Age-Related Characteristics of Resting-State Electroencephalographic Signals and the Corresponding Analytic Approaches: A Review.

The study of the effects of aging on neural activity in the human brain has attracted considerable attention in neurophysiological, neuropsychiatric, and neurocognitive research, as it is directly linked to an understanding of the neural mechanisms underlying the disruption of the brain structures and functions that lead to age-related pathological disorders. Electroencephalographic (EEG) signals recorded during resting-state conditions have been widely used because of the significant advantage of non-invasive signal acquisition with higher temporal resolution. These advantages include the capability of a variety of linear and nonlinear signal analyses and state-of-the-art machine-learning and deep-learning techniques. Advances in artificial intelligence (AI) can not only reveal the neural mechanisms underlying aging but also enable the assessment of brain age reliably by means of the age-related characteristics of EEG signals. This paper reviews the literature on the age-related features, available analytic methods, large-scale resting-state EEG databases, interpretations of the resulting findings, and recent advances in age-related AI models.

Ketonuria as an Indicator of Improvement of Renal Function in Patients with Type 2 Diabetes Receiving SGLT2 Inhibitor Treatment.

We investigated the potential association between ketonuria during treatment with sodium-glucose cotransporter-2 (SGLT2) inhibitors and its renoprotective effect in patients with type 2 diabetes. We included 192 patients who had received SGLT2 inhibitors for more than 6 months. After propensity score matching, 52 patients each were allocated into groups with or without ketonuria, respectively. The estimated glomerular filtration rate exhibited a significant improvement only in subjects with ketonuria (without ketonuria: mean difference, -0.02 mL/min/1.73 m2 [95% confidence interval (CI), -3.87 to 3.83 mL/min/1.73 m2] vs. with ketonuria: mean difference, 6.81 mL/min/1.73 m2 [95% CI, 3.16 to 10.46 mL/min/1.73 m2]; P<0.001). Improvement in estimated glomerular filtration rate at 6 months was associated with female sex and lower baseline body weight, blood pressure, and triglyceride levels in patients with ketonuria. In conclusion, the presence of ketonuria was associated with the renoprotective effect of SGLT2 inhibitors, and female sex and the absence of metabolic syndrome components may serve as additional indicators of these medications' substantial renoprotective effects in individuals with ketonuria.

Mortality in patients with chronic hepatitis B treated with tenofovir or entecavir: A multinational study.

BACKGROUND AND AIM: The benefits of entecavir (ETV) versus tenofovir disoproxil fumarate (TDF) in reducing the development of chronic hepatitis B (CHB)-related hepatocellular carcinoma remain controversial. Whether mortality rates differ between patients with CHB treated with ETV and those treated with TDF is unclear. METHODS: A total of 2542 patients with CHB treated with either ETV or TDF were recruited from a multinational cohort. A 1:1 propensity score matching was performed to balance the differences in baseline characteristics between the two patient groups. We aimed to compare the all-cause, liver-related, and non-liver-related mortality between patients receiving ETV and those receiving TDF. RESULTS: The annual incidence of all-cause mortality in the entire cohort was 1.0/100 person-years (follow-up, 15 757.5 person-years). Patients who received TDF were younger and had a higher body mass index, platelet count, hepatitis B virus deoxyribonucleic acid levels, and proportion of hepatitis B e-antigen seropositivity than those who received ETV. The factors associated with all-cause mortality were fibrosis-4 index > 6.5 (hazard ratio [HR]/confidence interval [CI]: 3.13/2.15-4.54, P < 0.001), age per year increase (HR/CI: 1.05/1.04-1.07, P < 0.001), alanine aminotransferase level per U/L increase (HR/CI: 0.997/0.996-0.999, P = 0.003), and γ-glutamyl transferase level per U/L increase (HR/CI: 1.002/1.001-1.003, P < 0.001). No significant difference in all-cause mortality was observed between the ETV and TDF groups (log-rank test, P = 0.69). After propensity score matching, no significant differences in all-cause, liver-related, or non-liver-related mortality were observed between the two groups. CONCLUSIONS: Long-term outcomes of all-cause mortality and liver-related and non-liver-related mortality did not differ between patients treated with ETV and those receiving TDF.

Deep electroacupuncture of neurogenic spots attenuates immobilization stress-induced acute hypertension in rats.

