Optogenetic fMRI for Brain-Wide Circuit Analysis of Sensory Processing.

Sensory processing is a complex neurological process that receives, integrates, and responds to information from one's own body and environment, which is closely related to survival as well as neurological disorders. Brain-wide networks of sensory processing are difficult to investigate due to their dynamic regulation by multiple brain circuits. Optogenetics, a neuromodulation technique that uses light-sensitive proteins, can be combined with functional magnetic resonance imaging (ofMRI) to measure whole-brain activity. Since ofMRI has increasingly been used for investigating brain circuits underlying sensory processing for over a decade, we systematically reviewed recent ofMRI studies of sensory circuits and discussed the challenges of optogenetic fMRI in rodents.

A Systems Biology Approach to Investigating the Interaction between Serotonin Synthesis by Tryptophan Hydroxylase and the Metabolic Homeostasis.

Obesity has become a global public health and economic problem. Obesity is a major risk factor for a number of complications, such as type 2 diabetes, cardiovascular disease, fatty liver disease, and cancer. Serotonin (5-hydroxytryptamine [5-HT]) is a biogenic monoamine that plays various roles in metabolic homeostasis. It is well known that central 5-HT regulates appetite and mood. Several 5-HT receptor agonists and selective serotonin receptor uptake inhibitors (SSRIs) have shown beneficial effects on appetite and mood control in clinics. Although several genetic polymorphisms related to 5-HT synthesis and its receptors are strongly associated with obesity, there is little evidence of the role of peripheral 5-HT in human metabolism. In this study, we performed a systemic analysis of transcriptome data from the Genotype-Tissue Expression (GTEX) database. We investigated the expression of 5-HT and tryptophan hydroxylase (TPH), the rate-limiting enzyme of 5-HT biosynthesis, in the human brain and peripheral tissues. We also performed differential gene expression analysis and predicted changes in metabolites by comparing gene expressions of tissues with high TPH expression to the gene expressions of tissues with low TPH expression. Our analyses provide strong evidence that serotonin plays an important role in the regulation of metabolic homeostasis in humans.

Involvement of cannabinoid type 1 receptor in fasting-induced analgesia.

The endocannabinoid system (ECS) is known to modulate not only food intake but also pain, especially via the cannabinoid type 1 receptor (CB1R) expressed throughout the central nervous system and the peripheral tissues. Our previous study demonstrated that fasting produces an analgesic effect in adult male mice, which is reversed by intraperitoneal (i.p.) administration of CB1R antagonist (SR 141716). In the present study, we further examined the effect of CB1R expressed in the peripheral tissues. In the formalin-induced inflammatory pain model, i.p. administration of peripherally restricted CB1R antagonist (AM 6545) reversed fasting-induced analgesia. However, intraplantar administration of SR 141716 did not affect fasting-induced analgesia. Furthermore, mRNA expression of CB1R did not change in the formalin model by fasting in the dorsal root ganglia. The formalin-induced c-Fos expression at the spinal cord level was not affected by fasting, and in vivo recording from the superficial dorsal horn of the lumbar spinal cord revealed that fasting did not affect formalin-induced neural activity, which indicates minimal involvement of the spinal cord in fasting-induced analgesia. Finally, when we performed subdiaphragmatic vagotomy to block the hunger signal from the gastrointestinal (GI) system, AM 6545 did not affect fasting-induced analgesia, but SR 141716 still reversed fasting-induced analgesia. Taken together, our results suggest that both peripheral and central CB1Rs contribute to fasting-induced analgesic effects and the CB1Rs in the GI system which transmit fasting signals to the brain, rather than those in the peripheral sensory neurons, may contribute to fasting-induced analgesic effects.

Design of Dual-Mode Local Oscillators Using CMOS Technology for Motion Detection Sensors.

