• Title/Summary/Keyword: Biophysics

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Polymorphisms of SLC22A9 (hOAT7) in Korean Females with Osteoporosis

  • Ahn, Seong Kyu;Suh, Chang Kook;Cha, Seok Ho
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.4
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    • pp.319-325
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    • 2015
  • Among solute carrier proteins, the organic anion transporters (OATs) play an important role for the elimination or reabsorption of endogenous and exogenous negatively charged anionic compounds. Among OATs, SLC22A9 (hOAT7) transports estrone sulfate with high affinity. The net decrease of estrogen, especially in post-menopausal women induces rapid bone loss. The present study was performed to search the SNP within exon regions of SLC22A9 in Korean females with osteoporosis. Fifty healthy controls and 50 osteoporosis patients were screened for the genetic polymorphism in the coding region of SLC22A9 using GC-clamped PCR and denaturing gradient gel electrophoresis (DGGE). Six SNPs were found on the SLC22A9 gene from Korean women with/without osteoporosis. The SNPs were located as follows: two SNPs in the osteoporosis group (A645G and T1277C), three SNPs in the control group (G1449T, C1467T and C1487T) and one SNP in both the osteoporosis and control groups (G767A). The G767A, T1277C and C1487T SNPs result in an amino acid substitution, from synonymous vs nonsynonymous substitution arginine to glutamine (R256Q), phenylalanine to serine (F426S) and proline to leucine (P496L), respectively. The Km values and Vmax of the wild type, R256Q, P496L and F426S were 8.84, 8.87, 9.83 and $12.74{\mu}M$, and 1.97, 1.96, 2.06 and 1.55 pmol/oocyte/h, respectively. The present study demonstrates that the SLC22A9 variant F426S is causing inter-individual variation that is leading to the differences in transport of the steroid sulfate conjugate (estrone sulfate) and, therefore this could be used as a marker for certain disease including osteoporosis.

Development of Estimation Methods of Skin Oxidation and Evaluation of Anti-Oxidative Effects of Genistein in Topical Formulations

  • Kim, Seong-Yeon;Na, Yeon-Joo;Kim, Dong-Ju;Kim, Yeong-Seok;Kim, Hyeong-Min;Hwang, Sung-Ha;Kwak, Ji-Yeon;Kuh, Hyo-Jeong;Lee, Jae-Hwi
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.3
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    • pp.205-209
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    • 2012
  • The objective of the present study was to establish the method of measurement of hydrogen peroxide and to estimate the anti-oxidative effect of genistein in the skin. UVB induced skin oxidation and anti-oxidative effect of genistein formulations were evaluated by determining levels of hydrogen peroxide. The mechanism involved in the determination of hydrogen peroxide is based on a color reaction between ferric ion ($Fe^{3+}$) and xylenol orange, often called FOX assay and subsequent monitoring of absorbance values of the reactant at 540 nm. The reaction was to some extent pH-dependent and detection sensitivity was greatest at pH 1.75. Genistein liposomal gel demonstrated better anti-oxidative effect with regard to lowering hydrogen peroxide levels elevated by UVB irradiation compared to genistein-suspended gel. A linear relationship has been observed between anti-oxidative effect of genistein and drug deposition in the skin tissue. Genistein liposomal gel resulting in the localization of the drug in the deeper skin led to improved anti-oxidative effect compared to genistein gel. The suggested method for evaluation of oxidation of the skin can be used as a tool to screen effective anti-oxidative agents and their delivery systems acting on the skin.

Push-out bond strength and dentinal tubule penetration of different root canal sealers used with coated core materials

  • Sungur, Derya Deniz;Purali, Nuhan;Cosgun, Erdal;Calt, Semra
    • Restorative Dentistry and Endodontics
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    • v.41 no.2
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    • pp.114-120
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    • 2016
  • Objectives: The aim of this study was to compare the push-out bond strength and dentinal tubule penetration of root canal sealers used with coated core materials and conventional gutta-percha. Materials and Methods: A total of 72 single-rooted human mandibular incisors were instrumented with NiTi rotary files with irrigation of 2.5% NaOCl. The smear layer was removed with 17% ethylenediaminetetraacetic acid (EDTA). Specimens were assigned into four groups according to the obturation system: Group 1, EndoRez (Ultradent Product Inc.); Group 2, Activ GP (Brasseler); Group 3, SmartSeal (DFRP Ltd. Villa Farm); Group 4, AH 26 (Dentsply de Trey)/gutta-percha (GP). For push-out bond strength measurement, two horizontal slices were obtained from each specimen (n = 20). To compare dentinal tubule penetration, remaining 32 roots assigned to 4 groups as above were obturated with 0.1% Rhodamine B labeled sealers. One horizontal slice was obtained from the middle third of each specimen (n = 8) and scanned under confocal laser scanning electron microscope. Tubule penetration area, depth, and percentage were measured. Kruskall-Wallis test was used for statistical analysis. Results: EndoRez showed significantly lower push-out bond strength than the others (p < 0.05). No significant difference was found amongst the groups in terms of percentage of sealer penetration. SmartSeal showed the least penetration than the others (p < 0.05). Conclusions: The bond strength and sealer penetration of resin-and glass ionomer-based sealers used with coated core was not superior to resin-based sealer used with conventional GP. Dentinal tubule penetration has limited effect on bond strength. The use of conventional GP with sealer seems to be sufficient in terms of push-out bond strength.

