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1.
J Korean Med Sci ; 39(20): e169, 2024 May 27.
Article in English | MEDLINE | ID: mdl-38804013

ABSTRACT

BACKGROUND: This research article investigates the age, period, and birth cohort effects on prevalence of obesity in the Korean population, with the goal of identifying key factors to inform effective public health strategies. METHODS: We analyzed data from the Korea National Health and Nutrition Examination Survey, spanning 2007-2021, including 35,736 men and 46,756 women. Using the hierarchical age-period-cohort (APC) analysis with cross-classified random effects modeling, we applied multivariable mixed logistic regression to estimate the marginal prevalence of obesity across age, period, and birth cohort, while assessing the interaction between APC and lifestyle and socioeconomic factors. RESULTS: Our findings reveal an inverted U-shaped age effect on obesity, influenced by smoking history (P for interaction = 0.020) and physical activity (I for interaction < 0.001). The period effect was positive in 2020 and 2021, while negative in 2014 (P for period effect < 0.001). A declining trend in obesity prevalence was observed in birth cohorts from 1980s onward. Notably, disparities in obesity rates among recent birth cohorts have increased in relation to smoking history (P for interaction = 0.020), physical activity (P for interaction < 0.001), and residence (P for interaction = 0.005). Particularly, those born after 1960 were more likely to be obese if they were ex-smokers, physical inactive, or lived in rural areas. CONCLUSION: These findings highlight growing disparities in obesity within birth cohorts, underscoring the need for targeted health policies that promote smoking cessation and physical activity, especially in rural areas.


Subject(s)
Nutrition Surveys , Obesity , Humans , Republic of Korea/epidemiology , Male , Obesity/epidemiology , Female , Middle Aged , Adult , Prevalence , Aged , Cohort Studies , Socioeconomic Factors , Smoking/epidemiology , Exercise , Logistic Models , Age Factors , Life Style , Young Adult
2.
J Korean Med Sci ; 38(2): e19, 2023 Jan 09.
Article in English | MEDLINE | ID: mdl-36625175

ABSTRACT

BACKGROUND: We investigated the extent of regional disparity of recurrent falls. In addition, we examined the association between particulate matter (PM) and recurrent falls and the association between regional disparity of recurrent falls and regional PM levels. METHOD: We used data from Korea Community Health Survey 2019 that included 204,395 participants from 237 municipal districts. The independent variables were the annual average PM10 and PM2.5 concentrations measured at the air quality measuring stations in each municipal district. The outcome variable was the experience of falls more than twice in the previous year. Multilevel analyses were conducted to estimate the association between regional PM10 and PM2.5 levels and recurrent falls. RESULTS: The regional variation was greater in the young people than that in the older people. PM10 and PM2.5 levels were positively associated with recurrent falls after adjusting for individual and regional covariates. These associations were more evident in the older group than in the young. PM10 and PM2.5 explained 2.82% and 3.33% of the remaining regional variance in models with individual and regional confounders, respectively. These proportions were greater in the older group (PM10 and PM2.5; 4.73% and 5.27%) than those in the younger age group (PM10 and PM2.5, 0.80% and 1.39%). CONCLUSION: PM concentration was associated with recurrent falls even after accounting for other regional variables and individual-level differences. Moreover, there were regional differences in the occurrence of falls, and the PM concentration explained a part of the gap, but the gap was explained more in the older group than in the young.


Subject(s)
Air Pollutants , Air Pollution , Humans , Aged , Adolescent , Particulate Matter/analysis , Air Pollutants/analysis , Environmental Exposure , Air Pollution/analysis , Republic of Korea
3.
BMC Cancer ; 21(1): 254, 2021 Mar 09.
Article in English | MEDLINE | ID: mdl-33750341

ABSTRACT

BACKGROUND: Alcohol consumption is a major risk factor for esophageal cancer; however, a high incidence of esophageal cancer is observed particularly among Eastern Asians, although they consume relatively less alcohol, presumably due to the high frequency of aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphisms. Nevertheless, the association between ALDH2 polymorphisms and esophageal cancer remains under debate. In the present study, we evaluated the association between ALDH2 rs671 polymorphisms and the risk of esophageal cancer in the South Korean population. METHODS: This study included 783 hospital based-cases and 8732 population-based controls. Information on smoking history and alcohol consumption was obtained from the medical records or interview questionnaires. Age-adjusted logistic regression analysis was performed to assess the association between ALDH2 rs671 polymorphisms and esophageal cancer. RESULTS: Odds ratios (ORs) for esophageal cancer in men with GA and AA genotypes were 2.75 (95% confidence interval [CI]: 2.34-3.23) and 0.08 (95% CI: 0.00-0.35), respectively; whereas, in women, these ratios were 2.99 (95% CI: 1.43-6.34) and 6.18 (95% CI: 1.40-19.62), respectively, taking subjects with the ALDH2 GG genotype as a reference. In men, the association between ALDH2 polymorphisms and esophageal cancer was modified by alcohol consumption. CONCLUSION: In Eastern Asians, ALDH2 rs671 polymorphisms are associated with esophageal cancer, which may be linked to acetaldehyde accumulation.