Recently, studies have been actively carried out to implement motion detecting sensors by applying radar techniques. Doppler radar or frequency-modulated continuous wave (FMCW) radar are mainly used, but each type has drawbacks. In Doppler radar, no signal is detected when the movement is stopped. Also, FMCW radar cannot function when the detection object is near the sensor. Therefore, by implementing a single continuous wave (CW) radar for operating in dual-mode, the disadvantages in each mode can be compensated for. In this paper, a dual mode local oscillator (LO) is proposed that makes a CW radar operate as a Doppler or FMCW radar. To make the dual-mode LO, a method that controls the division ratio of the phase locked loop (PLL) is used. To support both radar mode easily, the proposed LO is implemented by adding a frequency sweep generator (FSG) block to a fractional-N PLL. The operation mode of the LO is determined by according to whether this block is operating or not. Since most radar sensors are used in conjunction with microcontroller units (MCUs), the proposed architecture is capable of dual-mode operation by changing only the input control code. In addition, all components such as VCO, LDO, and loop filter are integrated into the chip, so complexity and interface issues can be solved when implementing radar sensors. Thus, the proposed dual-mode LO is suitable as a radar sensor.

The incidence of osteoarthritic change on computed tomography of Korean temporomandibular disorder patients diagnosed by RDC/TMD; a retrospective study.

Objective Osteoarthritis (OA) of the temporomandibular joint (TMJ) is generally thought to be an age-related disease like those of other joints. This study aims to investigate the incidence of computed tomographic (CT) OA changes in Korean temporomandibular disorder (TMD) patients diagnosed by the Research Diagnostic Criteria for TMD (RDC/TMD). Materials and methods The clinical records and radiographs of 1038 TMD patients (297 men and 741 women with mean age 31.1 ± 17.4 and 34.0 ± 16.2, respectively) diagnosed based on RDC/TMD Axis I in 2010 were reviewed. Results The incidence rate of OA changes in TMD patients is estimated to 27.3%, and higher in women than in men (15.5% in men and 32.0% in women) by 2.3 odds (p < 0.001). It has no correlation with age, showing an almost flat incidence rate throughout the age from the 2nd decade and has no correlation as well with pain or disc displacement diagnosed according to RDC/TMD, while arthrosis/arthritis diagnosis based on RDC/TMD supplemented by plain radiographs shows high risk of OA changes on CT by 38.8 odds (p < 0.05). Conclusions These results imply that the OA changes in young Korean TMD patients are as common as in the old and have no correlation with clinical pain and noise. Considered with high prevalence of TMDs known in the young population, the overall/absolute OA changes in the TMJ can be even higher in the young than in the old population, not like in other joints.

Direct effect of chlorine dioxide, zinc chloride and chlorhexidine solution on the gaseous volatile sulfur compounds.

OBJECTIVE: This study focused on the ability of aqueous anti-volatile-sulfur-compound (VSC) solutions to eliminate gaseous VSCs by direct contact in a sealed space to describe possible mode of action of anti-VSC agents. MATERIALS AND METHODS: Twenty milliliters of each experimental solution, 0.16% sodium chlorite, 0.25% zinc chloride, 0.1% chlorhexidine and distilled water, was injected into a Teflon bag containing mixed VSCs, hydrogen sulfide, methyl mercaptan and dimethyl sulfide and mixed vigorously for 30 s. The VSC concentration was measured by gas chromatography before, immediately after, 30 min and 60 min after mixing. RESULTS: The sodium chlorite solution reduced the VSC concentration remarkably. After mixing, nearly all VSCs were eliminated immediately and no VSCs were detected at 30 and 60 min post-mixing. However, in the other solutions, the VSC concentration decreased by ∼30% immediately after mixing and there was no further decrease. CONCLUSION: The results suggest that sodium chlorite solution has the effect of eliminating gaseous VSCs directly. This must be because it can release chlorine dioxide gas which can react directly with gaseous VSCs. In the case of other solutions that have been proved to be effective to reduce halitosis clinically, it can be proposed that their anti-VSC effect is less likely due to the direct chemical elimination of gaseous VSCs in the mouth.