Background: Our previous studies proved that neurogenic inflammatory spots (or neurogenic spots) have the same physiological features as acupuncture points and that neurogenic spot stimulation generates therapeutic effects in various animal models. However, it is unclear how deeply the neurogenic spots should be stimulated to generate therapeutic effects. Methods: The effects of acupuncture at various needle depths below the neurogenic spot were examined in a rat immobilization stress-induced hypertension (IMH) model. Electroacupuncture was applied to a neurogenic spot at depths of 1, 2, or 3 mm using a concentric bipolar electrode. Results: Electrical stimulation of the neurogenic spot at a 3-mm depth most effectively lowered blood pressure compared with controls and stimulation at 1- and 2-mm depths, which was inhibited by pretreatment with a local anesthetic lidocaine. Electrical stimulation of the neurogenic spot or injection of substance P (SP) at a 3-mm depth significantly excited the rostral ventrolateral medulla (rVLM) compared with superficial stimulation. Electrical stimulation applied at a 3-mm depth on neurogenic spots dominantly caused c-fos expression from rVLM and ventrolateral periaqueductal gray (vlPAG) in IMH rats. Pretreatment with resiniferatoxin (RTX) injection into the neurogenic spot to ablate SP or calcitonin gene-related peptide (CGRP) prevented the effects of 3-mm neurogenic spot stimulation on blood pressure in IMH rats. Conversely, artificial injection of SP or CGRP generated anti-hypertensive effects in IMH rats. Conclusion: Our data suggest that neurogenic spot stimulation at a 3-mm depth generated anti-hypertensive effects through the local release of SP and CGRP and activation of rVLM and vlPAG.

Impact of Antidiabetic Drugs on Clinical Outcomes of COVID-19: A Nationwide Population-Based Study.

BACKGRUOUND: Inconsistent results have been reported regarding the association between the use of antidiabetic drugs and the clinical outcomes of coronavirus disease 2019 (COVID-19). This study aimed to investigate the effect of antidiabetic drugs on COVID-19 outcomes in patients with diabetes using data from the National Health Insurance Service (NHIS) in South Korea. METHODS: We analyzed the NHIS data of patients aged ≥20 years who tested positive for COVID-19 and were taking antidiabetic drugs between December 2019 and June 2020. Multiple logistic regression analysis was performed to analyze the clinical outcomes of COVID-19 based on the use of antidiabetic drugs. RESULTS: A total of 556 patients taking antidiabetic drugs tested positive for COVID-19, including 271 male (48.7%), most of whom were in their sixties. Of all patients, 433 (77.9%) were hospitalized, 119 (21.4%) received oxygen treatment, 87 (15.6%) were admitted to the intensive care unit, 31 (5.6%) required mechanical ventilation, and 61 (11.0%) died. Metformin was significantly associated with the lower risks of mechanical ventilation (odds ratio [OR], 0.281; 95% confidence interval [CI], 0.109 to 0.720; P=0.008), and death (OR, 0.395; 95% CI, 0.182 to 0.854; P=0.018). Dipeptidylpeptidase-4 inhibitor (DPP-4i) were significantly associated with the lower risks of oxygen treatment (OR, 0.565; 95% CI, 0.356 to 0.895; P=0.015) and death (OR, 0.454; 95% CI, 0.217 to 0.949; P=0.036). Sulfonylurea was significantly associated with the higher risk of mechanical ventilation (OR, 2.579; 95% CI, 1.004 to 6.626; P=0.049). CONCLUSION: In patients with diabetes and COVID-19, metformin exhibited reduced risks of mechanical ventilation and death, DPP- 4i was linked with lower risks of oxygen treatment and death, while sulfonylurea was related to the increased risk of mechanical ventilation.

Pretreatment gamma-glutamyl transferase predicts mortality in patients with chronic hepatitis B treated with nucleotide/nucleoside analogs.