Subject(s)
Aldehyde Dehydrogenase, Mitochondrial/genetics , Esophageal Neoplasms/genetics , Genetic Predisposition to Disease , Polymorphism, Genetic , Aged , Case-Control Studies , Esophageal Neoplasms/etiology , Female , Genotype , Humans , Male , Middle Aged , Risk
4.
J Gastroenterol Hepatol ; 36(8): 2315-2323, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33604986

ABSTRACT

BACKGROUND AND AIM: While recent evidences support endoscopic resection as curative in ampullary tumors with high-grade intraepithelial neoplasia, only small case series have reported endoscopic management of early-stage ampullary cancer; thus, radical surgery remains the only accepted treatment modality. We evaluated the long-term outcomes of early ampullary adenocarcinoma administered endoscopic management. METHODS: We retrospectively reviewed electronic medical records of 715 patients undergoing endoscopic papillectomy (EP) in a single tertiary medical center in Korea in 2004-2016. We included patients incidentally diagnosed with early-stage adenocarcinoma (Tis and T1a, American Joint Committee on Cancer 8th edition) after EP and with >2 years of follow-up data and analyzed their demographics, histopathologic data, and clinical outcomes. RESULTS: Among 70 total patients in the EP-alone (n = 42) and subsequent surgery (n = 28) groups, we observed no significant differences in demographics or tumor size (2.0 ± 0.6 vs 1.9 ± 0.5 cm, P = 0.532), histologic grade (P = 0.077), tumor extent (P = 1.000), lymphovascular invasion (2.4% vs 10.7%, P = 0.344), or complete resection rates (57.1% vs 57.1%, P = 1.000) between groups. Adenocarcinoma lesions were larger in the subsequent surgery group (0.7 ± 0.5 vs 1.1 ± 0.7 cm, P = 0.002). The EP-alone group received more additional ablative treatment (42.9% vs 14.3%, P = 0.024). The 5-year disease-free and cancer-free survival rates were 79.1% vs 87.4% (P = 0.111) and 93.5% versus 87.4% (P = 0.726), respectively, and did not differ significantly between groups. CONCLUSIONS: Endoscopic papillectomy followed by endoscopic surveillance showed long-term outcomes comparable with surgical resection for early ampullary cancer and maybe curable alternative to surgery for incidentally found early-stage ampullary cancer, especially in patients unfit for or refusing radical surgery.


Subject(s)
Adenocarcinoma , Adenoma , Ampulla of Vater , Adenocarcinoma/surgery , Adenoma/surgery , Ampulla of Vater/surgery , Common Bile Duct Neoplasms/surgery , Duodenal Neoplasms/surgery , Humans , Retrospective Studies , Sphincterotomy, Endoscopic , Treatment Outcome
5.
Exp Dermatol ; 28(6): 734-737, 2019 06.
Article in English | MEDLINE | ID: mdl-30554432

ABSTRACT

Tyrosinase is a key enzyme that catalyses the initial rate-limiting steps of melanin synthesis. Due to its critical role in melanogenesis, various attempts were made to find potent tyrosinase inhibitors although many were not safe and effective in vivo. We evaluated tyrosinase inhibitory activity of six compounds. Among them, (Z)-5-(3-hydroxy-4-methoxybenzylidene)-2-thioxothiazolidin-4-one (5-HMT) had the greatest inhibitory effect and potency as the IC50 value of 5-HMT was lower than that of kojic acid, widely-known tyrosinase inhibitor. Based on in silico docking simulation, 5-HMT had a greater binding affinity than kojic acid with a different binding conformation in the tyrosinase catalytic site. Furthermore, its skin depigmentation effect was confirmed in vivo as 5-HMT topical treatment significantly reduced UVB-induced melanogenesis in HRM2 hairless mice. In conclusion, our study demonstrated that 5-HMT has a greater binding affinity and inhibitory effect on tyrosinase and may be a potential candidate for a therapeutic agent for preventing melanogenesis.


Subject(s)
Enzyme Inhibitors/pharmacology , Melanins/chemistry , Melanocytes/cytology , Monophenol Monooxygenase/antagonists & inhibitors , Animals , Drug Design , Inhibitory Concentration 50 , Mice , Molecular Docking Simulation , Pyrones/pharmacology , Skin Pigmentation , Thiazolidines/pharmacology , Ultraviolet Rays
6.
Bioorg Med Chem ; 27(11): 2192-2200, 2019 06 01.
Article in English | MEDLINE | ID: mdl-31027707