Effect of Tannic Acid Concentrations on Temperature-Sensitive Sol-Gel Transition and Stability of Tannic Acid/Pluronic F127 Composite Hydrogels.

Recently, interest in polyphenol-containing composite adhesives for various biomedical applications has been growing. Tannic acid (TA) is a polyphenolic compound with advantageous properties, including antioxidant and antimicrobial properties. Additionally, TA contains multiple hydroxyl groups that exhibit biological activity by forming hydrogen bonds with proteins and biomacromolecules. Furthermore, TA-containing polymer composites exhibit excellent tissue adhesion properties. In this study, the gelation behavior and adhesion forces of TA/Pluronic F127 (TA/PluF) composite hydrogels were investigated by varying the TA and PluF concentrations. PluF (above 16 wt%) alone showed temperature-responsive gelation behavior because of the closely packed micelle aggregates. After the addition of a small amount of TA, the TA/PluF hydrogels showed thermosensitive behavior similar to that of PluF hydrogels. However, the TA/PluF hydrogels containing more than 10 wt% TA completely suppressed the thermo-responsive gelation kinetics of PluF, which may have been due to the hydrogen bonds between TA and PluF. In addition, TA/PluF hydrogels with 40 wt% TA showed excellent tissue adhesion properties and bursting pressure in porcine intestinal tissues. These results are expected to aid in understanding the use of mixtures of TA and thermosensitive block copolymers to fabricate adhesive hydrogels for versatile biomedical applications.

Clinical features and molecular genetics associated with brain metastasis in suspected early-stage non-small cell lung cancer.

Introduction: Regarding whether brain magnetic resonance imaging (MRI) should be routine in patients with suspected early-stage lung cancer, guideline recommendations are inconsistent. Therefore, we performed this study to evaluate the incidence of and risk factors for brain metastasis (BM) in patients with suspected early-stage non-small-cell lung cancer (NSCLC). Methods: A review of the medical charts of consecutive NSCLC patients diagnosed between January 2006 and May 2020 was performed. We identified 1,382 NSCLC patients with clinical staging of T1/2aN0M0 (excluding BM), and investigated the incidence, clinical predictors, and prognosis of BM in the cohort. We also performed RNA-sequencing differential expression analysis using transcriptome of 8 patients, using DESeq2 package (version 1.32.0) with R (version 4.1.0). Results: Among 1,382 patients, nine hundred forty-nine patients (68.7%) underwent brain MRI during staging, and 34 patients (3.6%) were shown to have BM. Firth's bias-reduced logistic regression showed that tumor size (OR 1.056; 95% CI 1.009-1.106, p=0.018) was the only predictor of BM, and pathologic type was not a predictor of BM in our cohort (p>0.05). The median overall survival for patients with brain metastasis was 5.5 years, which is better than previously reported in the literature. RNA-sequencing differential expression analysis revealed the top 10 significantly upregulated genes and top 10 significantly downregulated genes. Among the genes involved in BM, Unc-79 homolog, non-selective sodium leak channel (NALCN) channel complex subunit (UNC79) was the most highly expressed gene in the lung adenocarcinoma tissues from the BM group, and an in vitro assay using A549 cells revealed that the NALCN inhibitor suppressed lung cancer cell proliferation and migration. Conclusions: Given the incidence and favorable outcome of BM in patients with suspected early-stage NSCLC, selective screening with brain MRI may be considered, especially in patients with high-risk features.

Role of anterior cingulate cortex inputs to periaqueductal gray for pain avoidance.

Although pain-related excessive fear is known to be a key factor in chronic pain disability, which involves the anterior cingulate cortex (ACC), little is known about the downstream circuits of the ACC for fear avoidance in pain processing. Using behavioral experiments and functional magnetic resonance imaging with optogenetics at 15.2 T, we demonstrate that the ACC is a part of the abnormal circuit changes in chronic pain and its downstream circuits are closely related to modulating sensorimotor integration and generating active movement rather than carrying sensory information. The projection from the ACC to the dorsolateral and lateral parts of the periaqueductal gray (dl/lPAG) especially enhances both reflexive and active avoidance behavior toward pain. Collectively, our results indicate that increased signals from the ACC to the dl/lPAG might be critical for excessive fear avoidance in chronic pain disability.

