Brain diseases affect millions of people and have a huge social and economic impact.The use of neural probes for studies in animals has been the main approach to increasing knowledge about neural network functioning.Ultimately,neuroscientists are trying to develop new and more effective therapeutic approaches to treating neurological disorders.The implementation of neural probes with multifunctionalities(electrical,optical,and fluidic interactions)has been increasing in the last few years,leading to the creation of devices with high temporal and spatial resolution.Increasing the applicability of,and elements integrated into,neural probes has also led to the necessity to create flexible interfaces,reducing neural tissue damage during probe implantation and increasing the quality of neural acquisition data.In this paper,we review the fabrication,characterization,and validation of several types of flexible neural probes,exploring the main advantages and drawbacks of these devices.Finally,future developments and applications are covered.Overall,this review aims to present the currently available flexible devices and future appropriate avenues for development as possible guidance for future engineered devices.

Background: In 2018, the government increased the fee for the magnetic resonance imaging (MRI) image deciphering services of the external hospital to discourage the redundant MRI scan and to induce appropriate use of the MRI services. It is important to evaluate the effect of the policy to provide the basis for establishing other MRI-related policies. Methods: The healthcare data of the patients who had brain MRI scans were organized by episode and analyzed using the panel study in order to find out the effect of the MRI-related policy on the substitution effect and the medical expenses. Results: As a result of the increase in the fee of deciphering the MRI image, there has been an uplift in deciphering the MRI scan of the external hospital. It implies that more hospitals chose to use the MRI scan taken by other clinics or hospitals, rather than the MRI scan taken at their own facilities. Conclusion The research results imply that a policy that facilitates the exchange of the medical image data between the hospitals is needed in order to establish an efficient management system of the healthcare resources. Such improvement is expected to reduce the social cost and contribute to the stability in the finance of national health insurance.

Objectives: The optimal duration of maintenance treatment for patients with first-episode schizophrenia (FES) remains unclear. We examined the first antipsychotic treatment duration and its association with re-initiation of treatment using a nationwide claim database. Methods: Data from the Health Insurance Review and Assessment Service database in South Korea for 2007–2016 were used. Linear regression analysis and Cox proportional hazard models were used to evaluate the associations between the duration of the first antipsychotic treatment, time to re-initiation of treatment, and occurrence of treatment re-initiation. Results: Of 30,143 patients with FES, 80.4% (n=24,231) received <2 years of the first antipsychotic treatment. In patients who discontinued treatment (n=23,030), the rate of treatment re-initiation was 74.2% (n=17,086). As the duration of the first antipsychotic treatment increased, the time to re-initiation of treatment decreased (β=-0.146, p<0.001); however, the rate of treatment re-initiation was relatively constant (hazard ratio=1.001, p<0.001). Conclusion Long-term antipsychotic treatment was not significantly associated with the rate of treatment re-initiation but showed a negative association with the time to re-initiation of treatment. Further research is needed to better understand the optimal treatment duration for FES.

OBJECTIVES: This study aimed to determine the prevalence of suicidal ideation among young and middle-aged adults, and explore the risk factors that affect suicidal ideation. METHODS: A descriptive study design was used for secondary data analysis. A total sample of 5,214 was drawn from two waves (2012–2013) of the 7th Korea Health Panel (KHP) survey. The KHP data were collected by a well-trained interviewer using the face-to-face method during home visits as well as self-report method. Descriptive statistics of frequency, percentage, chi-square test, and logistic regression analysis were performed using SPSS 22.0. RESULTS: The prevalence of suicidal ideation in young and middle-aged adults was 4.4% and 5.6%, respectively. For young adults, suicidal ideation risk was higher among those with low income or heavy drinking habits. In middle-aged adults, low income, poor perceived health status, negative perception of peer-compared health status, and negative social perspective were the major risk factors. CONCLUSION: There is considerable risk of suicidal ideation in adulthood. Opportunities for increased income, avoidance of heavy drinking, and the construction of positive subjective health status and social perspective should be considered in suicide prevention interventions for Korean young and middle-aged adults.
Adult* ; Diagnostic Self Evaluation ; Drinking ; House Calls ; Humans ; Korea ; Logistic Models ; Methods ; Middle Aged ; Prevalence ; Risk Factors* ; Statistics as Topic ; Suicidal Ideation* ; Suicide ; Young Adult

