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The indolent nature and favorable outcomes associated with papillary thyroid microcarcinoma have prompted numerous prospective studies on active surveillance (AS) and its adoption as an alternative to immediate surgery in managing low-risk thyroid cancer. This article reviews the current status of AS, as outlined in various international practice guidelines. AS is typically recommended for tumors that measure 1 cm or less in diameter and do not exhibit aggressive subtypes on cytology, extrathyroidal extension, lymph node metastasis, or distant metastasis. To determine the most appropriate candidates for AS, factors such as tumor size, location, multiplicity, and ultrasound findings are considered, along with patient characteristics like medical condition, age, and family history. Moreover, shared decision-making, which includes patient-reported outcomes such as quality of life and cost-effectiveness, is essential. During AS, patients undergo regular ultrasound examinations to monitor for signs of disease progression, including tumor growth, extrathyroidal extension, or lymph node metastasis. In conclusion, while AS is a feasible and reliable approach for managing lowrisk thyroid cancer, it requires careful patient selection, effective communication for shared decision-making, standardized follow-up protocols, and a clear definition of disease progression.
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Background/Aims@#Besifovir dipivoxil maleate (BSV) and tenofovir alafenamide fumarate (TAF) have been recently approved in Korea as the initial antiviral agents for chronic hepatitis B (CHB).However, the real-world outcome data for these drugs remain limited. Therefore, we conducted a noninferiority analysis using real-world data to compare the clinical outcomes of the two nucleotide analogs in treatment-naïve patients with CHB. @*Methods@#We retrospectively investigated a cohort of patients with CHB who received BSV or TAF as first-line antiviral agents. The endpoints were virological response (VR) and liver-related clinical outcomes. @*Results@#A total of 537 patients, consisting of 202 and 335 patients administered BSV and TAF, respectively, were followed up for 42 months. No significant difference was observed between the VRs of the patients from the two groups. The rates of biochemical response, virologic breakthrough, and incidence rates of hepatocellular carcinoma did not differ between the groups. However, the hepatitis B e antigen seroclearance rate was higher and the renal function declined less in the BSV group. Multivariable analysis indicated older age, alcohol abuse, cirrhosis and ascites, and lower serum HBV DNA level to be independently associated with increased hepatocellular carcinoma risk. The 1:1 propensity score-matched analysis with 400 patients showed VR rates of 85.0% and 88.7% in the BSV and TAF group patients, respectively, at 2 years. The absolute value of the 95% confidence interval for the difference (–0.04 to 0.12) satisfied the a priori limit of a noninferiority of 0.15. @*Conclusions@#BSV is noninferior to TAF in terms of VR, and their clinical outcomes are comparable to CHB.
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Objectives@#The purpose of this study was to examine the association between social capital and depression in adults in their 20s. @*Methods@#The study used data from the Community Health Survey 2019 (CHS 2019). The CHS 2019 covered a representative sample of 229099 adults from 17 census tracts in the Republic of Korea, of which 19589 adults in their 20s were taken as subjects for this study. The subjects completed a survey with questions regarding demographic characteristics, built environment and social capital. The symptoms of depression were evaluated through the Patient Health Questionnaire (PHQ)-9. Multiple logistic regression was used to examine whether social capital was associated with depression. @*Results@#The multiple logistic regression results indicated that social capital was associated with depression in adults in their 20s. When demographic characteristics and built environment were included in the analysis, trust, contact with relatives, contact with friends, and social activities were associated with depression in adults in their 20s. @*Conclusion@#A lack of social capital was associated with depression in Korean adults in their 20s. Our study suggests a need to look beyond individual factors to intervene in national and community social capital and prevent depression in adults in their 20s.
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Social capital, defined as an individual’s social relationships and participation in community networks, encompasses resources, such as the exchange of favors, maintenance of group norms, stocks of trust, and exercise of sanctions available to members of social groups. Social capital may lower the risk of mental disorders while increasing the resilience capacity, adaptation, and recovery. Interventions targeting social capital may offer a cost-effective approach to preventing and ameliorating these conditions. This study evaluated the concept and importance of social capital because mental well-being is influenced by individual characteristics, the socioeconomic situation, and broader environmental factors to which individuals are exposed. Recognizing the growing significance of social capital in this context, the study examined its role, its relationship with depression, and the potential importance of social capital in South Korea. Although the definition of social capital is broad, the emphasis is placed on the role of linking social capital. Moving beyond an individual-centric perspective on identifying the factors contributing to depression, this paper suggests that social capital can serve as a crucial starting point for changing the environment to which individuals belong, i.e., structural and intermediary determinants. In the macrolevel perspective of mental health intervention, this paper proposes the need to attribute significance and awareness to numerous studies already implemented in various local communities through social capital.