Protocol for mouse optogenetic fMRI at ultrahigh magnetic fields.

Mouse optogenetic functional magnetic resonance imaging (opto-fMRI) is critical for linking genes and functions and for mapping cell-type-specific neural circuits in the whole brain. Herein, we describe how opto-fMRI images can be reliably obtained in anesthetized mice with minimal distortions at ultrahigh magnetic fields. The protocol includes surgical and anesthesia procedures, animal cradle modification, animal preparation and setup, animal physiology maintenance, and pilot fMRI scanning. This protocol will enable reproducible mouse opto-fMRI experiments. For complete details on the use and execution of this protocol, please refer to Jung et al. (2021),1 Jung et al. (2022),2 and Moon et al. (2021).3.

Artificial intelligence in detecting temporomandibular joint osteoarthritis on orthopantomogram.

Orthopantomogram (OPG) is important for primary diagnosis of temporomandibular joint osteoarthritis (TMJOA), because of cost and the radiation associated with computed tomograms (CT). The aims of this study were to develop an artificial intelligence (AI) model and compare its TMJOA diagnostic performance from OPGs with that of an oromaxillofacial radiology (OMFR) expert. An AI model was developed using Karas' ResNet model and trained to classify images into three categories: normal, indeterminate OA, and OA. This study included 1189 OPG images confirmed by cone-beam CT and evaluated the results by model (accuracy, precision, recall, and F1 score) and diagnostic performance (accuracy, sensitivity, and specificity). The model performance was unsatisfying when AI was developed with 3 categories. After the indeterminate OA images were reclassified as normal, OA, or omission, the AI diagnosed TMJOA in a similar manner to an expert and was in most accord with CBCT when the indeterminate OA category was omitted (accuracy: 0.78, sensitivity: 0.73, and specificity: 0.82). Our deep learning model showed a sensitivity equivalent to that of an expert, with a better balance between sensitivity and specificity, which implies that AI can play an important role in primary diagnosis of TMJOA from OPGs in most general practice clinics where OMFR experts or CT are not available.

Influence of bolus size and chewing side on temporomandibular joint intra-articular space during mastication.

Previous studies suggested that, during mastication, magnitude and location of mechanical load in the temporomandibular joint (TMJ) might depend on chewing side and bolus size. Aim of this study was to dynamically measure the TMJ space while chewing on standardized boluses to assess the relationship among minimum intra-articular distances (MID), their location on the condylar surface, bolus size, and chewing side. Mandibular movements of 12 participants (6f, 24±1y.o.; 6 m, 28±6y.o.) were tracked optoelectronically while chewing unilaterally on rubber boluses of 15 × 15 × 5, 15 × 15 × 10, and 15 × 15 × 15 mm3 size. MID and their location along the main condylar axis were determined with dynamic stereometry. MID were normalized on the intra-articular distance in centric occlusion. Repeated measures ANOVA (α = 0.05) showed that MID were smaller on the balancing (0.74±0.19) than on the working condyle (0.89±0.16) independently of bolus size (p < 0.0001). MIDs did not differ between 5 and 10 mm bolus thicknesses (0.80±0.17) but increased for 15 mm (0.85±0.22, p = 0.024) and were located mostly laterally, close to the condylar center. This study confirmed higher reduction of TMJ space on the balancing than on the working condyle during mastication. Intra-articular distances increased significantly for the greatest bolus thickness. Loaded areas were located laterally, for both working and balancing joint.

Long-term Changes of Temporomandibular Joint Osteoarthritis on Computed Tomography.