Elevated serum gamma-glutamyl transferase (GGT) levels are associated with chronic hepatitis B (CHB)-related hepatocellular carcinoma. However, their role in predicting mortality in patients with CHB treated with nucleotide/nucleoside analogs (NAs) remains elusive. Altogether, 2843 patients with CHB treated with NAs were recruited from a multinational cohort. Serum GGT levels before and 6 months (Month-6) after initiating NAs were measured to explore their association with all-cause, liver-related, and non-liver-related mortality. The annual incidence of all-cause mortality was 0.9/100 person-years over a follow-up period of 17,436.3 person-years. Compared with patients who survived, those who died had a significantly higher pretreatment (89.3 vs. 67.4 U/L, p = 0.002) and Month-6-GGT levels (62.1 vs. 38.4 U/L, p < 0.001). The factors associated with all-cause mortality included cirrhosis (hazard ratio [HR]/95% confidence interval [CI]: 2.66/1.92-3.70, p < 0.001), pretreatment GGT levels (HR/CI: 1.004/1.003-1.006, p < 0.001), alanine aminotransferase level (HR/CI: 0.996/0.994-0.998, p = 0.001), and age (HR/CI: 1.06/1.04-1.07, p < 0.001). Regarding liver-related mortality, the independent factors included cirrhosis (HR/CI: 4.36/2.79-6.89, p < 0.001), pretreatment GGT levels (HR/CI: 1.006/1.004-1.008, p < 0.001), alanine aminotransferase level (HR/CI: 0.993/0.990-0.997, p = 0.001), age (HR/CI: 1.03/1.01-1.05, p < 0.001), and fatty liver disease (HR/CI: 0.30/0.15-0.59, p = 0.001). Pretreatment GGT levels were also independently predictive of non-liver-related mortality (HR/CI: 1.003/1.000-1.005, p = 0.03). The results remained consistent after excluding the patients with a history of alcohol use. A dose-dependent manner of <25, 25-75, and >75 percentile of pretreatment GGT levels was observed with respect to the all-cause mortality (trend p < 0.001). Pretreatment serum GGT levels predicted all-cause, liver-related, and non-liver-related mortality in patients with CHB treated with NAs.

Development of a Gene-Based Soybean-Origin Discrimination Method Using Allele-Specific Polymerase Chain Reaction.

A low soybean self-sufficiency rate in South Korea has caused a high import dependence and considerable price variation between domestic and foreign soybeans, causing the false labeling of foreign soybeans as domestic. Conventional soybean origin discrimination methods prevent a single-grain analysis and rely on the presence or absence of several compounds or concentration differences. This limits the origin discrimination of mixed samples, demonstrating the need for a method that analyzes individual grains. Therefore, we developed a method for origin discrimination using genetic analysis. The whole-genome sequencing data of the Williams 82 reference cultivar and 15 soybean varieties cultivated in South Korea were analyzed to identify the dense variation blocks (dVBs) with a high single-nucleotide polymorphism density. The PCR primers were prepared and validated for the insertion-deletion (InDel) sequences of the dVBs to discriminate each soybean variety. Our method effectively discriminated domestic and foreign soybean varieties, eliminating their false labeling.

A hypothalamus-habenula circuit regulates psychomotor responses induced by cocaine.

Administration of cocaine increases synaptic dopamine levels by blocking dopamine reuptake and leads to increased locomotor activity and compulsive drug-seeking behaviour. It has been suggested that the lateral hypothalamus (LH) or lateral habenula (LHb) is involved in drug-seeking behaviours. To explore the role of the LH and the LHb in cocaine-induced psychomotor responses, we tested whether modulation of the LH or the LH-LHb circuit affects cocaine-induced locomotion. Cocaine-induced locomotor activity and dopamine release were suppressed by the activation of the LH with 2-[2,6-difluoro-4-[[2-[(phenylsulfonyl)amino]ethyl]thio]phenoxy]acetamide (PEPA), an AMPA receptor agonist. When the LH was inhibited by microinjection of a GABA receptor agonists mixture prior to cocaine injection, the cocaine's effects were enhanced. Furthermore, optogenetic activation of the LH-LHb circuit attenuated the cocaine-induced locomotion, while optogenetic inhibition of the LH-LHb circuit increased it. In vivo extracellular recording found that the LH sent a glutamatergic projection to the LHb. These findings suggest that the LH glutamatergic projection to the LHb plays an active role in the modulation of cocaine-induced psychomotor responses.

Application of attentional bias modification to reduce attentional bias and emotional reactivity to stress in mildly depressed individuals.

