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1.
Evidence and suggestions for establishing vitamin D intake standards in Koreans for the prevention of chronic diseases.
Kim, JH, Park, HS, Pae, M, Park, KH, Kwon, O
Nutrition research and practice. 2022;(Suppl 1):S57-S69
Abstract
BACKGROUND/OBJECTIVES Vitamin D is produced in the skin during sun exposure and is also ingested from foods. The role of vitamin D needs to be considered in the prevention and management of various diseases. Moreover, since the majority of Koreans spend their days indoors, becoming susceptible to the risk of vitamin D deficiency. The current study aims to prepare a basis for determining dietary reference intake of vitamin D in Korea, by reviewing the evidence against various diseases and risks. MATERIALS/METHODS Literature published in Korea and other countries between 2014 and 2018 was prioritized based on their study design and other criteria, and evaluated using the RoB 2.0 assessment form and United States Department of Agriculture Nutrition Evidence Library Conclusion Statement Evaluation Criteria. RESULTS Of the 1,709 studies, 128 studies were included in the final systematic analysis after screening. To set the dietary reference intakes of vitamin D based on the selected articles, blood 25(OH)D levels and indicators of bone health were used collectively. Blood vitamin D levels and ultraviolet (UV) exposure time derived from the Korean National Health and Nutrition Examination Survey were analyzed to establish the dietary reference intakes of vitamin D for each stage of the life cycle. The adequate intake levels of vitamin D, according to age and gender, were determined to be in the range of 5-15 μg/day, and the tolerable upper intake level was established at 25-100 μg/day. CONCLUSIONS The most important variable for vitamin D nutrition is lifestyle. A balanced diet comprising foods with high contents of vitamin D is important, as is vitamin D synthesis after UV exposure. The adequate intake level of vitamin D mentioned in the 2015 Dietary Reference Intakes for Korean (KDRI) remained unchanged in the 2020 KDRI for the management of vitamin D nutrition in Koreans.
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2.
Bioactive Sphingolipids as Major Regulators of Coronary Artery Disease.
Song, JH, Kim, GT, Park, KH, Park, WJ, Park, TS
Biomolecules & therapeutics. 2021;(4):373-383
Abstract
Atherosclerosis is the deposition of plaque in the main arteries. It is an inflammatory condition involving the accumulation of macrophages and various lipids (low-density lipoprotein [LDL] cholesterol, ceramide, S1P). Moreover, endothelial cells, macrophages, leukocytes, and smooth muscle cells are the major players in the atherogenic process. Sphingolipids are now emerging as important regulators in various pathophysiological processes, including the atherogenic process. Various sphingolipids exist, such as the ceramides, ceramide-1-phosphate, sphingosine, sphinganine, sphingosine-1-phosphate (S1P), sphingomyelin, and hundreds of glycosphingolipids. Among these, ceramides, glycosphingolipids, and S1P play important roles in the atherogenic processes. The atherosclerotic plaque consists of higher amounts of ceramide, glycosphingolipids, and sphingomyelin. The inhibition of the de novo ceramide biosynthesis reduces the development of atherosclerosis. S1P regulates atherogenesis via binding to the S1P receptor (S1PR). Among the five S1PRs (S1PR1-5), S1PR1 and S1PR3 mainly exert anti-atherosclerotic properties. This review mainly focuses on the effects of ceramide and S1P via the S1PR in the development of atherosclerosis. Moreover, it discusses the recent findings and potential therapeutic implications in atherosclerosis.
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3.
Exogenous influences on intraocular pressure.
Kim, YW, Park, KH
The British journal of ophthalmology. 2019;(9):1209-1216
Abstract
Intraocular pressure (IOP), the pressure within the eyeball, is a function mainly of the production and elimination of aqueous humour. Balanced IOP helps to maintain the eyeball contour, allowing proper refraction of light in the anterior segment of the eye. Increases in IOP can cause injury to the ocular structure, typically the optic nerve head and retinal ganglion cells. IOP increase, additionally, is a risk factor for glaucoma progression. However, it is not unusual that glaucoma worsens despite well-managed IOP; indeed, glaucoma can develop and progress even within the normal IOP range. IOP measured once during daytime office hours might not provide sufficient information for effective glaucoma management. In fact, IOP is not a fixed value but rather changes over time: it fluctuates with the intrinsic circadian rhythm and can also change in various lifestyle-related situations (eg, with body posture, during exercise, while holding breath and according to dietary habits). It is therefore worth exploring the various factors that can affect IOP and glaucoma risk. In this review, the various exogenous influences on IOP in the literature are investigated.
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4.
Direct interspecies electron transfer via conductive materials: A perspective for anaerobic digestion applications.
Park, JH, Kang, HJ, Park, KH, Park, HD
Bioresource technology. 2018;:300-311
Abstract
Anaerobic digestion (AD) is a microbial process that produces renewable energy in the form of methane by treating organic waste and high-strength wastewater. Recent studies have demonstrated that conductive materials can promote direct interspecies electron transfer (DIET) between exoelectrogenic bacteria and methanogenic archaea. DIET via conductive materials is more effective for methane production than interspecies electron transfer using electron carriers such as hydrogen, a principal route of methane production in conventional AD. This critical review presents the current understanding of DIET via conductive materials for methane production, summarizes the relevant studies published to date, and analyzes these studies with regard to conductive materials, substrates, inocula, performance, and microorganisms. Based on this analysis, possible future directions are suggested for practical DIET applications via conductive materials in AD.
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5.
Diabetic macular oedema: evidence-based treatment recommendations for Asian countries.