BACKGROUND/AIMS: Follicular thyroid carcinoma (FTC) and Hurthle cell carcinoma (HCC) of the thyroid are relatively uncommon thyroid malignancies in iodine-sufficient areas. In this study we evaluated the clinical behavior, prognostic factors and treatment outcomes of FTC and HCC in Korea. METHODS: This multicenter study included 483 patients with FTC and 80 patients with HCC who underwent an initial surgery between 1995 and 2006 in one of the four tertiary referral hospitals in Korea. We evaluated clinicopathological factors associated with distant metastases and recurrence during a median of 6 years of follow-up. RESULTS: HCC patients were significantly older (49 years vs. 43 years; p < 0.001) and had more lymphovascular invasions (22% vs. 14%; p = 0.03) compared with FTC patients. Distant metastases were confirmed in 40 patients (8%) in the FTC group and in two patients (3%) in the HCC group (p = 0.07). Distant metastases were significantly associated with older age, widely invasive cancer and extrathyroidal invasion. Only 14 patients (3%) had recurrent disease and there was no significant difference between FTC and HCC groups (p = 0.38). Recurrence was associated with larger tumor size and cervical lymph node metastasis. CONCLUSIONS: HCC patients were older and had more lymphovascular invasions than FTC patients. However, FTC and HCC patients had similar initial clinicopathological features. Older age, wide invasiveness and extrathyroidal invasion were independent risk factors for predicting distant metastases in FTC and HCC patients.
Adenocarcinoma, Follicular/*epidemiology/secondary/surgery ; Adult ; Age Factors ; *Diet ; Female ; Humans ; *Iodine ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; *Nutritional Status ; Republic of Korea/epidemiology ; Retrospective Studies ; Risk Factors ; Tertiary Care Centers ; Thyroid Neoplasms/*epidemiology/pathology/surgery ; Thyroidectomy ; Time Factors ; Treatment Outcome

BACKGROUND: Nausea and vomiting are predominant accompanying symptoms of migraine attacks. Although the underlying mechanism is not yet clear, gastric stasis is assumed to be the main factor. However, few studies have used direct methods to establish delayed gastric emptying of migraine patients. We compared interictal gastric motility between migraine patients and normal controls with the aid of gastric scintigraphy. METHODS: The study population comprised patients who had been diagnosed with episodic migraine, according to the International Classification of Headache Disorders, edition II. The entire study population was completely free of gastrointestinal symptoms during the headache-free period. Gastric scintigraphy was performed to determine the time to half emptying (T 1/2) and the percentage of radioactive material remaining in the stomach (%RMR) at 30, 60, 90, and 120 min. RESULTS: Twenty-six migraine patients and 12 normal controls were recruited. The mean T 1/2 did not differ between the two groups (101.8 vs 95.2 min; p=0.432). The %RMR values in the stomach at 30, 60, 90, and 120 min also did not differ significantly between the two groups [87.5% vs 88% (p=0.900), 70.8% vs 71.2% (p=0.950), 54.2% vs 53.3% (p=0.753), and 39.0% vs 37.3% (p=0.583), respectively]. CONCLUSIONS: There is no gastric stasis in patients with episodic migraine during headache-free periods. Our results suggest that the main mechanism underlying the nausea and vomiting in migraine patients is not a gastric stasis in interictal periods, but rather a central process, as a result of changes occurring in the brainstem during acute migraine attacks.
Brain Stem ; Gastric Emptying ; Gastroparesis ; Headache Disorders ; Humans ; Migraine Disorders ; Nausea ; Stomach ; Vomiting

BACKGROUND AND OBJECTIVES: Recent studies have reported that vascular endothelial growth factor (VEGF) and hypoxia-inducible factor (HIF)-1alpha are up-regulated in BRAF(V600E)-positive papillary thyroid carcinoma (PTC). We investigated whether papillary thyroid microcarcinomas (PTMCs) also exhibited increased expression of VEGF and HIF-1alpha. In addition, we analyzed the relationship between BRAF(V600E) mutation and clinicopathological parameters, as well as HIF-1alpha expression in PTMC. MATERIALS AND METHODS: We retrospectively selected 225 patients with PTMC. Immunohistochemical staining for HIF-1alpha and VEGF was performed using paraffinembedded PTMC tissue microarrays. BRAF(V600E) mutation status was analyzed by dideoxy sequencing. RESULTS: PTMCs larger than 0.5 cm tend to be related to aggressive clinicopathological features such as thyroid capsular invasion (p=0.023) and bilaterality (p=0.047). Immunoreactivity to HIF-1alpha (20.7%) and VEGF (30.2%) was more prominent in PTMCs as compared to normal follicular cells. However, HIF-1alpha and VEGF expression was not correlated with clinicopathological features. BRAF(V600E) mutation was found in 70.7% (159/225) of the PTMC cases. PTMCs harboring the BRAF(V600E) mutation exhibited larger tumor sizes as compared to PTMCs without the BRAF(V600E) mutation (p=0.038). However, BRAF(V600E) mutation status did not correlate with the expression of HIF-1alpha (p=0.623) or VEGF (p=0.990). CONCLUSION: HIF-1alpha and VEGF were more frequently detected in PTMCs as compared to normal thyroid tissues. However, BRAF(V600E) mutation status was not correlated with the expression of HIF-1alpha or VEGF in PTMCs.
Carcinoma ; Carcinoma, Papillary ; Humans ; Hypoxia-Inducible Factor 1 ; Proto-Oncogene Proteins B-raf ; Retrospective Studies ; Thyroid Gland ; Thyroid Neoplasms ; Vascular Endothelial Growth Factor A

