BACKGROUND: Hyperhomocysteinemia as a risk factor for cerebrovascular disease is well known. Our aim of this study was to demonstrate positive association between elevated homocysteine levels and cerebrovascular diseases in Koreans. METHODS: With a case-control design, 186 stroke (infarction 134, hemorrhage 52) patients, diagnosed by brain CT or MRI and 359 control patients were evaluated. We used multiple logistic regression analyses conditioned on the matching variables (sex, age, hypertension, DM, smoking, hyperlipidemia, hyperhomocysteinemia) and calculated odds ratio and 95% CIs. RESULTS: Multivariated adjusted odds ratios (OR) for cerebrovascular diseases associated with hypertension compared with normal blood pressure were 2.45 (95% CI, 1.16 to 5.15) in prehypertension and 3.33 (95% CI, 1.56 to 7.10) in stage 1 hypertension and 3.77 (95% CI, 1.32 to 10.74) in stage 2 hypertension. OR for cerebrovascular diseases associated with hyperhomocysteinemia compared with <10micromol/L were 2.06 (95% CI, 1.09 to 3.91) in 13.0 to 16.9micromol/L and 3.17 (95% CI, 1.70 to 5.90) in > or =17 micromol/L. CONCLUSION: Not only hypertension but also hyperhomocysteinemia was a significant risk factor for cerebrovascular diseases in Koreans.
Asian Continental Ancestry Group ; Blood Pressure ; Brain ; Case-Control Studies ; Hemorrhage ; Homocysteine ; Humans ; Hyperhomocysteinemia* ; Hyperlipidemias ; Hypertension ; Logistic Models ; Magnetic Resonance Imaging ; Odds Ratio ; Prehypertension ; Risk Factors ; Smoke ; Smoking ; Stroke

PURPOSE: B1 field of birdcage RF (radiofrequency) coil that is used most for brain imaging in magnetic resonance imaging (MRI) decreases toward endring from the coil center. We investigated how much RF B1 homogeneity effect the endcap shield brings form the coil center as it towards to endcap region. MATERIALS AND METHODS: We compared RF B1 field distribution by each finite difference time domain (FDTD) simulations for lowpass, highpass and hybrid birdcage RF coils. We selected the highpass birdcage RF coil that was the highest RF B1 field condition as simulation result, and studied how much RF B1 homogeneity effect was occurred when endcap shield was applied to endring area. RESULTS: B1 field of the highpass birdcage RF coil was higher than other birdcage RF coil types as simulation result. However, the RF B1 homogeneity was lower than other coil types. RF B1 field of highpass birdcage RF coil with endcap shield is similar with RF B1 field of hybrid birdcage RF coil and the overall RF B1 homogeneity in sagittal direction was better. CONCLUSION: In this paper, proposed method can apply improving RF B1 homogeneity of RF coil in clinical examination.
Magnetic Resonance Imaging* ; Neuroimaging

BACKGROUND: We evaluated the associations between 25-hydroxyvitamin D (25(OH)D) concentrations in serum and insulin resistance in the healthy Korean population. METHODS: We conducted this cross-sectional analysis in 1,807 healthy Korean people (628 men and 1,179 women) aged 30 to 64 years in the Cardiovascular and Metabolic Disease Etiologic Research Center study. All participants were assessed for 25(OH)D, fasting glucose, and insulin levels, and completed a health examination and lifestyle questionnaire according to standard procedures. Insulin resistance was defined as the homeostasis model assessment insulin resistance higher than the 75 percentile. RESULTS: Compared to those in the highest tertile (≥14.3 ng/mL), the odds ratio (OR) for insulin resistance was 1.37 (95% confidence interval [CI], 1.01 to 1.86) for the 1st tertile (<9.7 ng/mL) and 1.19 (95% CI, 0.08 to 1.62) for the 2nd tertile (9.7 to 14.3 ng/mL) after adjusting for age, gender, waist circumference, alcohol consumption, smoking status, physical exercise, season, and cohort. After stratification of the subjects by adiposity, these associations remained only in non-obese subjects (lowest tertile vs. highest tertile, multivariable OR, 1.64; 95% CI, 1.05 to 2.56). CONCLUSION: Serum 25(OH)D has an independent inverse association with insulin resistance in the healthy, non-obese Korean population, even among people with vitamin D insufficiency.
Adiposity ; Alcohol Drinking ; Cohort Studies ; Cross-Sectional Studies ; Exercise ; Fasting ; Glucose ; Homeostasis ; Humans ; Insulin Resistance* ; Insulin* ; Life Style ; Male ; Metabolic Diseases ; Obesity ; Odds Ratio ; Seasons ; Smoke ; Smoking ; Vitamin D ; Waist Circumference