ABSTRACT

During our continued search for strong skin whitening agents over the past ten years, we have investigated the efficacies of many tyrosinase inhibitors containing a common (E)-ß-phenyl-α,ß-unsaturated carbonyl scaffold, which we found to be essential for the effective inhibition of mushroom and mammalian tyrosinases. In this study, we explored the tyrosinase inhibitory effects of 2,3-diphenylacrylic acid (2,3-DPA) derivatives, which also possess the (E)-ß-phenyl-α,ß-unsaturated carbonyl motif. We synthesized fourteen (E)-2,3-DPA derivatives 1a-1n and one (Z)-2,3-DPA-derivative 1l' using a Perkin reaction with phenylacetic acid and appropriate substituted benzaldehydes. In our mushroom tyrosinase assay, 1c showed higher tyrosinase inhibitory activity (76.43 ±â€¯3.53%, IC50 = 20.04 ±â€¯1.91 µM) with than the other 2,3-DPA derivatives or kojic acid (21.56 ±â€¯2.93%, IC50 = 30.64 ±â€¯1.27 µM). Our mushroom tyrosinase inhibitory results were supported by our docking study, which showed compound 1c (-7.2 kcal/mole) exhibited stronger binding affinity for mushroom tyrosinase than kojic acid (-5.7 kcal/mole). In B16F10 melanoma cells (a murine cell-line), 1c showed no cytotoxic effect up to a concentration of 25 µM and exhibited greater tyrosinase inhibitory activity (68.83%) than kojic acid (49.39%). In these cells, arbutin (a well-known tyrosinase inhibitor used as the positive control) only inhibited tyrosinase by 42.67% even at a concentration of 400 µM. Furthermore, at 25 µM, 1c reduced melanin contents in B16F10 melanoma cells by 24.3% more than kojic acid (62.77% vs. 38.52%). These results indicate 1c is a promising candidate treatment for pigmentation-related diseases and potential skin whitening agents.


Subject(s)
Cinnamates/pharmacology , Enzyme Inhibitors/pharmacology , Free Radical Scavengers/pharmacology , Skin Lightening Preparations/pharmacology , Stilbenes/pharmacology , Agaricus/enzymology , Animals , Catalytic Domain , Cell Line, Tumor , Cinnamates/chemical synthesis , Cinnamates/metabolism , Cinnamates/toxicity , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/metabolism , Enzyme Inhibitors/toxicity , Free Radical Scavengers/chemical synthesis , Free Radical Scavengers/metabolism , Free Radical Scavengers/toxicity , Mice , Molecular Docking Simulation , Monophenol Monooxygenase/chemistry , Monophenol Monooxygenase/metabolism , Protein Binding , Pyrones/chemistry , Pyrones/metabolism , Skin Lightening Preparations/chemical synthesis , Skin Lightening Preparations/metabolism , Skin Lightening Preparations/toxicity , Stilbenes/chemical synthesis , Stilbenes/metabolism , Stilbenes/toxicity
7.
Bioorg Med Chem ; 27(17): 3929-3937, 2019 09 01.
Article in English | MEDLINE | ID: mdl-31345746

ABSTRACT

Targeting of tyrosinase has proven to be the best means of identifying safe, efficacious, and potent tyrosinase inhibitors for whitening skin. We designed and synthesized ten NAB (N-(acryloyl)benzamide) derivatives (1a-1j) using the Horner-Wadsworth-Emmons olefination of diethyl (2-benzamido-2-oxoethyl)phosphonate and appropriate benzaldehydes. A mushroom tyrosinase inhibitory assay showed compounds 1a (36.71 ±â€¯2.14% inhibition) and 1j (25.99 ±â€¯2.77% inhibition) inhibited tyrosinase more than the other eight NAB derivatives and kojic acid (21.56 ±â€¯2.93% inhibition), and docking studies indicated 1a (-6.9 kcal/mole) and 1j (-7.5 kcal/mole) had stronger binding affinities for tyrosinase than kojic acid (-5.7 kcal/mole). At a concentration of 25 µM, 1a and 1j were nontoxic in B16F10 melanoma cells and exhibited stronger tyrosinase inhibition (59.70% and 76.77%, respectively) than kojic acid (50.30% inhibition) or arbutin (41.78% inhibition at 400 µM). Similarly, in B16F10 melanoma cells, compounds 1a and 1j at 25 µM decreased total melanin content by 47.97% and 61.77%, respectively (kojic acid; 38.98%). Similarities between inhibitions of tyrosinase activity and melanin contents suggested the anti-melanogenic effects of 1a and 1j were due to tyrosinase inhibition. The excellent DPPH scavenging activity of 1j suggests it might enhance in vivo effect on melanin contents. The study suggests compound 1j offers a potential starting point for the development of safe, potent tyrosinase inhibitors.


Subject(s)
Benzamides/pharmacology , Enzyme Inhibitors/pharmacology , Free Radical Scavengers/pharmacology , Melanins/antagonists & inhibitors , Monophenol Monooxygenase/antagonists & inhibitors , Agaricales/enzymology , Animals , Benzamides/chemical synthesis , Benzamides/chemistry , Biphenyl Compounds/antagonists & inhibitors , Cell Survival , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Free Radical Scavengers/chemical synthesis , Free Radical Scavengers/chemistry , Melanins/metabolism , Mice , Molecular Structure , Monophenol Monooxygenase/metabolism , Picrates/antagonists & inhibitors , Structure-Activity Relationship , Tumor Cells, Cultured
8.
Bioorg Chem ; 87: 43-55, 2019 06.
Article in English | MEDLINE | ID: mdl-30856375