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This article describes common comorbid condtion of the autism spectrum disorder (ASD) and recommends treatment guidelines of pharmacotherapy for patients with ASD. More than 95% of people with ASD have at least one additional disorder and guidelines how to evaluate and treat comorbid conditions in patients with ASD and 7 recommendations for treatment with medication for ASD.
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Recently, the most commonly used method for voice rehabilitation in total laryngectomy patients is to maintain tracheoesophageal shunt speech after inserting a voice prosthesis. One of the most common side effects, besides valve deterioration, is periprosthetic leakage due to dilatation of the tracheoesophageal shunt. Tissue implantation may be considered as one of the conservative treatments before attempting surgical treatment. When tissue implantation is attempted more than once, the treatment success rate is close to 90%. The authors experienced a case in which an 86-year-old patient developed aspiration pneumonia due to periprosthetic leakage. The patient refused surgical treatment. He was treated successfully for injecting hyaluronic acid filler 3 times and has been without a leakage for 9 months. This procedure can be considered as an alternative method to treat periprosthetic leakage.
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Objective@#This study aimed to validate the risk stratification system (RSS) and biopsy criteria for cervical lymph nodes (LNs) proposed by the Korean Society of Thyroid Radiology (KSThR). @*Materials and Methods@#This retrospective study included a consecutive series of preoperative patients with thyroid cancer who underwent LN biopsy, ultrasound (US), and computed tomography (CT) between December 2006 and June 2015. LNs were categorized as probably benign, indeterminate, or suspicious according to the current US- and CT-based RSS and the size thresholds for cervical LN biopsy as suggested by the KSThR. The diagnostic performance and unnecessary biopsy rates were calculated. @*Results@#A total of 277 LNs (53.1% metastatic) in 228 patients (mean age ± standard deviation, 47.4 years ± 14) were analyzed. In US, the malignancy risks were significantly different among the three categories (all P 5 mm LNs, P ≥ 0.177). The criteria covering only suspicious LNs showed higher specificity and lower unnecessary biopsy rates than the current criteria, while maintaining sensitivity in all imaging modalities. @*Conclusion@#Integrative evaluation of US and CT helps in reducing the proportion of indeterminate LNs and the malignancy risk among them. Nodal size did not affect the malignancy risk of LNs, and the addition of indeterminate LNs to biopsy candidates did not have an advantage in detecting LN metastases in all imaging modalities.
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Background/Aims@#Chronic hepatitis C is a major risk factor for liver cirrhosis, hepatocellular carcinoma, and hepatic failure. Although traditional practices, including acupuncture, tend to increase the risk of HCV infection, the association remains controversial. Therefore, the current meta-analytical study was undertaken to evaluate the risks of acupuncture and hepatitis C transmission. @*Methods@#Two researchers independently screened studies from the databases encompassing the period from inception to May 12, 2022. Baseline demographics, HCV transmission OR, and 95% CIs were extracted, pooled, and analyzed using random-effect models.Subgroup analyses utilizing study design and ethnicity were performed. Heterogeneity and publication bias were analyzed using the Higgins I2 test and funnel plots, respectively. @*Results@#In all, 28 studies with 194,826 participants (178,583 controls [91.7%] vs. 16,243 acupuncture users [8.3%]) were included in the final analysis. The pooled analysis showed that acupuncture users had a significantly higher HCV transmission rate than controls with heterogeneity (OR, 1.84 [1.46–2.32]; p<0.001; I2 =80%). In the subgroup analysis, both cross-sectional case-control (n=14; OR, 1.96 [1.47–2.61]; p<0.001; I2 =88%) and cross-sectional studies (n=12; OR, 1.85 [1.32–2.61]; p<0.001; I2 =0%) showed significantly higher HCV infection rates in the acupuncture group than in the control group. Both Asian and non-Asian acupuncture users showed a higher HCV transmission risk than the controls (all Ps <0.001). No significant publication bias was observed. @*Conclusions@#Our findings indicate that acupuncture increases the risk of HCV transmission. Due to HCV's contagiousness, unsafe medical and social practices (including acupuncture) should be performed with caution.