BACKGROUND AND OBJECTIVES: The BRAFV600E mutation has been regarded as the leading cause of papillary thyroid cancer (PTC). However, the multi-step carcinogenic process induced by BRAFV600E has been remained to be elucidated in thyroid gland. In this study, to investigate staged development of papillary thyroid carcinoma, we observed the histo-pathological findings of thyroid gland from BRAFV600E transgenic mice with a period of 60 weeks. MATERIALS AND METHODS: We histologically inspected 3, 9, 20, 27, 39, 44, 48 and 60 week old BRAFV600E transgenic mice derived from FVB/N background mice with a bovine thyroglobulin promoter which are providing thyroid specific BRAFV600E expression. RESULTS: Thyroid glands from 3 and 9 week old BRAFV600E transgenic mice were enlarged and showed abnormal histologic feature such as distorted follicular architectures. The 20 and 27 week old BRAFV600E transgenic mice showed irregularly enlarged thyroid gland sprouting out above the carotid arteries. Thyroid gland derived from 39 week old mice showed reduced formation of intact follicular structure and increased solid area. Thyroid glands were entirely replaced by firm tumor mass composed of poorly differentiated cell at 44 weeks. Interestingly, we could observe tracheal invasion, surrounding muscle invasion in thyroid gland from 48 week old mice and detect lung metastasis in 60 week old mice. CONCLUSION: Thyroid specific expression of BRAFV600E induced staged development of thyroid cancer. This finding may support that BRAFV600E have a role in entire carcinogenic process such as tumor initiation, development and progression.
Animals ; Carcinoma ; Carotid Arteries ; Lung ; Mice ; Mice, Transgenic ; Muscles ; Neoplasm Metastasis ; Proto-Oncogene Proteins B-raf ; Thyroglobulin ; Thyroid Gland ; Thyroid Neoplasms

BACKGROUND: There are many studies regarding the effects of insulin on bone metabolism and changes in bone mineral density (BMD) in the setting of diabetes. The effect of prediabetes on BMD is not known. METHODS: A total of 802 men participated in the Korea Rural Genomic Cohort Study (in Geumsan County). According to the results of an oral glucose tolerance test, subjects were classified into normal, prediabetic, and diabetic categories. One hundred twenty-four subjects diagnosed with type 2 diabetes were excluded, leaving 678 subjects for the study inclusion. BMD was estimated with a quantitative ultrasonometer. RESULTS: The average BMD T scores of normal and prediabetic subjects were -1.34 +/- 1.42 and -1.33 +/- 1.30, respectively; there was no significant difference in the BMD T scores between these groups. The BMD T score was inversely associated with age and positively correlated with body weight, body mass index, total cholesterol, low density lipoprotein cholesterol, and HbA1c. On multiple linear regression analysis, low density lipoprotein cholesterol was the only statistically significant variable for prediabetes (beta = 0.007, P = 0.005). On the stepwise regression analysis, age (beta = -0.026, P < 0.001), the body mass index (beta = 0.079, P < 0.001), and low density lipoprotein cholesterol (beta = 0.004, P = 0.016) were significant variables for prediabetes. CONCLUSIONS: There was no significant difference in the BMD T score between the normal and prediabetic subjects. Further studies are needed regarding the association of fracture risk and changes in BMD with the development of overt diabetes.
Body Mass Index ; Body Weight ; Bone Density ; Cholesterol ; Cholesterol, LDL ; Cohort Studies ; Glucose Tolerance Test ; Humans ; Insulin ; Korea ; Linear Models ; Lipoproteins ; Male ; Prediabetic State

Members of the inhibitors of differentiation (Id) family of helix-loop-helix (HLH) proteins are known to play important roles in the proliferation and differentiation of many cell types. Thyroid-stimulating hormone (TSH) regulates proliferation and differentiation by activating TSH receptor (TSHR) in thyrocytes. In this study, we found that Id2, one of the Id family proteins, is a major target for regulation by TSH in FRTL-5 thyroid cells. TSH rapidly increases the Id2 mRNA level in FRTL-5 thyroid cells but the Id2 protein showed biphasic regulatory patterns, being transiently reduced and subsequently induced by TSH treatment. Transient reduction of Id2 protein was noted within 2 hr of TSH treatment and was mediated by proteasomal degradation. Moreover, reduced Id2 expression correlated with the activity of the phosphatidylinositol 3 kinase pathway, which is activated by TSH. Although TSH increases the activity of the Id2 promoter, TSH-induced activation of this promoter was independent of c-Myc. Id2 did not alter TTF-1- and Pax-8-mediated effects on the regulation of the Tg promoter. Thus, in summary, we found that TSH regulates Id2 expression, but that Id2 does not alter the expression of thyroid-specific genes, such as Tg, in FRTL-5 thyroid cells.
1-Phosphatidylinositol 3-Kinase/metabolism ; Animals ; Cattle ; Cell Differentiation ; Cell Proliferation ; *Gene Expression Regulation ; Inhibitor of Differentiation Protein 2/metabolism ; Insulin/metabolism ; Paired Box Transcription Factors/metabolism ; Promoter Regions, Genetic ; Proto-Oncogene Proteins c-myc/metabolism ; Rats ; Thyroglobulin/metabolism ; Thyroid Gland/*cytology ; Thyrotropin/*metabolism