Affinity Immobilization of Dextransucrase on Dextran-based Support and the Production of Leucrose

  • Han, Nam-Soo;Kang, Seung-Yeon;Lee, Soo-Bok;Robyt, John F.
    • Food Science and Biotechnology
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    • v.14 no.3
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    • pp.317-322
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    • 2005
  • A simple and convenient method of immobilizing dextransucrase via an affinity interaction is described, along with the use of this system to synthesize leucrose. Dextransucrase was produced in sucrose-free medium by fermenting a constitutive mutant of Leuconostoc mesenteroides NRRL B-512F and was separated using an ultrafiltration membrane. The purified enzyme was free of dextran polymer, which previously was always found with the sucrose-induced enzyme. Therefore, it was possible to immobilize the enzyme on dextran-based resins using an affinity interaction. Sephadex G-200 was the best resin for immobilizing the dextransucrase and gave a fast flow rate through the packed column. The immobilized dextransucrase retained more than 80% of its specific activity after immobilization ($K_m\;=\;18.1\;mM$ and $k_{cat}\;=\;450\;sec^{-1}$ vs. 13.1 mM and $640\;sec^{-1}$, respectively, for the free enzyme). The immobilized dextransucrase showed improved stability over a pH range of 4.0 to 6.5 and at moderately high temperatures over $40^{\circ}C$. When immobilized dextransucrase was used to synthesize leucrose via the transfer reaction with sucrose and fructose, about 74% of the sucrose was converted into leucrose after one day, and the half-life of the enzyme activity was 15 days. Regeneration of the resin by supplementation with dextransucrase enabled the recovery of the initial activity of the system, but both the reaction and the flow rate were lower, probably owing to the accumulation of dextran inside the resin.

Evaluation of Functional Ability and Nutritional Risk according to Self-Rated Health (SRH) of the Elderly in Seoul and Kyunggi-do (서울 및 경기지역 노인의 건강자가평가에 따른 기능적 건강 및 영양위험 평가)

  • Choi, Yoon-Jung;Park, Yu-Sin;Kim, Chan;Jang, Yu-Kyung
    • Journal of Nutrition and Health
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    • v.37 no.3
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    • pp.223-235
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    • 2004
  • A functional ability and adequate nutritional status are the major determinants of health status, Self-rated health (SRH) is a worldwide method to assess health status and it is recognized as a predictor of morbidity and mortality in the elderly, This study was designed to evaluate the functional ability and nutritional risk according to SRH in the elderly. Four hundred nine free-living elderly people (118 male, 291 female), aged $\geq$ 65 years were interviewed by trained interviewers using structured questionnaires including demographic information, SRH, anthropometric measurements, functional ability, general health status, and nutritional risk. SRH was divided into three status such as “Good”, “Moderate” and “Poor” status. And all the data were analyzed by oneway ANOVA, spearman correlation, and x$^2$ analysis using SPSS 9.0 version at p 〈 0.05. Of all the subjects, 48.9% perceived their health status as “poor”, and their functional abilities (activities of daily living, instrumental activities of daily living) were more impaired than their counterparts (“good” and “moderate”). Poor self-rated health was also related to: a higher prevalence of illnesses (p 〈 0,001) especially in hypertension, arthritis. Self-rated health was significantly related to food security (p 〈 0.001), food enjoyment (p 〈 0.001) ,and nutritional knowledge (p = 0.0 13). Also NSI checklist total score was the highest in “poor” health status (p 〈 0.001). Better self-rated health was related to better food security, and better food enjoyment. However, smoking, alcoholic intake, exercise, eating behaviors, and demographic characteristics were not significantly different among the three SRH status. SRH was closely related to chronic diseases, functional ability, and nutritional risk in the elderly. Therefore, public health strategies for the elderly should be focused on the elderly who are “poor” in SRH, to improve nutritional status and functional ability, and to reduce risk factors of chronic diseases.