BACKGROUND: Activation of G-protein coupled-somatostatin receptors induces the release of calcium from inositol 1, 4, 5-trisphosphate-sensitive intracelluar stores. G-protein-coupled receptor signaling decreases with prolonged exposure to an agonist. SEBJECTS and METHODS: Fura-2-based digital Ca2+ imaging was used to study the effects of prolonged exposure to an agonist on the somatostatin-induced intracellular Ca2+ concentration([Ca2+]i) increases in NG108-15 cells, which were differentiated with CO2-independent medium and 10micrometer forskolin. RESULTS: Exposure to somatostatin(1micrometer) for 30 min completely desensitized the NG108-15 cells to a second somatostatin-induced response. The cells recovered gradually over 20 min following washout of the somatostatin. The desensitization was not due to depletion of the intracellular Ca2+ stores, and pretreatment for 30 min with bradykinin(100nM), which activates phospholipase C, or DADLE(D-Ala2-D-Leu5 enkephalin, 1microM), which activates phospholipase C, failed to cross-desensitize the somatostatin-evoked [Ca2+]i increases. Treatment with 8-cpt-cAMP(0.1mM) for 30min did not influence the somatostatin-induced[Ca2+]i increases. Phorbol 12, 13-dibutyrate(PdBu, 1microM) blocked the response completely. Down-regulation of PKC due to 24 h exposure of PdBu (1microM) inhibited the somatostatin-induced desensitization. CONCLUSION: Prolonged exposure of somatostatin to NG108-15 cells desensitized the somatostatin-induced release of Ca2+ from the intracelluar store, with protein kinase C also involved in the desensitization.
Calcium* ; Colforsin ; Down-Regulation ; Enkephalins ; GTP-Binding Proteins ; Inositol ; Protein Kinase C* ; Protein Kinases* ; Somatostatin ; Type C Phospholipases

OBJECTIVES: With the rapid increase in the prevalence of diabetes, the age groups of diabetic patients are becoming diversified. This study will examine the degree of obesity, insulin resistance, and insulin secretion ability among patients first diagnosed with diabetes according to age and gender. METHODS: The subjects of this study included 616 patients who were first diagnosed with diabetes during a routine physical examination. This sample was obtained from a total of 28,075 adults aged 19 years and older who received the examination among 33,829 participants in the Korea National Health & Nutrition Examination Survey (KNHANES) from 2007–2010. The subjects were categorized by age into young age (age: 19 – 39 years), middle age (age: 40 – 59 years), and old age (age: 60 years and older). The degree of obesity was categorized according to body mass index (BMI) into normal weight (BMI: 18.5 ~ 22.9), overweight (BMI: 23 ~ 24.9), and obesity (BMI: 25 or above). Insulin resistance was evaluated by homeostatic model assessment of insulin resistance (HOMA-IR). RESULTS: It was found that 14.1% (n = 87) of a total of 616 subjects (324 men, 292 women) were in the young age group, 43.8% (n = 270) were in the middle age group, and 42.1% (n = 259) were in the old age group. In addition, 83.3% of men that were overweight or obesity were in the young age group, while 79.2% and 60.5% were in the middle age and old age groups, respectively. A total of 82.2% of women that were overweight or obesity were in the young age group, while 79.5% and 77% were in the middle age and old age groups, respectively. For men, the more obesity they were in all age groups, the higher their HOMA-IR. For women, the more obesity they were in the young age and middle age groups, the higher their HOMA-IR; however, women in the old age group showed the highest HOMA-IR when they were of normal weight. CONCLUSION: Among diabetic patients first diagnosed with the disease in Korea, the youth population had the highest obesity rate. Insulin resistance increases as an individual's weight increases among those patients who are first diagnosed with diabetes; the only exception noted is for elderly women.
Adolescent ; Adult ; Aged ; Bodily Secretions ; Body Mass Index ; Female ; Humans ; Insulin Resistance* ; Insulin* ; Korea* ; Male ; Middle Aged ; Obesity* ; Overweight ; Physical Examination ; Prevalence