ABSTRACT

Abnormal melanogenesis results in excessive production of melanin, leading to pigmentation disorders. As a key and rate-limiting enzyme for melanogenesis, tyrosinase has been considered an important target for developing therapeutic agents of pigment disorders. Despite having an (E)-ß-phenyl-α,ß-unsaturated carbonyl scaffold, which plays an important role in the potent inhibition of tyrosinase activity, cinnamic acids have not attracted attention as potential tyrosinase inhibitors, due to their low tyrosinase inhibitory activity and relatively high hydrophilicity. Given that cinnamic acids' structure intrinsically features this (E)-scaffold and following our experience that minute changes in the chemical structure can powerfully affect tyrosinase activity, twenty less hydrophilic cinnamamide derivatives were designed as potential tyrosinase inhibitors and synthesised using a Horner-Wadsworth-Emmons reaction. Four of these cinnmamides (4, 9, 14, and 19) exhibited much stronger mushroom tyrosinase inhibition (over 90% inhibition) at 25 µM compared to kojic acid (20.57% inhibition); crucially, all four have a 2,4-dihydroxy group on the ß-phenyl ring of the scaffold. A docking simulation using tyrosinase indicated that the four cinnamamides exceeded the binding affinity of kojic acid, and bound more strongly to the active site of tyrosinase. Based on the strength of their tyrosinase inhibition, these four cinnamamides were further evaluated in B16F10 melanoma cells. All four cinnamamides, without cytotoxicity, exhibited higher tyrosinase inhibitory activity (67.33 - 79.67% inhibition) at 25 µM than kojic acid (38.11% inhibition), with the following increasing inhibitory order: morpholino (9) = cyclopentylamino (14) < cyclohexylamino (19) < N-methylpiperazino (4) cinnamamides. Analysis of tyrosinase activity and melanin content in B16F10 cells showed that the four cinnamamides dose-dependently inhibited both cellular tyrosinase activity and melanin content and that their inhibitory activity at 25 µM was much better than that of kojic acid. The results of melanin content analysis well matched those of the cellular tyrosinase activity analysis, indicating that tyrosinase inhibition by the four cinnamamides is a major factor in the reduction of melanin production. These results imply that these four cinnamamides with a 2,4-dihydroxyphenyl group can act as excellent anti-melanogenic agents in the treatment of pigmentation disorders.


Subject(s)
Cinnamates/pharmacology , Enzyme Inhibitors/pharmacology , Melanins/antagonists & inhibitors , Monophenol Monooxygenase/antagonists & inhibitors , Animals , Cell Survival/drug effects , Cinnamates/chemical synthesis , Cinnamates/chemistry , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Melanins/biosynthesis , Mice , Molecular Docking Simulation , Molecular Structure , Monophenol Monooxygenase/metabolism , Structure-Activity Relationship , Tumor Cells, Cultured
9.
Bioorg Med Chem Lett ; 28(4): 684-688, 2018 02 15.
Article in English | MEDLINE | ID: mdl-29402742

ABSTRACT

The NAD+-dependent deacetylase SIRT1, which is associated with the improvement of metabolic syndromes, such as type 2 diabetes, is a well-known longevity-related gene. Several in vitro and in vivo studies have shown the known protective effects of SIRT1 activators, such as resveratrol and SRT1720, on diabetes- or obesity-induced fatty liver and insulin resistance. Here, we newly synthesized 18 benzoxazole hydrochloride derivatives based on the structure of resveratrol and SRT1720. We performed an in vitro SIRT1 activity assay to identify the strongest SIRT1 activator. The assay confirmed MHY2233 to be the strongest SIRT1 activator (1.5-fold more potent than resveratrol), and docking simulation showed that the binding affinity of MHY2233 was higher than that of resveratrol and SRT1720. To investigate its beneficial effects, db/db mice were orally administered MHY2233 for 1 month, and various metabolic parameters were assessed in the serum and liver tissues. MHY2233 markedly ameliorated insulin signaling without affecting body weight in db/db mice. In particular, the mRNA expression of lipogenic genes, such as acetyl CoA carboxylase, fatty acid synthase, and sterol regulatory element-binding protein, which increased in db/db mice, decreased following oral treatment with MHY2233. In conclusion, the novel SIRT1 activator MHY2233 reduced lipid accumulation and improved insulin resistance. This finding may contribute toward therapeutic approaches for fatty liver disease and glucose tolerance.