Bending and buckling analyses of functionally graded material (FGM) size-dependent nanoscale beams including the thickness stretching effect

  • Chaht, Fouzia Larbi;Kaci, Abdelhakim;Houari, Mohammed Sid Ahmed;Tounsi, Abdelouahed;Beg, O. Anwar;Mahmoud, S.R.
    • Steel and Composite Structures
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    • v.18 no.2
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    • pp.425-442
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    • 2015
  • This paper addresses theoretically the bending and buckling behaviors of size-dependent nanobeams made of functionally graded materials (FGMs) including the thickness stretching effect. The size-dependent FGM nanobeam is investigated on the basis of the nonlocal continuum model. The nonlocal elastic behavior is described by the differential constitutive model of Eringen, which enables the present model to become effective in the analysis and design of nanostructures. The present model incorporates the length scale parameter (nonlocal parameter) which can capture the small scale effect, and furthermore accounts for both shear deformation and thickness stretching effects by virtue of a sinusoidal variation of all displacements through the thickness without using shear correction factor. The material properties of FGM nanobeams are assumed to vary through the thickness according to a power law. The governing equations and the related boundary conditions are derived using the principal of minimum total potential energy. A Navier-type solution is developed for simply-supported boundary conditions, and exact expressions are proposed for the deflections and the buckling load. The effects of nonlocal parameter, aspect ratio and various material compositions on the static and stability responses of the FGM nanobeam are discussed in detail. The study is relevant to nanotechnology deployment in for example aircraft structures.

The Action of Triterpenoidal Glycosides of Dammarane Series and Their Aglycones on $K^{+}$ and $H^{-}$ Fluxes in Erythrocytes, Induced by lonophore $A_{23187}$ and Divalent ions ($A_{23187}$과 2가 이온에 의해 일어나는 $K^{+}$ 이온과 $H^{-}$ 이온의 흐름에 미치는 Triterpenoidal Dammarane Serids의 Glycosides와 그 Aglycones의 영향)

  • Kim, Yu.A.;Park, Kyeong-Mee;Kyung, Jong-Su;Hyun, Hak-Chul;Song, Yong-Bum;Shin, Han-Jae;Park, Hwa-Jin
    • Journal of Ginseng Research
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    • v.20 no.2
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    • pp.168-172
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    • 1996
  • Ginsenoside Rb,, at a concentration of 10 $\mu\textrm{g}$/ml and over, initiated the cycle of oscillation of ion flux in erythrocytes after the cells had been treated with a protonophore, carbonyl cyanide p-trifluoro-methoxyphenyl hydrazone (FCCP) and then with a $Ca^{2+}$ ionophore, A23,3,. Its action was similar to the additional portion of $Ca^{2+}$-ionophore or $Ca^{2+}$ ion to the erythrocytes. Effects of $Rg_1$ and Rf were different from that of Rb,. They did not induce the oscillation. They, however, increased the extracellular $K^{+}$ concentration and pH without returning to the initial state in the erythrocytes processed with FCCP and $A_{23187}$. We established that ginsenosides from 20-(5)-panaxatriol family induced the membrane hyperpolarization in erythrocytes, which was attenuated by the pretreatment of $Rb_1$, a major component of 20-(5)-panaxadiol.

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Kinetics, Isotherm and Adsorption Mechanism Studies of Letrozole Loaded Modified and Biosynthesized Silver Nanoparticles as a Drug Delivery System: Comparison of Nonlinear and Linear Analysis