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Ultrasonography (US) is a primary imaging modality for diagnosing nodular thyroid disease and has an essential role in identifying the most appropriate management strategy for patients with nodular thyroid disease. Standardized imaging techniques and reporting formats for thyroid US are necessary. For this purpose, the Korean Society of Thyroid Radiology (KSThR) organized a task force in June 2021 and developed recommendations for standardized imaging technique and reporting format, based on the 2021 KSThR consensus statement and recommendations for US-based diagnosis and management of thyroid nodules. The goal was to achieve an expert consensus applicable to clinical practice.
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Snapping triceps syndrome is a rare disease in which the distal portion of the medial triceps dislocates over the medial epicondyle during flexion of the elbow. It is usually accompanied with ulnar nerve dislocation and double snapping is clinically important feature. Dynamic ultrasonography is useful diagnostic tool for snapping triceps syndrome and ulnar nerve dislocation. But it is often misdiagnosed as ulnar nerve dislocation alone. This review reports a case of 28-year-old professional golfer who had a single snapping on elbow, misdiagnosed as ulnar nerve dislocation alone and eventually diagnosed as ulnar nerve dislocation and snapping triceps syndrome and also reflects factors that are overlooked through first and second operations.
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Background and Objectives@#This study aimed to investigate the protective effect of polydeoxyribonucleotide (PDRN) against skin flap necrosis in a murine skin flap model.Materials and Method Twenty mice with rectangular skin flaps on the dorsum were randomly divided into the PDRN (n=10) and pentobarbital sodium (PBS) (n=10) injection groups. PDRN (8 mg/kg) was subdermally injected at 12 different points immediately after the operation. After 7 days, the flap perfusions were evaluated using a laser speckle contrast imaging (LSCI) system, and specimens were collected for immunohistochemistry analysis. @*Results@#The percentage of survival area relative to the total flap area was significantly higher in the PDRN group (60.87%±7.63%) than in the PBS group (45.23%±10.72%) (p<0.05). The mean LSCI perfusion signal of the distal part of the skin flap in the PBS group was 0.57±0.12, and that in the PDRN group was 0.74±0.13 (p<0.05). The PDRN group had a significantly lower interleukin 1 beta expression than the PBS group and higher vascular endothelial growth factor α expression than the PBS group (p<0.05). @*Conclusion@#These findings suggest that subdermally injected PDRN is more effective in enhancing flap survival during necrosis.
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Purpose@#This study evaluated thyroid cancer risk in a lung cancer screening population according to the presence of an incidental thyroid nodule (ITN) detected on low-dose chest computed tomography (LDCT). @*Methods@#Of 47,837 subjects who underwent LDCT, a lung cancer screening population according to the National Lung Screening Trial results was retrospectively enrolled. The prevalence of ITN on LDCT was calculated, and the ultrasonography (US)/fine-needle aspiration (FNA)–based risk of thyroid cancer according to the presence of ITN on LDCT was compared using the Fisher exact or Student t-test as appropriate. @*Results@#Of the 2,329 subjects (female:male=44:2,285; mean age, 60.9±4.9 years), the prevalence of ITN on LDCT was 4.8% (111/2,329). The incidence of thyroid cancer was 0.8% (18/2,329, papillary thyroid microcarcinomas [PTMCs]) and was higher in the ITN-positive group than in the ITN-negative group (3.6% [4/111] vs. 0.6% [14/2,218], P=0.009). Among the 2,011 subjects who underwent both LDCT and thyroid US, all risks were higher (P<0.001) in the ITNpositive group than in the ITN-negative group: presence of thyroid nodule on US, 94.1% (95/101) vs. 48.6% (928/1,910); recommendation of FNA according to the American Thyroid Association guideline and Korean Thyroid Imaging Reporting and Data System guideline, 41.2% (42/101) vs. 2.4% (46/1,910) and 39.6% (40/101) vs. 1.9% (37/1,910), respectively. @*Conclusion@#Despite a higher risk of thyroid cancer in the LDCT ITN-positive group than in the ITN-negative group in a lung cancer screening population, all cancers were PTMCs. A heavy smoking history may not necessitate thorough screening US for thyroid incidentalomas.