This study aims to verify the effectiveness of attentional bias modification (ABM) in reducing attentional bias related to depression, particularly in the later stages of attention as a pattern of difficulty in disengagement from depression-relevant stimuli, and to assess its effects on emotional reactivity to stress. A total of 78 participants were separated into four groups based on their levels of depression (minimal and mild) and the types of ABM. The positive ABM (pABM) trained participants to disengage their attention from depression-relevant stimuli and directed their attention toward more positive stimuli, whereas the neutral ABM (nABM) was designed to have no effect. The participants underwent a free-viewing task by eye tracker both before and after ABM to observe changes in attentional bias. Subsequently, they reported their emotional response after a stress-inducing task. The group of mildly depressed participants receiving pABM showed significantly less attention to depression-relevant negative affective stimuli and reported significantly decreased negative emotional reactivity to stress compared to the other groups. pABM had an effect on decreasing difficulty in disengaging from depression-relevant negative affective words (DW). However, it did not increase the dwell time on positive affective words (PW) in the current study. This might be due to the short duration of the application of ABM. The current study conducted ABM twice in 1 day, and this might not be enough to increase the dwell time on PA. This study verified that the ABM effectively decreased the attentional bias of depression and its relevant symptom, emotional reactivity to stress.

The role of direct contact in forming peace-oriented international relations of a divided country: Focusing on the division of the Korean Peninsula.

BACKGROUND: The division of the Korean peninsula involved many neighbouring countries in the Korean War. The relations with those countries have since been reorganised due to active exchange. This study examined how the quantity and quality of contact with traditional alliance (US and Japan) and strategic partner (China and Russia) countries affected their national images. METHODS: To this end, this study analyzed the relation with the national image by measuring the quantity and quality of contact of an individual with each country. The quantity of contact included an evaluation of the individual's subjective amount of contact, contact path, and contact status, and the quality of contact was measured as an evaluation for the pleasure, competitiveness, intimacy, spontaneity, and necessity when contacting each country's culture. A total of 387 participants were divided into two groups based on the presence of direct contact and the quantity and quality of their contact and national images were examined. The participants were followed by a completion of the self-questionnaires including the Culture Experience Questionnaire, National Image Questionnaire, and demographic information questionnaire. RESULTS: The results of this study are as follow: first, regardless of the type of country, the national image was highly correlated with the degree of subjective contact evaluated by individuals, but there was a weak tendency with contact quality. Second, there was no significant interaction between the country type and contact status for national image, however, different national images for each country were detected. In other word, for contact quantity, contact groups showed more positive national images compared to non-contact groups in Russia, but not Japan, China, and the US. For contact quality, the positive contact experience group showed more positive national images compared to the negative contact experience group, but only in traditional alliance countries. CONCLUSION: This study highlights the importance of implementing different strategies for countries to maintain peaceful international relations.

Pharmacological and Nonpharmacological Treatments for Painful Diabetic Peripheral Neuropathy.

Diabetic peripheral neuropathy (DPN) is one of the most prevalent chronic complications of diabetes. The lifetime prevalence of DPN is thought to be >50%, and 15%-25% of patients with diabetes experience neuropathic pain, referred to as "painful DPN." Appropriate treatment of painful DPN is important because this pain contributes to a poor quality of life by causing sleep disturbance, anxiety, and depression. The basic principle for the management of painful DPN is to control hyperglycemia and other modifiable risk factors, but these may be insufficient for preventing or improving DPN. Because there is no promising diseasemodifying medication for DPN, the pain itself needs to be managed when treating painful DPN. Drugs for neuropathic pain, such as gabapentinoids, serotonin-norepinephrine reuptake inhibitors, tricyclic antidepressants, alpha-lipoic acid, sodium channel blockers, and topical capsaicin, are used for the management of painful DPN. The U.S. Food and Drug Administration (FDA) has approved pregabalin, duloxetine, tapentadol, and the 8% capsaicin patch as drugs for the treatment of painful DPN. Recently, spinal cord stimulation using electrical stimulation is approved by the FDA for the treatment for painful DPN. This review describes the currently available pharmacological and nonpharmacological treatments for painful DPN.

A survey on the awareness, current management, and barriers for non-alcoholic fatty liver disease among the general Korean population.

