1,468 research outputs found

    Osteosarcoma in Korean children and adolescents

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    Osteosarcoma is the most frequent primary bone tumor. Advances in combination chemotherapy and surgical technique have greatly improved the survival of patients with osteosarcoma. In Korea, improvements in osteosarcoma treatment have been made over the past two decades. The 5-year event-free survival rate of Korean children and adolescents with localized disease is 64.6%, comparable to that of American or European patients. This article provides an overview of current therapies for osteosarcoma in Korea

    Review on the ecotoxicological impacts of plastic pollution on the freshwater invertebrate Daphnia

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    The environmental impacts of plastic pollution have recently attracted universal attention, especially in the aquatic environment. However, research has mostly been focused on marine ecosystems, even though freshwater ecosystems are equally if not more polluted by plastics. In addition, the mechanism and extent to which plastic pollution affects aquatic biota and the rates of transfer to organisms through food webs eventually reaching humans are poorly understood, especially considering leaching hazardous chemicals. Several studies have demonstrated extreme toxicity in freshwater organisms such Daphnia. When such keystone species are affected by ambient pollution, entire food webs are destabilized and biodiversity is threatened. The unremitting increase in plastic contaminants in freshwater environments would cause impairments in ecosystem functions and structure, leading to various kinds of negative ecological consequences. As various studies have reported the effects on daphnids, a consolidation of this literature is critical to discuss the limitations and knowledge gaps and to evaluate the risk posed to the aquatic environment. This review was undertaken due to the evident need to evaluate this threat. The aims were to provide a meaningful overview of the literature relevant to the potential impact of plastic pollution and associated contaminants on freshwater daphnids as primary consumers. A critical evaluation of research gaps and perspectives is conducted to provide a comprehensive risk assessment of microplastic as a hazard to aquatic environments. We outlined the challenges and limitations to microplastic research in hampering better-focused investigations that could support the development of new plastic materials and/or establishment of new regulations.Peer reviewe

    The Effect of Ca-P Coated Bovine Bone Mineral on Bone Regeneration around Dental Implant in Dogs

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    There are many obstacles to overcome in implant dentistry. The bony defect around implant can be seen in immediate installation procedures. Following tooth extraction, however, a socket often presents dimensions that may be considerably greater than the dimensions of a conventional implant

    Experimental Study on the Acellular Demal Matrix Graft for the Root Coverage in Dog

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    Mucogingival surgery is a plastic surgical procedure designed to correct defects in the morphology, position, and dimensions of the gingiva surrounding the teeth. Many surgical techniques have been reported in mucogingival surgery. Since these procedures also include the soft tissue esthetic approach, the term periodontal plastic surgery has been proposed to be more appropriate.1 Root coverage is a procedure that falls with this definition, and it has attracted more interest than others

    Investigating Endocrine Disrupting Impacts of Nine Disinfection Byproducts on Human and Zebrafish Estrogen Receptor Alpha

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    Background: Disinfection byproducts (DBPs) cause endocrine disruption via estrogenic or anti-estrogenic effects on estrogen receptors. However, most studies have focused on human systems, with little experimental data being presented on aquatic biota. This study aimed to compare the effects of nine DBPs on zebrafish and human estrogen receptor alpha (zERα and hERα). Methods: In vitro enzyme response-based tests, including cytotoxicity and reporter gene assays, were performed. Additionally, statistical analysis and molecular docking studies were employed to compare ERα responses. Results: Iodoacetic acid (IAA), chloroacetonitrile (CAN), and bromoacetonitrile (BAN) showed robust estrogenic activity on hERα (maximal induction ratios of 108.7%, 50.3%, and 54.7%, respectively), while IAA strongly inhibited the estrogenic activity induced by 17β-estradiol (E2) in zERα (59.8% induction at the maximum concentration). Chloroacetamide (CAM) and bromoacetamide (BAM) also showed robust anti-estrogen effects in zERα (48.1% and 50.8% induction at the maximum concentration, respectively). These dissimilar endocrine disruption patterns were thoroughly assessed using Pearson correlation and distance-based analyses. Clear differences between the estrogenic responses of the two ERαs were observed, whereas no pattern of anti-estrogenic activities could be established. Some DBPs strongly induced estrogenic endocrine disruption as agonists of hERα, while others inhibited estrogenic activity as antagonists of zERα. Principal coordinate analysis (PCoA) showed similar correlation coefficients for estrogenic and anti-estrogenic responses. Reproducible results were obtained from computational analysis and the reporter gene assay. Conclusions: Overall, the effects of DBPs on both human and zebrafish highlight the importance of controlling their differences in responsiveness for estrogenic activities including the water quality monitoring and endocrine disruption, as DBPs have species-specific ligand-receptor interactions.Peer reviewe

    Hepatoprotective and Antioxidative Activities of Cornus officinalis against Acetaminophen-Induced Hepatotoxicity in Mice