Subject(s)
Benzoxazoles/pharmacology , Enzyme Activators/pharmacology , Fatty Liver/drug therapy , Glucose Intolerance/drug therapy , Sirtuin 1/metabolism , Acetyl-CoA Carboxylase/genetics , Animals , Benzoxazoles/administration & dosage , Benzoxazoles/chemical synthesis , Body Weight , Diabetes Mellitus/drug therapy , Enzyme Activators/administration & dosage , Enzyme Activators/chemical synthesis , Fatty Acid Synthases/genetics , Gene Expression Regulation/drug effects , Heterocyclic Compounds, 4 or More Rings/chemistry , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/chemical synthesis , Hypoglycemic Agents/pharmacology , Male , Metabolic Syndrome/drug therapy , Mice, Inbred C57BL , Molecular Docking Simulation , Resveratrol , Sterol Regulatory Element Binding Proteins/genetics , Stilbenes/chemistry , Stilbenes/pharmacology
10.
Bioorg Med Chem ; 26(21): 5672-5681, 2018 11 15.
Article in English | MEDLINE | ID: mdl-30366788

ABSTRACT

Pigmentation disorders are attributed to excessive melanin which can be produced by tyrosinase. Therefore, tyrosinase is supposed to be a vital target for the treatment of disorders associated with overpigmentation. Based on our previous findings that an (E)-ß-phenyl-α,ß-unsaturated carbonyl scaffold can play a key role in the inhibition of tyrosinase activity, and the fact that cinnamic acid is a safe natural substance with a scaffolded structure, it was speculated that appropriate cinnamic acid derivatives may exhibit potent tyrosinase inhibitory activity. Thus, ten cinnamamides were designed, and synthesized by using a Horner-Emmons olefination as the key step. Cinnamamides 4 (93.72% inhibition), 9 (78.97% inhibition), and 10 (59.09% inhibition) with either a 2,4-dihydroxyphenyl, or 4-hydroxy-3-methoxyphenyl substituent showed much higher mushroom tyrosinase inhibition at 25 µM than kojic acid (18.81% inhibition), used as a positive control. Especially, the two cinnamamides 4 and 9 having a 2,4-dihydroxyphenyl group showed the strongest inhibition. Docking simulation with tyrosinase revealed that these three cinnamamides, 4, 9, and 10, bind to the active site of tyrosinase more strongly than kojic acid. Cell-based experiments carried out using B16F10 murine skin melanoma cells demonstrated that all three cinnamamides effectively inhibited cellular tyrosinase activity and melanin production in the cells without cytotoxicity. There was a close correlation between cellular tyrosinase activity and melanin content, indicating that the inhibitory effect of the three cinnamamides on melanin production is mainly attributed to their capability for cellular tyrosinase inhibition. These results imply that cinnamamides having the (E)-ß-phenyl-α,ß-unsaturated carbonyl scaffolds are promising candidates for skin-lighting agents.


Subject(s)
Amides/pharmacology , Cinnamates/pharmacology , Enzyme Inhibitors/pharmacology , Melanins/antagonists & inhibitors , Skin Lightening Preparations/pharmacology , Agaricales/enzymology , Amides/chemical synthesis , Amides/chemistry , Amides/toxicity , Animals , Cell Line, Tumor , Cinnamates/chemical synthesis , Cinnamates/chemistry , Cinnamates/toxicity , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/toxicity , Free Radical Scavengers/chemical synthesis , Free Radical Scavengers/chemistry , Free Radical Scavengers/pharmacology , Free Radical Scavengers/toxicity , Mice , Molecular Docking Simulation , Molecular Structure , Monophenol Monooxygenase/antagonists & inhibitors , Monophenol Monooxygenase/chemistry , Pyrones/chemistry , Skin Lightening Preparations/chemical synthesis , Skin Lightening Preparations/chemistry , Skin Lightening Preparations/toxicity , Structure-Activity Relationship
11.
Bioorg Med Chem ; 26(14): 3882-3889, 2018 08 07.
Article in English | MEDLINE | ID: mdl-29907470

ABSTRACT

Thirteen (Z)-4-(substituted benzylidene)-3-phenylisoxazol-5(4H)-ones were designed to confirm the geometric effect of the double bond of the ß-phenyl-α, ß-unsaturated carbonyl scaffold on tyrosinase inhibitory activity. Compounds 1a-1m, which all possessed the (Z)-ß-phenyl-α, ß-unsaturated carbonyl scaffold, were synthesized using a tandem reaction consisting of an isoxazolone ring formation and a Knoevenagel condensation, and three starting materials, ethyl benzoylacetate, hydroxylamine and benzaldehydes. Some of the compounds showed inhibitory activity against mushroom tyrosinase as potent as compounds containing the "(E)"-ß-phenyl-α, ß-unsaturated carbonyl scaffold. Compounds 1c and 1m showed greater inhibitory activity than kojic acid: IC50 = 32.08 ±â€¯2.25 µM for 1c; IC50 = 14.62 ±â€¯1.38 µM for 1m; and IC50 = 37.86 ±â€¯2.21 µM for kojic acid. A kinetic study indicated that 1m inhibited tyrosinase in a competitive manner and that it probably binds to the enzyme's active site. In silico docking simulation supported binding of 1m (-7.6 kcal/mol) to the active site of tyrosinase with stronger affinity than kojic acid (-5.7 kcal/mol). Similar results were obtained using cell-based assays, and in B16F10 cells, compound 1m dose-dependently inhibited tyrosinase activity and melanogenesis. These results indicate the anti-melanogenic effect of compound 1m is due to the inhibition of tyrosinase and (Z)-isomer of the ß-phenyl-α, ß-unsaturated carbonyl scaffold can, like its congener the (E)-isomer, act as an excellent scaffold for tyrosinase inhibition.