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Purpose@#Although the taller-than-wide (TTW) sign has been regarded as one of the most specific ultrasound (US) features of thyroid malignancy, uncertainty still exists regarding the US probe’s orientation when evaluating it. This study investigated which US plane would be optimal to identify the TTW sign based on malignancy risk stratification using a registry-based imaging dataset. @*Methods@#A previous study by 17 academic radiologists retrospectively analyzed the US images of 5,601 thyroid nodules (≥1 cm, 1,089 malignant and 4,512 benign) collected in the webbased registry of Thyroid Imaging Network of Korea through the collaboration of 26 centers. The present study assessed the diagnostic performance of the TTW sign itself and fine needle aspiration (FNA) indications via a comparison of four international guidelines, depending on the orientation of the US probe (criterion 1, transverse plane; criterion 2, either transverse or longitudinal plane). @*Results@#Overall, the TTW sign was more frequent in malignant than in benign thyroid nodules (25.3% vs. 4.6%). However, the statistical differences between criteria 1 and 2 were negligible for sensitivity, specificity, and area under the curve (AUC) based on the size effect (all P0.05, respectively). @*Conclusion@#A longitudinal US probe orientation provided little additional diagnostic value over the transverse orientation in detecting the TTW sign of thyroid nodules.
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Objective@#To compare core needle biopsy (CNB) and repeat fine-needle aspiration (rFNA) to reduce the rate of diagnostic surgery and prevent unnecessary surgery in nodules initially diagnosed as atypia/follicular lesions of undetermined significance (AUS/FLUS). @*Materials and Methods@#This study included 231 consecutive patients (150 female and 81 male; mean age ± standard deviation, 51.9 ± 11.7 years) with 235 thyroid nodules (≥ 1 cm) initially diagnosed as AUS/FLUS, who later underwent both rFNA and CNB. The nodules that required diagnostic surgery after the biopsy were defined using three different scenarios according to the rFNA and CNB results: criterion 1, surgery for low-risk indeterminate (categories I and III); criterion 2, surgery for high-risk indeterminate (categories IV and V); and criterion 3, surgery for all indeterminate nodules (categories I, III, IV, and V). We compared the expected rates of diagnostic surgery between CNB and rFNA in all 235 nodules using the three surgical criteria. In addition, the expected rates of unnecessary surgery (i.e., surgery for benign pathology) were compared in a subgroup of 182 nodules with available final diagnoses. @*Results@#CNB showed significantly lower rates of nondiagnostic, AUS/FLUS, and suspicious for malignancy diagnoses (p ≤ 0.016) and higher rates of follicular neoplasm or suspicious for a follicular neoplasm (p < 0.001) and malignant diagnoses (p = 0.031). CNB showed a significantly lower expected rate of diagnostic surgery than rFNA for criterion 1 (29.8% vs. 48.1%, p < 0.001) and criterion 3 (46.4% vs. 55.3%, p = 0.029), and a significantly higher rate for criterion 2 (16.6% vs. 7.2%, p = 0.001). CNB showed a significantly lower expected rate of unnecessary surgery than rFNA for criterion 1 (18.7% vs. 29.7%, p = 0.024). @*Conclusion@#CNB was superior to rFNA in reducing the rates of potential diagnostic surgery and unnecessary surgery for nodules initially diagnosed as AUS/FLUS in a scenario where nodules with low-risk indeterminate results (categories I and III) would undergo surgery.
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Objective@#This study aimed to explore the myelin volume change in patients with mild traumatic brain injury (mTBI) with post-concussion syndrome (PCS) using a multidynamic multiecho (MDME) sequence and automatic whole-brain segmentation. @*Materials and Methods@#Forty-one consecutive mTBI patients with PCS and 29 controls, who had undergone MRI including the MDME sequence between October 2016 and April 2018, were included. Myelin volume fraction (MVF) maps were derived from the MDME sequence. After three dimensional T1-based brain segmentation, the average MVF was analyzed at the bilateral cerebral white matter (WM), bilateral cerebral gray matter (GM), corpus callosum, and brainstem. The Mann–Whitney U-test was performed to compare MVF and myelin volume between patients with mTBI and controls. Myelin volume was correlated with neuropsychological test scores using the Spearman rank correlation test. @*Results@#The average MVF at the bilateral cerebral WM was lower in mTBI patients with PCS (median [interquartile range], 25.2% [22.6%–26.4%]) than that in controls (26.8% [25.6%–27.8%]) (p = 0.004). The region-of-interest myelin volume was lower in mTBI patients with PCS than that in controls at the corpus callosum (1.87 cm3 [1.70–2.05 cm3 ] vs. 2.21 cm3 [1.86– 3.46 cm3 ]; p = 0.003) and brainstem (9.98 cm3 [9.45–11.00 cm3 ] vs. 11.05 cm3 [10.10–11.53 cm3 ]; p = 0.015). The total myelin volume was lower in mTBI patients with PCS than that in controls at the corpus callosum (0.45 cm3 [0.39–0.48 cm3 ] vs. 0.48 cm3 [0.45–0.54 cm3 ]; p = 0.004) and brainstem (1.45 cm3 [1.28–1.59 cm3 ] vs. 1.54 cm3 [1.42–1.67 cm3 ]; p = 0.042). No significant correlation was observed between myelin volume parameters and neuropsychological test scores, except for the total myelin volume at the bilateral cerebral WM and verbal learning test (delayed recall) (r = 0.425; p = 0.048). @*Conclusion@#MVF quantified from the MDME sequence was decreased at the bilateral cerebral WM in mTBI patients with PCS. The total myelin volumes at the corpus callosum and brainstem were decreased in mTBI patients with PCS due to atrophic changes.