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    The fruit of Cornus officinalis Sieb. et Zucc. is commonly prescribed in Asian countries as a tonic formula. In this study, the hepatoprotective effect of ethanolic extracts of the fruit of C. officinalis (ECO) was investigated in a mouse model of acetaminophen- (APAP-) induced liver injury. Pretreatment of mice with ECO (100, 250, and 500 mg/kg for 7 days) significantly prevented the APAP (200 mg/kg) induced hepatic damage as indicated by the serum marker enzymes (AST, ALT, and LDH). Parallel to these changes, ECO treatment also prevented APAP-induced oxidative stress in the mice liver by inhibiting lipid peroxidation (MDA) and restoring the levels of antioxidant enzymes (SOD, CAT, and HO-1) and glutathione. Liver injury and collagen accumulation were assessed using histological studies by hematoxylin and eosin staining. Our results indicate that ECO can prevent hepatic injuries associated with APAP-induced hepatotoxicity by preventing or alleviating oxidative stress

    The Effects of Gymnema sylvestre in High-Fat Diet-Induced Metabolic Disorders

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    This study used an integrated approach to investigate the effects of Gymnema sylvestre (GS) extract as a functional dietary supplement with a high-fat diet. This approach examined insulin resistance, the dysfunction of adipose tissue, and liver steatosis. Male C57BL/6J mice were fed a normal chow or high-fat diet (HFD) for the acute and chronic study, in addition to GS in different doses (100, 250 and 500 mg/kg body weight). Their body composition changes, serum lipid and glucose parameters, adipose and liver tissue histology, and gene expression were measured. It was found that GS significantly suppressed the increase of body weight, serum levels of lipid, insulin and leptin, and adipose tissue, and liver inflammation. GS also demonstrated hypoglycemic effects due to the amylase inhibition activity. Our results support the existence of a relationship between the HFD induced insulin resistance, adipose dysfunction and liver steatosis. In conclusion, GS works as a functional dietary supplement with preventative effects against metabolic disorder.

    Lymphocyte-monocyte ratio at day 14 of first cisplatin-doxorubicin chemotherapy is associated with treatment outcome of pediatric patients with localized osteosarcoma

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    Purpose We aimed to determine the prognostic significance of lymphocyte counts and the lymphocytemonocyte ratio (LMR) in pediatric patients with osteosarcoma. Methods We retrospectively reviewed the medical records of 27 pediatric patients with localized extremity osteosarcoma, treated at the Korea Cancer Center Hospital between May 2002 and March 2016. Leukocyte counts and LMR before treatment and on day 14 (LMR14) of the first cisplatin-doxorubicin chemotherapy round were evaluated. Patients were dichotomized according to the median value of these parameters, and survival rates were compared. Results The median age of the 27 patients was 9.9 years (range, 3.2–14.1 years) and tumor sites were: distal femur (n=14), proximal humerus (n=7), proximal tibia (n=2), proximal fibula (n=2), and elsewhere (n=2). Patients were followed up on for a median of 76.4 months (range, 4.5–174.7 months), and 5-year overall (OS) and event-free survival (EFS) rates were 66.0%±9.8% and 60.9%±9.7%, respectively. Patients with a higher pretreatment lymphocyte count (≥2,320/μL) had better OS (90.9% vs. 46.2%, P=0.04) and EFS (83.9% vs. 38.5%, P=0.02). However, the day 14 lymphocyte count was not associated with survival. While no survival difference was observed between patients grouped according to pretreatment LMR (median value, 6.3), patients with a higher LMR14 (≥5) fared better than those with lower LMR14 (5-year OS: 83.3% vs. 46.3%, P=0.04). Conclusion Pretreatment lymphocyte count and LMR during chemotherapy had prognostic significance in pediatric osteosarcoma patients. Further studies involving larger cohorts are necessary to validate our findings

    Exploring the Association between Thyroid Function and Frailty: Insights from Representative Korean Data

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    Background This study investigates the association between thyroid function and frailty in the old patients using representative data. Methods The study was conducted using data from the Korea National Health and Nutrition Examination Survey conducted from 2013 to 2015. The study population included 2,416 participants aged 50 years and older with available thyroid function test data. Frailty assessment was performed using the Fried frailty phenotype. The prevalence of frailty was analyzed across different thyroid diseases and thyroid function parameters. Results The significant association between thyroid dysfunction and frailty was observed in overt hyperthyroidism and subclinical hyperthyroidism. After adjusting for various factors, the association between thyroid dysfunction and frailty remained significant. On the other hand, overt hypothyroidism did not show a significant association with frailty in the adjusted analysis. For individuals with overt hyperthyroidism and subclinical hyperthyroidism, higher levels of free thyroxine (FT4) were significantly associated with an increased risk of frailty (aOR >999; 95% CI, >999 to 999). Among individuals with overt hypothyroidism, lower level of FT4 levels and high thyrotropin (TSH) levels showed a significant association with frailty risk (FT4: aOR, <0.01; TSH: aOR, 999). In participants with subclinical hypothyroidism, there were no significant associations between parameters for thyroid and frailty risk. Conclusion These findings suggest that thyroid dysfunction, particularly overt hyperthyroidism and subclinical hyperthyroidism, may be associated with an increased risk of frailty in the old patients
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