Subject(s)
Enzyme Inhibitors/pharmacology , Monophenol Monooxygenase/antagonists & inhibitors , Oxazolone/pharmacology , Agaricales/enzymology , Animals , Cell Survival/drug effects , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Kinetics , Mice , Molecular Docking Simulation , Molecular Structure , Monophenol Monooxygenase/metabolism , Oxazolone/chemical synthesis , Oxazolone/chemistry , Structure-Activity Relationship , Tumor Cells, Cultured
12.
Biosci Biotechnol Biochem ; : 1-9, 2018 Mar 09.
Article in English | MEDLINE | ID: mdl-29521165

ABSTRACT

As part of continued efforts for the development of new tyrosinase inhibitors, (Z)-5-(substituted benzylidene)-2-iminothiazolidin-4-one derivatives (1a - 1l) were rationally synthesized and evaluated for their inhibitory potential in vitro. These compounds were designed and synthesized based on the structural attributes of a ß-phenyl-α,ß-unsaturated carbonyl scaffold template. Among these compounds, (Z)-5-(3-hydroxy-4-methoxybenzylidene)-2-iminothiazolidin-4-one (1e, MHY773) exhibited the greatest tyrosinase inhibition (IC50 = 2.87 µM and 8.06 µM for monophenolase and diphenolase), and outperformed the positive control, kojic acid (IC50 = 15.59 and 31.61 µM). The kinetic and docking studies demonstrated that MHY773 interacted with active site of tyrosinase. Moreover, a melanin quantification assay demonstrated that MHY773 attenuates α-melanocyte-stimulating hormone (α-MSH) and 3-isobutyl-1-methylxanthine (IBMX)-induced melanin contents in B16F10 melanoma cells. Taken together, these data suggest that MHY773 suppressed the melanin production via the inhibition of tyrosinase activity. MHY773 is a promising for the development of effective pharmacological and cosmetic agents for skin-whitening.

13.
Pathobiology ; 84(3): 130-138, 2017.
Article in English | MEDLINE | ID: mdl-28288473

ABSTRACT

BACKGROUND: Smad4 and GATA3 proteins are known prognostic markers in various cancers. Smad4 is a mediator linked to both tumour suppression and progression. GATA3 is a regulator of development and morphogenesis of the mammary gland. We assessed and compared the predictive performance of Smad4 and GATA3 for clinical outcomes in patients with breast cancer. METHODS: The combined expression pattern based on Smad4+/- and GATA3+/- was evaluated by immunostaining using breast cancer tissue microarray, and the relationships between protein expression and clinicopathological variables were analysed. RESULTS: Smad4 expression was only associated with an ill-defined tumour border, whereas GATA3 was associated with several good prognostic factors. On analysis of combined markers, there was a significant difference in the expression of fascin (an important factor for cancer invasiveness) between the Smad4+/GATA3- and Smad4-/GATA3+ groups. Smad4+/GATA3- was correlated with worse clinicopathological parameters, relapse-free survival (RFS), and overall survival (OS), compared to Smad4-/GATA3+. CONCLUSION: Combined markers of Smad4/GATA3 showed a superior performance compared to single markers for predicting RFS and OS in patients with breast cancer.


Subject(s)
Biomarkers, Tumor/metabolism , Breast Neoplasms/metabolism , Carcinoma, Ductal, Breast/metabolism , GATA3 Transcription Factor/metabolism , Gene Expression Regulation, Neoplastic , Smad4 Protein/metabolism , Breast Neoplasms/pathology , Carcinoma, Ductal, Breast/pathology , Disease-Free Survival , Female , Humans , Middle Aged , Prognosis , Tissue Array Analysis
14.
Tumour Biol ; 37(3): 3359-64, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26446458

ABSTRACT

Cell cycle regulatory proteins including p16, p27, and p53 are well studied in various cancers. However, their single or concurrent roles related with the clinicopathological parameters are not clearly recognized. We analyzed the expression of p16, p27, and p53 cell cycle regulatory proteins in papillary thyroid carcinoma (PTC). To determine the prognostic significance of cell cycle regulatory proteins, 107 PTCs were examined. We analyzed the individual expression of p16, p27, and p53 and their concurrent expressions, with the relationship to various clinicopathological parameters including differentiation from benign lesions. High expression of p16 and p53 and low expression of p27 were related with the distinguishing of PTC from benign lesions. In addition, normal thyroidal tissue showed higher p27 expression than nodular hyperplasia. In relation to extrathyroidal extension (ETE), the low expression of p27 was related with the presence of ETE. The low expression of p27 and high expression of p16 and p53 may affect the development of PTC. In addition, low p27 expression is related with the existence of ETE.