This study aimed to understand long-term changes of the osteoarthritic temporomandibular joint (TMJ) condyle using computed tomography (CT) and to verify its correlation with clinical characteristics of temporomandibular disorders. Eighty-nine patients (152 joints; 76 female, 13 male) who had taken follow-up CTs (mean follow-up period: 644.58 ± 325.71 days) at least once in addition to their initial evaluation were selected. Cross-sectional demographic and clinical data and longitudinal CT images were collected. Data were analyzed by analysis of variance and logistic regression. Overall destructive change index (number of TMJ condyle sections in which destructive change was observed) decreased from 1.56 to 0.66. Improvement was seen in 93 joints (61.2%) and 27 joints (17.8%) worsened. In the pain positive group, both initial and final destructive change index were significantly higher compared to the pain negative group (p = 0.04). Occlusal stabilization splint therapy and nonsteroidal anti-inflammatory drug administration showed a significant effect on improving the prognosis of TMJ osteoarthritis (p = 0.015 and 0.011). In conclusion, TMJ osteoarthritis showed long-term improvement in the majority of cases. TMJ osteoarthritis accompanied by pain showed unfavorable prognosis with additional bone destruction. Occlusal stabilization splint and nonsteroidal anti-inflammatory drug administration were beneficial on the prognosis of TMJ osteoarthritis.

A new organoleptic testing method for evaluating halitosis.

BACKGROUND: Halitosis is a common condition in the adult population. The organoleptic method has been used widely in the clinical field for the diagnosis of halitosis because of its simplicity; however, this method has limitations as a result of its lack of objectivity and reproducibility. We developed a new method of organoleptic testing using a gastight syringe to overcome these limitations. The purpose of this study was to investigate the clinical usefulness of this new method by analyzing the correlations between the organoleptic score measured by it and data from the portable sulfide monitor and gas chromatography in the same subjects. METHODS: Fifty-two subjects (20 males and 32 females; mean age, 35.6 +/- 12.8) who visited the Halitosis Clinic at Seoul National University Dental Hospital, were recruited. We recorded the organoleptic score and measured the concentration of volatile sulfur compounds (VSCs) using a portable sulfide monitor and gas chromatography. The organoleptic test was performed in a standardized way using a gastight syringe and a paper cup connected to a plastic straw. RESULTS: The organoleptic score by the new method showed a significant positive correlation with the total VSC concentrations that were measured by gas chromatography (r = 0.790; P <0.01) and with the portable sulfide monitor (r = 0.822; P <0.01). There were significant positive correlations between the organoleptic score obtained by the new method and the concentration of H(2)S (r = 0.776; P <0.01), CH(3)SH (r = 0.715; P <0.01), and (CH(3))(2)S (r = 0.674; P <0.01) measured by gas chromatography. CONCLUSION: The new organoleptic test is a valuable tool for measuring halitosis in the clinical field.

Hedonic drinking engages a supraspinal inhibition of thermal nociception in adult rats.

The taste of sucrose is commonly used to provide pain relief in newborn humans and is innately analgesic to neonatal rodents. In adulthood, sucrose remains a strong motivator to feed, even in potentially hazardous circumstances (ie, threat of tissue damage). However, the neurobiological mechanisms of this endogenous reward-pain interaction are unclear. We have developed a simple model of sucrose drinking-induced analgesia in Sprague-Dawley rats (6-10 weeks old) and have undertaken a behavioral and pharmacological characterization using the Hargreaves' test of hind-paw thermal sensitivity. Our results reveal an acute, potent, and robust inhibitory effect of sucrose drinking on thermal nociceptive behaviour that unlike the phenomenon in neonates is independent of endogenous opioid signalling and does not seem to operate through classical descending inhibition of the spinal cord circuitry. Experience of sucrose drinking had a conditioning effect whereby the apparent expectancy of sucrose enabled water alone (in euvolemic animals) to elicit a short-lasting placebo-like analgesia. Sweet taste alone, however, was insufficient to elicit analgesia in adult rats intraorally perfused with sucrose. Instead, the sucrose analgesia phenomenon only appeared after conditioning by oral perfusion in chronically cannulated animals. This sucrose analgesia was completely prevented by systemic dosing of the endocannabinoid CB1 receptor antagonist rimonabant. These results indicate the presence of an endogenous supraspinal analgesic circuit that is recruited by the context of rewarding drinking and is dependent on endocannabinoid signalling. We propose that this hedonic sucrose-drinking model may be useful for further investigation of the supraspinal control of pain by appetite and reward.