Non-alcoholic fatty liver disease (NAFLD) is often diagnosed incidentally during medical evaluation for diseases other than liver disease or during health checkups. This study aimed to investigate the awareness, current status, and barriers to the management of NAFLD in the general population. This cross-sectional study used an online survey, which consisted of 3-domain and 18-item questionnaires. The content validity index for each item of the questionnaire was rated above 0.80. Most respondents (72.8%) reported having heard of the term 'NAFLD', and a large proportion of the general population (85.7%) recognized the possibility of developing fatty liver without consuming alcohol. Awareness of the terminology of NAFLD and that NAFLD is a disease that needs to be managed is relatively high. However, the knowledge that NAFLD can progress to end-stage liver disease and new cardiovascular diseases is lacking. Only 25.7% of the general population is aware that NAFLD increases the incidence of heart and cerebrovascular diseases. Only 44.7% of those who were incidentally diagnosed during a health check-up were provided with any specific guidance on NAFLD, and more than half (55.3%) were not provided with education or guidance on NAFLD or did not remember it. Only 40.2% of people diagnosed with NAFLD incidentally visited a clinic. The reason for not visiting a clinic for the evaluation of NAFLD varied greatly depending on sex and age group. Only 40.2% of patients visited the clinic after being diagnosed with NAFLD. The reasons for not visiting the clinic after NAFLD diagnosis differed significantly according to sex and age.

Mediation of mPFC-LHb pathway in acupuncture inhibition of cocaine psychomotor activity.

The medial prefrontal cortex (mPFC) and the lateral habenula (LHb) play roles in drug addiction and cognitive functions. Our previous studies have suggested that acupuncture at Shenmen (HT7) points modulates mesolimbic reward system in order to suppress drug-induced addiction behaviours. To explore whether an mPFC-LHb circuit mediates the inhibitory effects of acupuncture on addictive behaviours, we examined the projection from mPFC to LHb, excitation of mPFC neurons during acupuncture stimulation, the effects of optogenetic modulation of mPFC-LHb on HT7 inhibition of cocaine-induced locomotion and the effect of mPFC lesion on HT7 inhibition of nucleus accumbens (NAc) dopamine release. Acupuncture was applied at bilateral HT7 points for 20 s, and locomotor activity was measured in male Sprague-Dawley rats. Although cocaine injection significantly increased locomotor activity, HT7 acupuncture suppressed the cocaine-induced locomotion. The inhibitory effect of HT7 on cocaine-enhanced locomotion was blocked by optogenetic silencing of the mPFC-LHb circuit. In vivo extracellular recordings showed that HT7 acupuncture evoked an increase in the action potentials of mPFC neurons. Optopatch experiment proved glutamatergic projections from mPFC to LHb. HT7 acupuncture suppressed NAc dopamine release following cocaine injection, which was blocked by electrolytic lesion of mPFC. These results suggest the mediation of mPFC-LHb circuit in the inhibitory effects of acupuncture on cocaine psychomotor activity in rats.

Production of Feline Universal Erythrocytes with Methoxy Polyethylene Glycol.

Blood group mismatch in veterinary medicine is a significant problem in blood transfusion, sometimes leading to severe transfusion reactions and even patient death. Blood groups vary from species to species and there are three known blood groups in cats: A, B and AB. While A-type cats are most common, there is a shortage of feline B-type blood groups in cats. By using methoxy polyethylene glycol (mPEG) to protect antigenic epitopes on red blood cells (RBCs), we aimed to find the optimal conditions for the production of feline universal RBCs. The surfaces of feline A-type RBCs were treated with mPEG at various molecular weights and concentrations. Agglutination tests showed that the coating of feline A-type RBCs with mPEG of 20 kDa and 2 mM blocked hemagglutination to feline anti-A alloantibodies over 8 h. While no differences in RBC size and shape between intact and mPEG-treated RBCs were seen, coating RBCs with mPEG inhibited the binding of feline anti-A alloantibodies. Furthermore, the mPEG-treated RBCs did not cause spontaneous hemolysis or osmotic fragility, compared to control RBCs. According to a monocyte monolayer assay, mPEG treatment significantly reduced feline anti-A antibody-mediated phagocystosis of RBCs. These results confirm the potential of using activated mPEG on feline A-type RBC to create universal erythrocytes for transfusion to B-type cats.

Serum steroid profile captures metabolic phenotypes in adults with classic congenital adrenal hyperplasia.