Subject(s)
Carcinoma, Papillary/metabolism , Cell Transformation, Neoplastic/metabolism , Cyclin-Dependent Kinase Inhibitor p16/biosynthesis , Cyclin-Dependent Kinase Inhibitor p27/biosynthesis , Thyroid Neoplasms/metabolism , Tumor Suppressor Protein p53/biosynthesis , Adult , Aged , Carcinoma, Papillary/pathology , Cell Transformation, Neoplastic/pathology , Female , Humans , Immunohistochemistry , Male , Middle Aged , Neoplasm Invasiveness , Prognosis , Thyroid Neoplasms/pathology , Tissue Array Analysis , Young Adult
15.
PLoS One ; 19(2): e0296682, 2024.
Article in English | MEDLINE | ID: mdl-38335189

ABSTRACT

Longitudinal research has provided systematic empirical data on the short- and long-term outcomes of admissions policies, curricular innovations, and complex decisions on students' academic progress. This study aimed to investigate the academic performance of medical students and related factors using cohort database collected from a medical school. The study participants included 134 medical students who graduated from Chonnam National University Medical School in 2022. The medical school's cohort database was used to collect data on demographics, admission, academic performance, extracurricular activities, and performance on the National Korean Medical Licensing Examination (KMLE). Participating in club activities had a significant association with medical students' academic advancement delay or leave of absence during the entire course of medical school (P = 0.007). Logistic regression analysis indicated that the nationwide clinical knowledge mock examination during the fourth year of medical school was significantly associated with passing the KMLE (adjusted odds ratio 1.12, 95% confidence interval 1.02-1.22; P = 0.014). Extracurricular school activities (a non-cognitive student attribute) and a wide range of cognitive student attributes captured from the cohort database were associated with medical students' academic performance. In conclusion, this study can reinforce a strong emphasis on the inclusion of cognitive and non-cognitive information in medical school curricula and assessments in order to improve medical education programs and future postgraduate performance.


Subject(s)
Academic Performance , Students, Medical , Humans , Retrospective Studies , Students, Medical/psychology , Schools, Medical , Universities
16.
Korean Circ J ; 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-39175343

ABSTRACT

BACKGROUND AND OBJECTIVES: Familial hypercholesterolemia (FH) increases the risk of premature cardiovascular disease through disrupted low-density lipoprotein cholesterol (LDL-C) metabolism. Although FH is a severe condition, it remains widely underdiagnosed, which can be attributed to barriers in genetic testing and a lack of awareness. This study aims to propose and evaluate a targeted screening program for FH in South Korea by integrating the General Health Screening Program (GHSP) with cascade genetic screening. METHODS: The study included individuals with LDL-C levels ≥190 mg/dL identified during the 2021 GHSP (primary participants). Data on demographics, lifestyle, medical history, and family history were collected through questionnaires. Targeted next-generation sequencing was used to identify pathogenic mutations in the PCSK9, APOB, LDLRAP1, and LDLR genes associated with FH. Pathogenic mutations found in primary participants were confirmed in their relatives (secondary participants) using Sanger sequencing. Participant characteristics were analyzed based on the presence of pathogenic mutations. RESULTS: Among 83 individuals with severe hypercholesterolemia identified through the GHSP, 7 primary participants (8.4%) carried pathogenic mutations in the LDLR and PCSK9 genes. In secondary participants, pathogenic mutations were identified in 61.1% of the relatives of 4 patients with pathogenic mutations. The prevalence of pathogenic mutations was significantly higher in primary participants compared to secondary participants. CONCLUSIONS: Integrating community resources with FH screening can enhance the early detection and treatment of FH. By utilizing GHSP data and adding genetic screening, the proposed model provides a strategy to reduce the cardiovascular risks associated with FH, supporting its wider adoption at the national level.

17.
Epidemiol Health ; 45: e2023039, 2023.
Article in English | MEDLINE | ID: mdl-36996866

ABSTRACT

OBJECTIVES: Elevated C-reactive protein (CRP) levels are associated with an increased risk for colorectal cancer (CRC), as well as a poor prognosis, but it remains unclear whether these associations are causal. This study examined the potential causality between CRP levels and CRC survival using 2-sample Mendelian randomization (MR). METHODS: From the Korean Genome and Epidemiology Study, a genome-wide association study (n=59,605), 7 single-nucleotide polymorphisms (SNPs) related to log2-transformed CRP levels were extracted as instrumental variables for CRP levels. The associations between the genetically predicted CRP and CRC-specific and overall mortality among CRC patients (n=6,460) were evaluated by Aalen's additive hazard model. The sensitivity analysis excluded a SNP related to the blood lipid profile. RESULTS: During a median of 8.5 years of follow-up, among 6,460 CRC patients, 2,676 (41.4%) CRC patients died from all causes and 1,622 (25.1%) died from CRC. Genetically predicted CRP levels were not significantly associated with overall or CRC-specific mortality in CRC patients. The hazard difference per 1,000 person-years for overall and CRC-specific mortality per 2-fold increase in CRP levels was -2.92 (95% confidence interval [CI], -14.05 to 8.21) and -0.76 (95% CI, -9.61 to 8.08), respectively. These associations were consistent in a subgroup analysis according to metastasis and a sensitivity analysis excluding possible pleiotropic SNPs. CONCLUSIONS: Our findings do not support a causal role for genetically predisposed CRP levels in CRC survival.