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Skeletal muscle is now regarded as an endocrine organ based on its secretion of myokines and exerkines, which, in response to metabolic stimuli, regulate the crosstalk between the skeletal muscle and other metabolic organs in terms of systemic energy homeostasis. This conceptual basis of skeletal muscle as a metabolically active organ has provided insights into the potential role of physical inactivity and conditions altering muscle quality and quantity in the development of multiple metabolic disorders, including insulin resistance, obesity, and diabetes. Therefore, it is important to understand human muscle physiology more deeply in relation to the pathophysiology of metabolic diseases. Since monolayer cell lines or animal models used in conventional research differ from the pathophysiological features of the human body, there is increasing need for more physiologically relevant in vitro models of human skeletal muscle. Here, we introduce recent studies on in vitro models of human skeletal muscle generated from adult myogenic progenitors or pluripotent stem cells and summarize recent progress in the development of three-dimensional (3D) bioartificial muscle, which mimics the physiological complexity of native skeletal muscle tissue in terms of maturation and functionality. We then discuss the future of skeletal muscle 3D-organoid culture technology in the field of metabolic research for studying pathological mechanisms and developing personalized therapeutic strategies.
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Objective@#Emergency cricothyroidotomy is an infrequently performed procedure and post-procedural complications may result from attempting to pass a device with a large external diameter through the cricothyroid membrane. This study aimed to determine the maximum height of the cricothyroid membrane according to the patient’ s sex and age based on cervical-spine computed tomography (C-spine CT) in the emergency department (ED) and determine the appropriate endotracheal tube (ETT) size. @*Methods@#A retrospective analysis of patients was conducted from May 2014 to April 2020 in the ED. The data were obtained from medical records. Electronic calipers were used to measure the maximum height of the cricothyroid membrane in C-spine CT by an emergency physician and an emergency medicine resident. @*Results@#Six hundred and sixty-four patients were included in the study. The mean height of the cricothyroid membrane was 10.11±2.24 mm in males (n=351) and 8.90±1.84 mm in females (n=313) (P<0.001). In males, the cricothyroid membrane height showed significant variance between the ≥75-year-old and the 25-34-year-old groups (9.26±2.40 mm vs. 11.80±2.36 mm) (P<0.001). The tube size of the cricothyroidotomy equipment was suitable for more than 72.1% of patients when applied with an ETT (internal diameter ≤6.0 mm). @*Conclusion@#This study showed that the height of the cricothyroid membrane differed according to sex and also age in males. It may thus be necessary to consider anatomical differences according to sex and age when selecting the appropriate tube size to reduce complications during emergency cricothyroidotomy.