The analgesic effect of refeeding on acute and chronic inflammatory pain.

Pain is susceptible to various cognitive factors. Suppression of pain by hunger is well known, but the effect of food intake after fasting (i.e. refeeding) on pain remains unknown. In the present study, we examined whether inflammatory pain behavior is affected by 24 h fasting and 2 h refeeding. In formalin-induced acute inflammatory pain model, fasting suppressed pain behavior only in the second phase and the analgesic effect was also observed after refeeding. Furthermore, in Complete Freund's adjuvant-induced chronic inflammatory pain model, both fasting and refeeding reduced spontaneous pain response. Refeeding with non-calorie agar produced an analgesic effect. Besides, intraperitoneal (i.p.) administration of glucose after fasting, which mimics calorie recovery following refeeding, induced analgesic effect. Administration of opioid receptor antagonist (naloxone, i.p.) and cannabinoid receptor antagonist (SR 141716, i.p.) reversed fasting-induced analgesia, but did not affect refeeding-induced analgesia in acute inflammatory pain model. Taken together, our results show that refeeding produce analgesia in inflammatory pain condition, which is associated with eating behavior and calorie recovery effect.

alpha-Galactosidase activity in human saliva.

OBJECTIVE: The purpose of this study was to investigate whether alpha-galactosidase activity is present in whole and glandular saliva and whether alpha-galactosidase activity depends on blood type and secretor status. DESIGN: For the first experiments, 30 healthy participants (15 men, 15 women; mean age, 24.2+/-1.5 years) who were 10 A, 10 B, and 10 O blood type subjects were included. alpha-Galactosidase activity in unstimulated whole saliva (UWS) was assayed by using 4-methylumbelliferyl-alpha-d-galactopyranoside as a substrate. Total protein concentration was determined by bicinchoninic acid assay. The secretor status of the blood group antigens was determined by immunoblotting. alpha-Galactosidase activity in UWS according to gender, blood type, secretor status, sample clarification, and buffer was investigated. Daily variations of alpha-galactosidase activity and alpha-galactosidase isozyme activity were also investigated. For the second experiments, 10 healthy blood type B participants (5 men, 5 women; mean age, 27.0+/-2.7 years) were enrolled. alpha-Galactosidase activity in whole and glandular saliva was investigated. RESULTS: alpha-Galactosidase activity was detected in UWS and was mainly isozyme A activity. There was no difference in alpha-galactosidase activity according to gender, blood type, and secretor status. alpha-Galactosidase activity in UWS was higher in unclarified samples than in clarified ones and showed wide daily variations. alpha-Galactosidase activity in whole saliva was significantly higher than that in glandular saliva. CONCLUSIONS: alpha-Galactosidase activity which is mainly isozyme A activity was detected in human whole and glandular saliva. alpha-Galactosidase activity in UWS did not differ according to blood type and secretor status.

Pharmacopuncture With Scolopendra subspinipes Suppresses Mechanical Allodynia in Oxaliplatin-Induced Neuropathic Mice and Potentiates Clonidine-induced Anti-allodynia Without Hypotension or Motor Impairment.