Subject(s)
Colorectal Neoplasms , Mendelian Randomization Analysis , Humans , C-Reactive Protein/genetics , C-Reactive Protein/metabolism , Genome-Wide Association Study , Polymorphism, Single Nucleotide , Colorectal Neoplasms/genetics , Republic of Korea/epidemiology
18.
J Prev Med Public Health ; 56(3): 282-290, 2023 May.
Article in English | MEDLINE | ID: mdl-37287206

ABSTRACT

OBJECTIVES: This study aimed to evaluate the potential interaction between kidney function and the non-linear association between serum calcium levels and cardiovascular disease (CVD) mortality. METHODS: This study included 8927 participants enrolled in the Dong-gu Study. Albumin-corrected calcium levels were used and categorized into 6 percentile categories: <2.5th, 2.5-25.0th, 25.0-50.0th, 50.0-75.0th, 75.0-97.5th, and >97.5th. Restricted cubic spline analysis was used to examine the non-linear association between calcium levels and CVD mortality. Cox proportional hazard regression was used to estimate hazard ratios (HRs) for CVD mortality according to serum calcium categories. All survival analyses were stratified by the estimated glomerular filtration rate. RESULTS: Over a follow-up period of 11.9±2.8 years, 1757 participants died, of whom 219 died from CVD. A U-shaped association between serum calcium and CVD mortality was found, and the association was more evident in the low kidney function group. Compared to the 25.0-50.0th percentile group for serum calcium levels, both low and high serum calcium tended to be associated with CVD mortality (<2.5th: HR, 6.23; 95% confidence interval [CI], 1.16 to 33.56; >97.5th: HR, 2.56; 95% CI, 0.76 to 8.66) in the low kidney function group. In the normal kidney function group, a similar association was found between serum calcium levels and CVD mortality (<2.5th: HR, 1.37; 95% CI, 0.58 to 3.27; >97.5th: HR, 1.65; 95% CI, 0.70 to 3.93). CONCLUSIONS: We found a non-linear association between serum calcium levels and CVD mortality, suggesting that calcium dyshomeostasis may contribute to CVD mortality, and kidney function may modify the association.


Subject(s)
Calcium , Cardiovascular Diseases , Humans , Adult , Risk Factors , Kidney , Republic of Korea/epidemiology
19.
Korean Circ J ; 53(7): 472-479, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37271750

ABSTRACT

BACKGROUND AND OBJECTIVES: The association between bilirubin and atrial fibrillation (AF) has been evaluated previously in observational studies but with contradictory results. This study evaluated the causal association between serum bilirubin level and AF using Mendelian randomization (MR) analysis. METHODS: This cross-sectional study includes 8,977 participants from the Dong-gu Study. In the observational analysis, multivariate logistic regression was performed to evaluate the association between bilirubin and prevalent AF. To evaluate the causal association between bilirubin and AF, MR analysis was conducted by using the UGT1A1 rs11891311 and rs4148323 polymorphisms as instrumental variables. RESULTS: Elevated serum bilirubin levels were associated with an increased risk for AF in observational analysis (total bilirubin: odds ratio [OR], 1.31; 95% confidence interval [95% CI], 1.15-1.48 per 1 standard deviation [SD]; direct bilirubin: OR, 1.31; 95% CI, 1.18-1.46 per 1 SD), whereas the genetically predicted serum bilirubin levels in MR analysis did not show this association (total bilirubin: OR, 1.02; 95% CI, 0.67-1.53 per 1 SD; direct bilirubin: OR, 1.03; 95% CI, 0.61-1.73 per 1 SD). CONCLUSIONS: Genetically predicted bilirubin levels were not associated with prevalent AF. Thus, the observational association between serum bilirubin levels and AF may be non-causal and affected by reverse causality or unmeasured confounding.

20.
Article in English | MEDLINE | ID: mdl-36497856

ABSTRACT

Improved diabetes management in primary care is essential for reducing the public health burden of diabetes, and various programs are being implemented in Korea for this purpose. Although the Health Insurance Review and Assessment (HIRA) evaluates the quality of type 2 diabetes management in primary care clinics and hospitals, it is unclear whether the implementation of these evaluations is related to the adequate management of complications in diabetic patients. We evaluated the association between the proportion of clinics managing diabetes well and lifestyles and uptake of screening for complications in 24,620 diabetic participants of the 2019 Korean Community Health Survey (KCHS). Multivariate multilevel logistic regression was performed to evaluate the fixed effect of the district-level variable and the heterogeneity among districts. The proportion of clinics with good diabetes management per 10,000 inhabitants was positively related to screening for diabetes complications. Furthermore, this district variable was significantly related to engaging in walking activity (Odds ratio: 1.39, 95% CI: 1.10-1.76) and sufficiently explained the heterogeneity among districts. However, current smoking and weight control were not associated with the proportion of clinics with good diabetes management. The financial incentives to primary care clinics would improve the primary prevention of diabetic complications.


Subject(s)
Diabetes Complications , Diabetes Mellitus, Type 2 , Humans , Diabetes Mellitus, Type 2/epidemiology , Diabetes Mellitus, Type 2/therapy , Quality of Health Care , Surveys and Questionnaires , Odds Ratio
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