67 research outputs found
Relationship Between Earlobe Crease and Brachial-ankle Pulse Wave Velocity in Non-hypertensive, Non-diabetic Adults in Korea
OBJECTIVES: Several studies have found a significant association between the presence of earlobe crease (ELC) and cardiovascular disease (CVD). Brachial-ankle Pulse Wave Velocity (baPWV) is a non-invasive and useful measure of arterial stiffness predicting cardiovascular events and mortality. However, few studies have reported the relationship between ELC and baPWV as a new measure of arterial stiffness. the purpose of this study was to determine whether ELC is related to baPWV in non-diabetic, non-hypertensive, and apparently healthy Korean adults.
METHODS: A cross-sectional study was conducted on 573 non-hypertensive, non-diabetic Korean adults aged 20-80 yr. Subjects were stratified into three groups according to gender and menopausal status. baPWV was measured by an automatic waveform analyser. the association between ELC and baPWV was assessed by multiple linear regression analysis after adjusting for conventional cardiovascular disease risk factors including age, gender, blood pressure, lipid profile, and smoking status etc.
RESULTS: the overall frequency of ELC was 19.02% and the subjects with ELC showed significantly higher mean baPWV (p<0.0001). Multiple linear regression of subjects revealed that the presence of ELC was independently associated with baPWV (male, p<0.0001; premenopausal female p=0.0162; postmenopausal female p=0.0208).
CONCLUSION: ELC had a significant correlation with baPWV, independently controlling for other classical cardiovascular risk factors in adults aged 20 yr or older. ELC is an important surrogate marker of increased arterial stiffness as measured by baPWV in Korean adults.ope
Dependence of reaction center-type energy-dependent quenching on photosystem II antenna size
AbstractThe effects of photosystem II antenna size on reaction center-type energy-dependent quenching (qE) were examined in rice plants grown under two different light intensities using both wild type and qE-less (OsPsbS knockout) mutant plants. Reaction center-type qE was detected by measuring non-photochemical quenching at 50 μmol photons m−2 s−1 white light intensity. We observed that in low light-grown rice plants, reaction center-type qE was higher than in high light-grown plants, and the amount of reaction center-type qE did not depend on zeaxanthin accumulation. This was confirmed in Arabidopsis npq1–2 mutant plants that lack zeaxanthin due to a mutation in the violaxanthin de-epoxidase enzyme. Although the electron transport rate measured at a light intensity of 50 μmol photons m−2 s−1 was the same in high light- and low light-grown wild type and mutant plants lacking PsbS protein, the generation of energy-dependent quenching was completely impaired only in mutant plants. Analyses of the pigment content, Lhcb proteins and D1 protein of PSII showed that the antenna size was larger in low light-grown plants, and this correlated with the amount of reaction center-type qE. Our results mark the first time that the reaction center-type qE has been shown to depend on photosystem II antenna size and, although it depends on the existence of PsbS protein, the extent of reaction center-type qE does not correlate with the transcript levels of PsbS protein. The presence of reaction center-type energy-dependent quenching, in addition to antenna-type quenching, in higher plants for dissipation of excess light energy demonstrates the complexity and flexibility of the photosynthetic apparatus of higher plants to respond to different environmental conditions
Development of Laser Ruler in Rigid Laryngoscope
ObjectivesThe objective of this study was to develop a new device that provides a simple, noninvasive method of measuring accurate lesion size while using an endoscope.MethodsWe developed a rigid laryngoscope with a built-in laser-ruler using a one-light emitting diode and an acrylic plate. The invention incorporates a built-in laser diode that projects an auto-parallel beam into the optical path of the rigid laryngoscope to form two spots in the field of view.ResultsWhile the interspot distance remains consistent despite changes in focal plane, magnification, or viewing angle of the laryngoscope, projection to an uneven surface introduces certain variations in the shape, and size of the spots, and the distance between the two spots.ConclusionThe device enables a laryngologist to easily measure the distance between landmarks, as well as the change in real size, and the progressive change of vocal fold lesions in an outpatient setting
The Effect of Stimulation Frequency on the Ionic Currents in Single Atrial Cells of the Rabbit
In single atrial cells isolated from rabbit hearts the calcium current and
[Caj-dependent transient outward current were recorded using the whole-cell clamp
technique and the effect of stimulation frequency on these currents was investigated.
Voltage dependent transient outward current, which contributes the initial, rapid
repolarization phase of the action potential and is frequency-dependent, was also
investigated. Increasing the stimulation frequency from O. 025 Hz to 1 Hz had no effect
on the calcium current and [Caj-dependent transient outward current and greatly
inhibited voltage-dependent transient outward current. The amplitude of voltage dependent
transient outward current increased as the membrane potential became
depolarized, its steady-state inactivation spans the voltage range -70 mV to -10 mVand
steady-state activation curve -30 mV to 30 mV. Within the range of the resting membrane
potential (at -70 mV), the voltage-dependent recovery time constant was 1. 3 s.
The reversal potential was about -50 mV. Voltage-dependent transient outward current
was inhibited by K-channel blockers and not inhibited by modulation of [Cali. From the
above findings, it is concluded that due to the amplitude and voltage-dependent recovery
time constant which were the basic mechanisms for frequency-dependency, the
voltage- dependent transient outward current contributes the initial, rapid repolarization
phase and changed the action potential configuration according to stimulation frequency
in the rabbit atrium
Clinical Predictors of Novel Influenza A (H1N1) Infection in Korea
PURPOSE: Pandemic influenza A (H1N1) virus has spread rapidly and prompt diagnosis is needed for successful treatment and prevention of transmission. We investigated clinical predictors, validated the use of previous criteria with laboratory tests, and evaluated the clinical criteria for H1N1 infection in the Korean population.