Chemotherapy-induced neuropathic pain is a common dose-limiting side effect of anticancerdrugs but lacks an effective treatment strategy. Scolopendra subspinipes has been used in traditional medicine to treat chronic neuronal diseases. Moreover, pharmacopuncture with S subspinipes (SSP) produces potent analgesia in humans and experimental animals. In this study, we examined the effect of SSP into the ST36 acupoint on oxaliplatin-induced mechanical allodynia in mice. Acupoint treatment with SSP (0.5%/20 µL) significantly decreased mechanical allodynia produced by a single oxaliplatin injection (10mg/kg i.p.), which was completely prevented by acupoint preinjection of lidocaine. Intrathecal treatment with yohimbine (25 µg/5 µL), an α2-adrenoceptor antagonist, prevented the anti-allodynic effect of SSP. In contrast, a high dose (0.1mg/kg i.p.) ofclonidine,an α2-adrenoceptor agonist, suppressed oxaliplatin-induced mechanical allodynia butproduced severe side effects including hypotension, bradycardia, and motor impairment. The combination of SSP with a lower dose of clonidine (0.03 mg/kg) produced a comparable analgesic effect without side effects. Collectively, our findings demonstrate that SSP produces an analgesic effect in oxaliplatin-induced pain via neuronal conduction at the acupoint and activation of spinal α2-adrenoceptors. Moreover, acombination of low-dose clonidine with SSP represents a novel and safe therapeutic strategy for chemotherapy-induced chronic pain. PERSPECTIVE: SSP can relieve oxaliplatin-induced mechanical allodynia. Moreover, SSP potentiates clonidine-induced anti-allodynia, allowing a lower dose of clonidine with no significant side effects. The combination of SSP and low-dose clonidine might provide a novel strategy for the management of chemotherapy-induced peripheral neuropathy.

Age estimation of Korean adults by occlusal tooth wear.

The aim of the present study was to evaluate the validity of the modified Kim's scoring system as a practical method of recording occlusal tooth wear and estimating age. For this purpose, 1092 pairs of maxillary and mandibular full-arch casts were randomly selected, scored, and analyzed. The results showed that the modified Kim's scoring system had excellent reliability, and that occlusal tooth wear had a positive correlation with age. Tooth wear scores of all teeth except the two lower central incisors were higher in males than in females. Calculating tables for age estimation were designed by multiple linear regression analysis. Estimated ages were within +/-5 years of actual ages in 63.5% of male subjects, and 64.0% of female subjects. The accuracy of age estimation was increased when the subjects were divided into two age groups and data were re-analyzed. Collectively, it was shown that the modified Kim's scoring system is a reliable and accurate method for age estimation, and that the data from these 1092 individuals can be used as a standard for age estimation of Korean adults.

Sinomenine produces peripheral analgesic effects via inhibition of voltage-gated sodium currents.

Sinomenium acutum has been used in traditional medicine to treat a painful disease such as rheumatic arthritis and neuralgia. Sinomenine, which is a main bioactive ingredient in Sinomenium acutum, has been reported to have an analgesic effect in diverse pain animal models. However little is known about the detailed mechanisms underlying peripheral analgesic effect of sinomenine. In the present study, we aimed to elucidate its cellular mechanism by using formalin-induced acute inflammatory pain model in mice. We found that intraperitoneal (i.p.) administration of sinomenine (50mg/kg) suppressed formalin-induced paw licking behavior in both the first and the second phase. Formalin-induced c-Fos protein expression was also suppressed by sinomenine (50mg/kg i.p.) in the superficial dorsal horn of spinal cord. Whole-cell patch-clamp recordings from small-sized dorsal root ganglion (DRG) neurons revealed that sinomenine reversibly increased the spike threshold and the threshold current intensity for evoking a single spike and decreased firing frequency of action potentials evoked in response to a long current pulse. Voltage-gated sodium currents (INa) were also significantly reduced by sinomenine in a dose-dependent manner (IC50=2.3±0.2mM). Finally, we confirmed that intraplantar application of sinomenine suppressed formalin-induced pain behavior only in the first phase, but not the second phase. Taken together, our results suggest that sinomenine has a peripheral analgesic effect by inhibiting INa.