95) and temporary recurrent laryngeal nerve injury (LNR) (OR = 1.53, 95% CI = 1.08-2.16). There was no statistical difference in the rate of permanent LNR, hematoma, hemorrhage or wound infection. CONCLUSIONS: This meta-analysis revealed that pCND with TT was a significantly efficient way to reduce the risk of LRR. However, pCND + TT increased the incidence rate of temporary and permanent hypoparathyroidism and temporary LNR.

Sensitization of ASIC3 by proteinase-activated receptor 2 signaling contributes to acidosis-induced nociception.

BACKGROUND: Tissue acidosis and inflammatory mediators play critical roles in pain. Pro-inflammatory agents trypsin and tryptase cleave and activate proteinase-activated receptor 2 (PAR2) expressed on sensory nerves, which is involved in peripheral mechanisms of inflammation and pain. Extracellular acidosis activates acid-sensing ion channel 3 (ASIC3) to trigger pain sensation. Here, we show that a functional interaction of PAR2 and ASIC3 could contribute to acidosis-induced nociception. METHODS: Electrophysiological experiments were performed on both rat DRG neurons and Chinese hamster ovary (CHO) cells expressing ASIC3 and PAR2. Nociceptive behavior was induced by acetic acid in rats. RESULTS: PAR2-AP, PAR2-activating peptide, concentration-dependently increased the ASIC3 currents in CHO cells transfected with ASIC3 and PAR2. The proton concentration-response relationship was not changed, but that the maximal response increased 58.7 ± 3.8% after pretreatment of PAR2-AP. PAR2 mediated the potentiation of ASIC3 currents via an intracellular cascade. PAR2-AP potentiation of ASIC3 currents disappeared after inhibition of intracellular G protein, PLC, PKC, or PKA signaling. Moreover, PAR2 activation increased proton-evoked currents and spikes mediated by ASIC3 in rat dorsal root ganglion neurons. Finally, peripheral administration of PAR2-AP dose-dependently exacerbated acidosis-induced nocifensive behaviors in rats. CONCLUSIONS: These results indicated that PAR2 signaling sensitized ASIC3, which may contribute to acidosis-induced nociception. These represent a novel peripheral mechanism underlying PAR2 involvement in hyperalgesia by sensitizing ASIC3 in primary sensory neurons.

Preoperative ultrasound-guided carbon nanoparticles localization for metastatic lymph nodes in papillary thyroid carcinoma during reoperation: A retrospective cohort study.

Due to the damaged anatomical structure and a large amount of fibrous and scar tissues in the surgical field, reoperation of papillary thyroid carcinoma is difficult. This study introduces a new method of locating metastatic lymph nodes during reoperation and evaluates the effectiveness and safety of the preoperative ultrasound-guided carbon nanoparticles (CNs) localization. This retrospective cohort study enrolled 52 patients who were diagnosed with lymph node metastasis by histopathology and underwent reoperation from October 2015 to February 2016. The modified radical neck dissection or selective neck node dissection was performed. A total of 26 patients underwent preoperative ultrasound-guided CNs injection, and other 26 patients did not. Tolerance, the result of injection, the number of resected metastatic lymph nodes, and postoperative complications were recorded and analyzed. In CNs group, 102 suspicious nonpalpable lesions in 26 patients were injected with CNs, and 99 of the 102 lesions were successfully identified by surgeon in the reoperation. The positive rate of resected lymph nodes in total, in the central compartment, and in the lateral compartment were 31.6%, 31.2%, and 32.8%, respectively, which was significantly higher than that in the control group (P < 0.001, P < 0.001, and P = 0.041). In addition, the positive rates of levels III, IV, and V in the CNs group were 35.6%, 21.9%, and 30.5%, respectively, which was significantly higher than that in the control group (P < 0.001, P = 0.005, and P = 0.01). In additional, in the CNs group, the rate of temporary hypoparathyroidism was significantly lower compared with the control group (0% vs 26.9%, P = 0.021). Preoperative ultrasound-guided CNs injection is a safe and effective method for localization of the metastatic lymph nodes during reoperation.