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Objective@#Preoperative differential diagnosis of follicular-patterned lesions is challenging. This multicenter cohort study investigated the clinicoradiological characteristics relevant to the differential diagnosis of such lesions. @*Materials and Methods@#From June to September 2015, 4787 thyroid nodules (≥ 1.0 cm) with a final diagnosis of benign follicular nodule (BN, n = 4461), follicular adenoma (FA, n = 136), follicular carcinoma (FC, n = 62), or follicular variant of papillary thyroid carcinoma (FVPTC, n = 128) collected from 26 institutions were analyzed. The clinicoradiological characteristics of the lesions were compared among the different histological types using multivariable logistic regression analyses. The relative importance of the characteristics that distinguished histological types was determined using a random forest algorithm. @*Results@#Compared to BN (as the control group), the distinguishing features of follicular-patterned neoplasms (FA, FC, and FVPTC) were patient’s age (odds ratio [OR], 0.969 per 1-year increase), lesion diameter (OR, 1.054 per 1-mm increase), presence of solid composition (OR, 2.255), presence of hypoechogenicity (OR, 2.181), and presence of halo (OR, 1.761) (all p < 0.05). Compared to FA (as the control), FC differed with respect to lesion diameter (OR, 1.040 per 1-mm increase) and rim calcifications (OR, 17.054), while FVPTC differed with respect to patient age (OR, 0.966 per 1-year increase), lesion diameter (OR, 0.975 per 1-mm increase), macrocalcifications (OR, 3.647), and non-smooth margins (OR, 2.538) (all p < 0.05). The five important features for the differential diagnosis of follicular-patterned neoplasms (FA, FC, and FVPTC) from BN are maximal lesion diameter, composition, echogenicity, orientation, and patient’s age. The most important features distinguishing FC and FVPTC from FA are rim calcifications and macrocalcifications, respectively. @*Conclusion@#Although follicular-patterned lesions have overlapping clinical and radiological features, the distinguishing features identified in our large clinical cohort may provide valuable information for preoperative distinction between them and decision-making regarding their management.
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Background/Aims@#Efficient anti-fibrotic therapies are required for the treatment of liver cirrhosis. Hydroxymethylglutaryl-coenzyme A reductase inhibitors (statins) and cyclooxygenase-2 (COX-2) inhibitors have been reported to have anti-fibrotic effects. Here, we investigated whether combined treatment with a statin and a COX-2 inhibitor has synergistic anti-fibrotic effects. @*Methods@#The effects of treatment strategies incorporating both simvastatin and a COX-2 inhibitor, NS-398, were investigated using an immortalized human hepatic stellate cell line (LX-2) and a hepatic fibrosis mouse model developed using thioacetamide (TAA) in drinking water. Cellular proliferation was investigated via 5-bromo-2-deoxyuridine uptake. Pro- and anti-apoptotic factors were investigated through Western blotting and real-time polymerase chain reaction analysis. @*Results@#The evaluation of the anti-proliferative effects on LX-2 cells showed that the observed effects were more pronounced with combination therapy than with single-drug therapy. Moreover, hepatic fibrosis and collagen deposition decreased significantly in TAA-treated mice in response to the combined treatment strategy. The mechanisms underlying the anti-fibrotic effects of the combination therapy were investigated. The effects of the combination therapy were correlated with increased expression levels of extracellular signal-regulated kinase 1/2 signaling molecules, upregulation of the Bax/Bcl-2 signaling pathway, inhibition of the transforming growth factor-β signaling pathway, and inhibition of tissue inhibitor of matrix metalloproteinases 1 and 2. @*Conclusions@#The combination of simvastatin and NS-398 resulted in a synergistic anti-fibrotic effect through multiple pathways. These findings offer a theoretical insight into the possible clinical application of this strategy for the treatment of advanced liver diseases with hepatic fibrosis.
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Purpose@#The aim of this multicenter study was to investigate the malignancy risk of minimally cystic thyroid nodules (MCTNs) using cyto-histopathologic diagnoses as the reference standard. @*Methods@#From June 2015 to September 2015, 5,601 thyroid nodules (≥1 cm) from 4,989 consecutive patients who underwent thyroid ultrasonography (US) at 26 institutions were retrospectively analyzed. Each thyroid nodule was categorized according to its cystic proportion: purely solid, minimally cystic (≤10%), and partially cystic (>10%). The malignancy risk of MCTNs was compared with those of purely solid nodules and partially cystic thyroid nodules (PCTNs). The malignancy risk of MCTNs was assessed according to echogenicity and the presence of suspicious US features. @*Results@#The prevalence of MCTNs was 22.5%. The overall malignancy risk of MCTNs was 8.8%, which was significantly lower than that of purely solid nodules (29.5%) (P0.05). MCTNs were associated with a higher risk of malignancy in hypoechoic nodules than in isohyperechoic nodules and in nodules with suspicious US features than in those without suspicious US features (all P<0.001). @*Conclusion@#The malignancy risk of MCTNs was significantly lower than that of purely solid nodules. MCTNs could be categorized as PCTNs rather than as solid nodules to increase the accuracy of the risk stratification system for thyroid nodules.