OBJECTIVES: Adult patients with classic congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency have an increased risk of metabolic diseases. We aimed to investigate whether liquid chromatography-mass spectrometry (LC-MS)-based serum steroid profiling reveals metabolic phenotypes in adults with classic CAH. DESIGN AND METHODS: This study prospectively enrolled 63 adult patients with CAH and 38 healthy volunteers. The levels of the 24 steroids were quantified in the morning serum using LC-MS. Unsupervised clustering algorithms were applied to the serum steroid profiles to identify unique patterns associated with metabolic syndrome. RESULTS: Serum steroid profiles of patients with CAH were clearly delineated from those of healthy controls with a higher degree of interindividual heterogeneity. The unsupervised clustering algorithm divided CAH patients into two clusters based on serum steroid profile. Cluster 2 showed higher serum levels of glucocorticoids and androgens than cluster 1. The prevalence of metabolic syndrome was significantly higher in cluster 2 than in cluster 1 (37.8 % vs. 5.6 %, P = 0.011). Other clinical characteristics, including age, sex, body mass index, CAH subtypes, and glucocorticoid dose, did not differ between the two clusters. The multivariate logistic regression model of selective 15 steroids could discriminate metabolic syndrome in patients with CAH with an area under the receiver operating characteristic curve of 0.832 (95 % confidence interval:0.732-0.933). CONCLUSIONS: Serum steroid profiles can be valuable biomarkers for estimating metabolic risk in adult patients with CAH.

Mediation of lateral hypothalamus orexin input to lateral habenula in the inhibitory effects of mechanical stimulation on psychomotor responses induced by cocaine.

Introduction: The lateral hypothalamus (LH) plays an important physiological role in brain function and also plays an important role in substance abuse. The neuropeptides called orexin (or hypocretins) have been identified as being located exclusively in the cell bodies of the LH. Our previous studies have demonstrated that mechanical stimulation (MS) of the ulnar nerve produces strong inhibitory effects on cocaine addiction-like behaviors through activation of LH projection to the lateral habenula (LHb). Methods: Therefore, the present study hypothesized that ulnar MS would suppress the psychomotor responses induced by cocaine through the orexinergic LH-to-LHb pathway. Results: Ulnar MS attenuated cocaine enhancement of locomotor activity and 50-kHz ultrasonic vocalizations, which was prevented by antagonism of orexin-receptor type 2 (OX2R) in the LHb. Injection of orexin-A into the LHb reduced the cocaine-induced psychomotor responses. MS of the ulnar nerve excited LH orexinergic neurons. In addition, the excitation of LHb neurons by MS was blocked by the systemic administration of an OX2R antagonist. Discussion: These findings suggest that MS applied to the ulnar nerve recruits an orexinergic LH-to-LHb pathway to suppress the psychomotor responses induced by cocaine.

Attentional bias for high-calorie food cues by the level of hunger and satiety in individuals with binge eating behaviors.

Introduction: The abnormal hyperreactivity to food cues in individuals with binge eating behaviors could be regulated by hedonic or reward-based system, overriding the homeostatic system. The aim of the present study was to investigate whether attentional bias for food cues is affected by the level of hunger, maintaining the normal homeostatic system in individuals with binge eating behaviors. Methods: A total of 116 female participants were recruited and divided into four groups: hungry-binge eating group (BE) (n = 29), satiated BE (n = 29), hungry-control (n = 29), satiated control (n = 29). While participants completed a free-viewing task on high or low-calorie food cues, visual attentional processes were recorded using an eye tracker. Results: The results revealed that BE group showed longer initial fixation duration toward high-calorie food cues in both hunger and satiety condition in the early stage, whereas the control group showed longer initial fixation duration toward high-calorie food cues only in hunger conditions. Moreover, in the late stage, the BE group stared more at the high-calorie food cue, compared to control group regardless of hunger and satiety. Discussion: The findings suggest that automatic attentional bias for food cues in individuals with binge eating behaviors occurred without purpose or awareness is not affected by the homeostatic system, while strategic attention is focused on high-calorie food. Therefore, the attentional processing of food cues in binge eating group is regulated by hedonic system rather than homeostatic system, leading to vulnerability to binge eating.

Increased glutamate in type 2 diabetes in the Korean population is associated with increased plasminogen levels.