MATERIALS AND METHODS: We analyzed clinical and laboratory evaluation data from outpatient clinics at Severance Hospital in Seoul, Korea between November 11 and December 5, 2009.
RESULTS: This analysis included a total of 828 patients. Of these, 372 (44.9%) patients were confirmed with H1N1 infection by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The most common and predictive symptom was cough (90.3%, OR 8.87, 95% CI 5.89- 13.38) and about 40% of H1N1-positive patients were afebrile. The best predictive model of H1N1 infection was cough plus fever or myalgia. The sensitivities, specificities, positive predictive values, and negative predictive values of our suggested criteria were 73.9%, 69.5%, 66.4%, and 76.6%, respectively.
CONCLUSION: Cough was the most common independent symptom in patients with laboratory-confirmed H1N1 infection, and while not perfect, the combination of cough plus fever or myalgia is suggested as clinical diagnostic criteria. Health care providers in Korea should suspect a cough without fever to be an early symptom of H1N1 infection.ope
Preparation of large Cu3Sn single crystal by Czochralski method
Cu3Sn was recently predicted to host topological Dirac fermions, but related research is still in its infancy. The growth of large and high-quality Cu3Sn single crystals is, therefore, highly desired to investigate the possible topological properties. In this work, we report the single crystal growth of Cu3Sn by Czochralski (CZ) method. Crystal structure, chemical composition, and transport properties of Cu3Sn single crystals were analyzed to verify the crystal quality. Notably, compared to the mm-sized crystals from a molten Sn flux, the cm-sized crystals obtained by the CZ method are free from contamination from flux materials, paving the way for the follow-up works
Role of TNFR-related 2 mediated immune responses in dextran sulfate sodium-induced inflammatory bowel disease
Previous work has suggested that the LIGHT-TR2 costimulatory pathway plays a role in the acute and chronic stages of dextran sulfate sodium (DSS)-induced colitis [Steinberg et al. (2008); Wang et al. (2005)]. To clarify the role of TNFR-related 2 (TR2) signaling in the maintenance of intestinal homeostasis, we generated a TR2 knock-out (KO) mouse. Using DSS to induce colitis, we compared the colitic symptoms and pathological changes in wild type (WT) and TR2 KO mice, and the production of cytokines by the diseased colons. We also studied the role of TR2 in suppressing innate and adaptive immunity in the DSS model. TR2 deficient mice were characterized by reduced symptoms of intestinal inflammation compared with wildtype mice, and reduced production of cytokines. We therefore generated a monoclonal antibody against mouse TR2 which was specific to TR2 and capable of blocking TR2 signals. With this antibody, we demonstrated that antagonizing TR2 during the development of DSS-induced colitis reduced the symptoms of inflammation. Our findings suggest that TR2 is an important mediator in colitis, and may serve as a therapeutic target in inflammatory bowel disease
High-dose clevudine impairs mitochondrial function and glucose-stimulated insulin secretion in INS-1E cells
<p>Abstract</p> <p>Background</p> <p>Clevudine is a nucleoside analog reverse transcriptase inhibitor that exhibits potent antiviral activity against hepatitis B virus (HBV) without serious side effects. However, mitochondrial myopathy has been observed in patients with chronic HBV infection taking clevudine. Moreover, the development of diabetes was recently reported in patients receiving long-term treatment with clevudine. In this study, we investigated the effects of clevudine on mitochondrial function and insulin release in a rat clonal β-cell line, INS-1E.</p> <p>Methods</p> <p>The mitochondrial DNA (mtDNA) copy number and the mRNA levels were measured by using quantitative PCR. MTT analysis, ATP/lactate measurements, and insulin assay were performed.</p> <p>Results</p> <p>Both INS-1E cells and HepG2 cells, which originated from human hepatoma, showed dose-dependent decreases in mtDNA copy number and cytochrome c oxidase-1 (Cox-1) mRNA level following culture with clevudine (10 μM-1 mM) for 4 weeks. INS-1E cells treated with clevudine had reduced total mitochondrial activities, lower cytosolic ATP contents, enhanced lactate production, and more lipid accumulation. Insulin release in response to glucose application was markedly decreased in clevudine-treated INS-1E cells, which might be a consequence of mitochondrial dysfunction.</p> <p>Conclusions</p> <p>Our data suggest that high-dose treatment with clevudine induces mitochondrial defects associated with mtDNA depletion and impairs glucose-stimulated insulin secretion in insulin-releasing cells. These findings partly explain the development of diabetes in patients receiving clevudine who might have a high susceptibility to mitochondrial toxicity.</p
Effects of Gelidium elegans on Weight and Fat Mass Reduction and Obesity Biomarkers in Overweight or Obese Adults: A Randomized Double-Blinded Study
The edible seaweed Gelidium elegans (GEE) is known to inhibit adipocyte differentiation. However, there has been no report on its effects in humans. In this study, we investigated whether GEE reduces body weight or fat mass in obese or overweight individuals. A total of 78 participants were randomly assigned to the test (GEE extract 1000 mg/day) and placebo groups at a 1:1 ratio, and treated for 12 weeks. At six or 12 weeks after randomization, they were evaluated for anthropometric parameters, biomarkers, and body composition. Changes in body weight and fat mass between the two groups was significantly different, as determined using ANCOVA adjusted for baseline, calorie intake, and physical activity. Body weight and fat mass were significantly decreased by GEE after 12 weeks but increased in the placebo group. Moreover, although not significant, triglyceride levels tended to decrease after GEE intake. There was no significant difference in other laboratory biomarkers between the two groups. Taken together, these results suggested that GEE significantly reduced body weight, especially fat mass, in overweight or obese individuals
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