Cheung, GC, Yoon, YH, Chen, LJ, Chen, SJ, George, TM, Lai, TY, Park, KH, Tahija, SG, Uy, HS, Wong, TY
Clinical & experimental ophthalmology. 2018;(1):75-86
Abstract
Diabetic macular oedema is the most common cause of diabetic retinopathy-induced vision loss. Efficacy of anti-vascular endothelial growth factor therapy in diabetic macular oedema has been demonstrated in randomized controlled trials. An Asian-specific guideline for diabetic macular oedema treatment is needed as patients in Asia tend to present with far more advanced disease than seen elsewhere in the world. Previous reviews of diabetic macular oedema management lacked a broader assessment of anti-vascular endothelial growth factor treatment choices and newer trials. Recent clinical trial data allow head-to-head comparisons between the different anti-vascular endothelial growth factor agents and treatment regimens. This review aims to summarize the clinical evidence related to various treatment regimens for clinicians, with a focus on anti-vascular endothelial growth factor therapies, and to provide guidance on the treatment of diabetic macular oedema in Asian patients.
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6.
An Overview of Ophthalmologic Survey Methodology in the 2008-2015 Korean National Health and Nutrition Examination Surveys.
Yoon, KC, Choi, W, Lee, HS, Kim, SD, Kim, SH, Kim, CY, Park, KH, Park, YJ, Baek, SH, Song, SJ, et al
Korean journal of ophthalmology : KJO. 2015;(6):359-67
Abstract
The Korea National Health and Nutrition Examination Survey (KNHANES) is a national program designed to assess the health and nutritional status of the noninstitutionalized population of South Korea. The KNHANES was initiated in 1998 and has been conducted annually since 2007. Starting in the latter half of 2008, ophthalmologic examinations were included in the survey in order to investigate the prevalence and risk factors of common eye diseases such as visual impairment, refractive errors, strabismus, blepharoptosis, cataract, pterygium, diabetic retinopathy, age-related macular degeneration, glaucoma, dry eye disease, and color vision deficiency. The measurements included in the ophthalmic questionnaire and examination methods were modified in the KNHANES IV, V, and VI. In this article, we provide detailed information about the methodology of the ophthalmic examinations in KNHANES in order to aid in further investigations related to major eye diseases in South Korea.
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7.
Osteoporosis in Korea.
Yoon, HK, Lee, BS, Park, KH, Park, JH, Jeong, KA
Clinical calcium. 2004;(9):123-7
Abstract
The increasing occurrence and high cost of osteoporosis pose an enormous public health problem. With continued aging of the populations, osteoporotic fractures may reach one of the major problem in Korea as well as in Asian countries. Although the prevalence of osteoporosis in Korea is somewhat not consistent because of different areas and machines measured bone mass, occurrence of hip fractures have increased about 4 folds during past 10 years. There is no satisfactory way to build up lost bone, thus, prevention is the best way which includes adequate intake of calcium, vitamin D, and protein, exercise, and stop smoking. As a second approach, pharmacologic therapy may be emphasized. Since most of pharmacologic agents for osteoporosis are available in Korea though their reimbursements are limited, preventive measures and pharmacologic therapies should be encouraged to attempt to reduce fragility fractures. Many doctors who work in the field of bone metabolism are establishing the new guidelines for osteoporosis and also attempt to revise the criteria for reimbursement nowadays. New paradigm for osteoporosis will be come and be utilized for clinical applications in the near future.
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8.
Structure, specificity and function of cyclomaltodextrinase, a multispecific enzyme of the alpha-amylase family.
Park, KH, Kim, TJ, Cheong, TK, Kim, JW, Oh, BH, Svensson, B
Biochimica et biophysica acta. 2000;(2):165-85
Abstract
Cyclomaltodextrinase (CDase, EC 3.2.1.54), maltogenic amylase (EC 3. 2.1.133), and neopullulanase (EC 3.2.1.135) are reported to be capable of hydrolyzing all or two of the following three types of substrates: cyclomaltodextrins (CDs); pullulan; and starch. These enzymes hydrolyze CDs and starch to maltose and pullulan to panose by cleavage of alpha-1,4 glycosidic bonds whereas alpha-amylases essentially lack activity on CDs and pullulan. They also catalyze transglycosylation of oligosaccharides to the C3-, C4- or C6-hydroxyl groups of various acceptor sugar molecules. The present review surveys the biochemical, enzymatic, and structural properties of three types of such enzymes as defined based on the substrate specificity toward the CDs: type I, cyclomaltodextrinase and maltogenic amylase that hydrolyze CDs much faster than pullulan and starch; type II, Thermoactinomyces vulgaris amylase II (TVA II) that hydrolyzes CDs much less efficiently than pullulan; and type III, neopullulanase that hydrolyzes pullulan efficiently, but remains to be reported to hydrolyze CDs. These three types of enzymes exhibit 40-60% amino acid sequence identity. They occur in the cytoplasm of bacteria and have molecular masses from 62 to 90 kDa which are slightly larger than those of most alpha-amylases. Multiple amino acid sequence alignment and crystal structures of maltogenic amylase and TVA II reveal the presence of an N-terminal extension of approximately 130 residues not found in alpha-amylases. This unique N-terminal domain as seen in the crystal structures apparently contributes to the active site structure leading to the distinct substrate specificity through a dimer formation. In aqueous solution, most of these enzymes show a monomer-dimer equilibrium. The present review discusses the multiple specificity in the light of the oligomerization and the molecular structures arriving at a clarified enzyme classification. Finally, a physiological role of the enzymes is proposed.