BACKGROUND: Glutamate is a major neurotransmitter, although it causes cytotoxicity and inflammation in nonneuronal organs. This study aimed to investigate the metabolic disorders in which glutamate, associated with type 2 diabetes onset, is induced in the liver. METHODS: An analysis of Korean community-based Ansan-Ansung cohort study data as well as functional research using in vitro and mouse models were performed. RESULTS: Groups with high plasma glutamate levels (T2, T3) had a significantly increased risk of diabetes incidence after 8 years, compared to the group with relatively low glutamate levels (T1). Analysis of the effect of glutamate on diabetes onset in vitro showed that glutamate induces insulin resistance by increasing glucose-related protein 78 (GRP78) and phosphoenolpyruvate carboxykinase (PEPCK) expression in SK-Hep-1 human liver cells. In addition, three different genes, FRMB4B, PLG, and PARD3, were significantly associated with glutamate and were identified via genome-wide association studies. Among glutamate-related genes, plasminogen (PLG) levels were most significantly increased in several environments in which insulin resistance was induced, and was also upregulated by glutamate. Glutamate-induced increase in PLG in liver cells was caused by metabotropic glutamate receptor 5 activation, and PLG levels were also upregulated after extracellular secretion. Moreover, glutamate increased the expression of plasminogen activator inhibitor-1 (PAI-1). Thus, extracellular secreted PLG cannot be converted to plasmin (fibrinolytic enzyme) by increased PAI-1. CONCLUSIONS: Increased glutamate is closely associated with the development of diabetes, and it may cause metabolic disorders by inhibiting the fibrinolytic system, which plays an important role in determining blood clots, a hallmark of diabetes.

Smart Materials with Dual Functionality: Repeatable Damage-Detection and Self-Healing.

Polymer materials are extensively used because of their excellent performance; however, when used for a long time, they break and eventually lose their original properties. Thus, smart polymer materials that can repeatedly detect and repair damage must be urgently developed to increase their durability and lifespan. In this study, a smart material with dual functionality (damage-detection and self-healing) is developed via a facile method of incorporating spiropyran (SP) beads, which exhibit changes in color and fluorescence when damaged, into a Diels-Alder (DA)-based self-healing matrix. When polyurethane (PU) is added to the DA-based matrix, the dual functionality exhibits a strong dependence on the proportion of PU. Because the PU ratio affects two opposing factors (damaged area and load-bearing capacity), the damage-detecting ability exhibits the best performance at 40 wt % PU, where both factors are optimized. A high healing efficiency of 96% is achieved via a dynamic DA reaction. In particular, the repeatability of the dual-functionality is successfully attained through the reversibility of the SP beads and DA networks, where the detection and healing efficiencies are reduced by 15 and 23%, respectively, after 10 cycles. Furthermore, the reprocessed fractured specimens exhibit excellent recyclability.

Activation of a hypothalamus-habenula circuit by mechanical stimulation inhibits cocaine addiction-like behaviors.

BACKGROUND: Mechanoreceptor activation modulates GABA neuron firing and dopamine (DA) release in the mesolimbic DA system, an area implicated in reward and substance abuse. The lateral habenula (LHb), the lateral hypothalamus (LH), and the mesolimbic DA system are not only reciprocally connected, but also involved in drug reward. We explored the effects of mechanical stimulation (MS) on cocaine addiction-like behaviors and the role of the LH-LHb circuit in the MS effects. MS was performed over ulnar nerve and the effects were evaluated by using drug seeking behaviors, optogenetics, chemogenetics, electrophysiology and immunohistochemistry. RESULTS: Mechanical stimulation attenuated locomotor activity in a nerve-dependent manner and 50-kHz ultrasonic vocalizations (USVs) and DA release in nucleus accumbens (NAc) following cocaine injection. The MS effects were ablated by electrolytic lesion or optogenetic inhibition of LHb. Optogenetic activation of LHb suppressed cocaine-enhanced 50 kHz USVs and locomotion. MS reversed cocaine suppression of neuronal activity of LHb. MS also inhibited cocaine-primed reinstatement of drug-seeking behavior, which was blocked by chemogenetic inhibition of an LH-LHb circuit. CONCLUSION: These findings suggest that peripheral mechanical stimulation activates LH-LHb pathways to attenuate cocaine-induced psychomotor responses and seeking behaviors.