  • PourShaban, Mahsa;Moniri, Elham;Safaeijavan, Raheleh;Panahi, Homayon Ahmad
    • Korean Chemical Engineering Research
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    • v.59 no.4
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    • pp.493-502
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    • 2021
  • We prepared and investigated a biosynthesized nanoparticulate system with high adsorption and release capacity of letrozole. Silver nanoparticles (AgNPs) were biosynthesized using olive leaf extract. Cysteine was capped AgNPs to increase the adsorption capacity and suitable interaction between nanoparticles and drug. Morphology and size of nanoparticles were confirmed using transmission electron microscopy (TEM). Nanoparticles were spherical with an average diameter of less than 100 nm. Cysteine capping was successfully confirmed by Fourier transform infrared resonance (FTIR) spectroscopy and elemental analysis (CHN). Also, the factors of letrozole adsorption were optimized and the linear and non-linear forms of isotherms and kinetics were studied. Confirmation of the adsorption data of letrozole by cysteine capped nanoparticles in the Langmuir isotherm model indicated the homogeneous binding site of modified nanoparticles surface. Furthermore, the adsorption rate was kinetically adjusted to the pseudo-second-order model, and a high adsorption rate was observed, indicating that cysteine coated nanoparticles are a promising adsorbent for letrozole delivery. Finally, the kinetic release profile of letrozole loaded modified nanoparticles in simulated gastric and intestinal buffers was studied. Nearly 40% of letrozole was released in simulated gastric fluid with pH 1.2, in 30 min and the rest of it (60%) was released in simulated intestinal fluid with pH 7.4 in 10 h. These results indicate the efficiency of the cysteine capped AgNPs for adsorption and release of drug letrozole for breast cancer therapy.

The Changing Epidemiology of Gastroesophageal Reflux Disease: Are Patients Getting Younger?

  • Yamasaki, Takahisa;Hemond, Colin;Eisa, Mohamed;Ganocy, Stephen;Fass, Ronnie
    • Journal of Neurogastroenterology and Motility
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    • v.24 no.4
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    • pp.559-569
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    • 2018
  • Background/Aims Gastroesophageal reflux disease (GERD) is a common disease globally with increasing prevalence and consequently greater burden on the Healthcare system. Traditionally, GERD has been considered a disease of middle-aged and older people. Since risk factors for GERD affect a growing number of the adult population, concerns have been raised that increasingly younger people may develop GERD. We aim to determine if the proportion of younger patients has increased among the GERD population. Methods The incidence of GERD as well as several variables were evaluated during an 11-year period. Explorys was used to evaluate datasets at a "Universal" and Healthcare system in northern Ohio to determine if trends at a local level reflected those at a universal level. GERD patients were classified into 7 age groups (15-19, 20-29, 30-39, 40-49, 50-59, 60-69, and ${\geq}70$ years). Results The proportion of patients with GERD increased in all age groups, except for those who were ${\geq}70$ years in the universal dataset (P < 0.001) and those who were ${\geq}60$ years in the Healthcare system (P < 0.001). The greatest rise was seen in 30-39 years in both datasets (P < 0.001). Similarly, the proportion of GERD patients who were using proton pump inhibitors increased in all age groups except for those who were ${\geq}70$ years in both datasets (P < 0.001), with the greatest increase being the group 30-39 years (P < 0.001). Conclusion Over the last decade, there has been a significant increase in the proportion of younger patients with GERD, especially those within the age range of 30-39 years.

Impact of HIV-1 subtype and Korean Red Ginseng on AIDS progression: comparison of subtype B and subtype D

  • Cho, Young-Keol;Kim, Jung-Eun;Lee, Sun-Hee;Foley, Brian T.;Choi, Byeong-Sun
    • Journal of Ginseng Research
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    • v.43 no.2
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    • pp.312-318
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    • 2019
  • Background: To date, no study has described disease progression in Asian patients infected with HIV-1 subtype D. Methods: To determine whether the disease progression differs in patients infected with subtypes D and B prior to starting combination antiretroviral therapy, the annual decline (AD) in $CD^{4+}$ T cell counts over $96{\pm}59months$ was retrospectively analyzed in 163 patients and compared in subtypes D and B based on the nef gene. Results: $CD^{4+}$ T cell AD was significantly higher in the six subtype D-infected patients than in the 157 subtype B-infected patients irrespective of Korean Red Ginseng (KRG) treatment (p < 0.001). Of these, two subtype D-infected patients and 116 subtype B-infected patients had taken KRG. AD was significantly lower in patient in the KRG-treated group than in those in the $KRG-na{\ddot{i}}ve$ group irrespective of subtype (p < 0.05). To control for the effect of KRG, patients not treated with KRG were analyzed, with AD found to be significantly greater in subtype D-infected patients than in subtype B-infected patients (p < 0.01). KRG treatment had a greater effect on AD in subtype D-infected patients than in subtype B-infected patients (4.5-fold vs. 1.6-fold). Mortality rates were significantly higher in both the 45 $KRG-na{\ddot{i}}ve$ (p < 0.001) and all 163 (p < 0.01) patients infected with subtype D than subtype B. Conclusion: Subtype D infection is associated with a >2-fold higher risk of death and a 2.9-fold greater rate of progression than subtype B, regardless of KRG treatment.