Evaluation of Eye Irritation Potential of Solid Substance with New 3D Reconstructed Human Cornea Model, MCTT HCE(TM)

The eye irritation potential of drug candidates or pharmaceutical ingredients should be evaluated if there is a possibility of ocular exposure. Traditionally, the ocular irritation has been evaluated by the rabbit Draize test. However, rabbit eyes are more sensitive to irritants than human eyes, therefore substantial level of false positives are unavoidable. To resolve this species difference, several three-dimensional human corneal epithelial (HCE) models have been developed as alternative eye irritation test methods. Recently, we introduced a new HCE model, MCTT HCETM which is reconstructed with non-transformed human corneal cells from limbal tissues. Here, we examined if MCTT HCETM can be employed to evaluate eye irritation potential of solid substances. Through optimization of washing method and exposure time, treatment time was established as 10 min and washing procedure was set up as 4 times of washing with 10 mL of PBS and shaking in 30 mL of PBS in a beaker. With the established eye irritation test protocol, 11 solid substances (5 non-irritants, 6 irritants) were evaluated which demonstrated an excellent predictive capacity (100% accuracy, 100% specificity and 100% sensitivity). We also compared the performance of our test method with rabbit Draize test results and in vitro cytotoxicity test with 2D human corneal epithelial cell lines.

Herbal extract THI improves metabolic abnormality in mice fed a high-fat diet

Target herbal ingredient (THI) is an extract made from two herbs, Scutellariae Radix and Platycodi Radix. It has been developed as a treatment for metabolic diseases such as hyperlipidemia, atherosclerosis, and hypertension. One component of these two herbs has been reported to have anti-inflammatory, anti-hyperlipidemic, and anti-obesity activities. However, there have been no reports about the effects of the mixed extract of these two herbs on metabolic diseases. In this study, we investigated the metabolic effects of THI using a diet-induced obesity (DIO) mouse model. High-fat diet (HFD) mice were orally administered daily with 250 mg/kg of THI. After 10 weeks of treatment, the THI-administered HFD mice showed reduction of body weights and epididymal white adipose tissue weights as well as improved glucose tolerance. In addition, the level of total cholesterol in the serum was markedly reduced. To elucidate the molecular mechanism of the metabolic effects of THI in vitro, 3T3-L1 cells were treated with THI, after which the mRNA levels of adipogenic transcription factors, including C/EBPalpha and PPARgamma, were measured. The results show that the expression of these two transcription factors was down regulated by THI in a dose-dependent manner. We also examined the combinatorial effects of THI and swimming exercise on metabolic status. THI administration simultaneously accompanied by swimming exercise had a synergistic effect on serum cholesterol levels. These findings suggest that THI could be developed as a supplement for improving metabolic status.

Contribution of Dietary Intakes of Antioxidants to Homocysteine-Induced Low Density Lipoprotein (LDL) Oxidation in Atherosclerotic Patients

PURPOSE: Elevated circulating oxidized low density lipoprotein (Ox-LDL) levels are associated with increased risk of atherosclerosis, which may be due to high plasma homocysteine (Hcy) and low intakes of antioxidants. We investigated the contribution of dietary intakes of antioxidants to Hcy-induced LDL oxidation in atherosclerotic patients (AP) and controls. MATERIALS AND METHODS: Male AP (n = 101) who were confirmed by coronary angiography and 91 controls were evaluated by blood biochemistry and dietary intakes. To determine whether homocysteine is an independent risk factor for atherosclerosis, subjects were divided into three groups; low- ( or = 12.1 uM/L) Hcy. RESULTS: Plasm levels of homocysteine and LDL were higher, but plasma apo A-I in HDL and folate were lower in the AP group. The odds ratio (OR) for the risk of atherosclerosis was 3.002 [95% confidence interval (CI), 1.27-7.09] for patients in the highest tertile with homocysteine > or = 12.1 uM/L. AP having high homocysteine levels had low intakes of vitamin A, beta-carotene and vitamin C. By logistic regression analysis, age, body mass index (BMI), plasma LDL, plasma folate, and low intakes of vitamin A and beta-carotene were found to be risk factors for atherosclerosis in patients with high-Hcy, but dietary B vitamins including folate were not. CONCLUSION: A high-Hcy level was a risk factor for atherosclerosis in patients with high Ox-LDL levels. High intakes of antioxidants appeared to be a protective factor for atherosclerosis, perhaps exerting a pro-oxidative effect on LDL when combined with high levels of Hcy and LDL. However, more evidence for the benefits of B vitamins as a homocysteine-lowering therapy is needed.

Apo E4 Genotype as the Alzheimer Indictor in Korean Senior Subjects Aged 50 to 64 Years Old

Recent studies described the epsilon 4 allele of apoE confers a two-to fourfold increased risk for late-onset Alzheimer's disease (LOAD), but LOAD pathology does not all fit neatly around apo E. Therefore, the goal of this study was to find the association between Alzheimer and apo E4 genotype in the 107 elderly between 50 to 64 years old who visited to FHWC of Sungshin Women's University. We conducted the questionnaire survey (general & 24 hr dietary recall), anthropometerics (BP, waist & BMI) and blood biochemistry (FBS & lipid profiles). LDL-c and HOMA-IR were calculated by Friedwald's and Matthew's formulas. The apo E genotyping was performed by PCR-RFLP method and subjects were divided into three allele groups (epsilon 3; wild, epsilon 2 & epsilon 4; mutants). The apo E allele frequencies were 7.0% for the epsilon 2, 83.6% for the epsilon 3 and 9.3% for the epsilon 4. In comparison with biochemistry characteristics by apo E genotype, FBS was significantly higher in epsilon 4 (129.2 +/- 6.8) than that in the others (epsilon 2: 117 +/- 7.4, epsilon 3: 107.3 +/- 2.2)(p 150 mg/dl) & low HDL (< 40 mg/dl: male symbol or < 50 mg/dl: female symbol )]. The cytokines levels such as IL-1beta, IL-6 and TNF-alpha were not different among three apoE alleles. After the adjusting sex, age & dietary fiber, LDL-c level was significantly higher in epsilon 4 (108.3 +/- 7.7) than that in epsilon 2 (100.4 +/- 8.4)(p < 0.05). According to food intake and the recipe on the basis of 24 hr dietary recall, the elderly with epsilon 4 allele took higher intake frequency of the light -colored vegetable (radish, onion & cabbage) and pan-fried foods (sauteed beef and vegetables, stir-fried vienna with vegetables) than the others. We knew that the elderly with epsilon 4 allele had been restricted the calories intakes with high dietary fiber (33.6 + 2.5 g/d) to maintain the normal level of FBS and LDL-c. On next study, the prevalence of Alzheimer's disease in this population who has epsilon 4 allele on the condition of calories restriction will be continually follow-up.

Clinical Usefulness of Transesophageal Echocardiography in Detecting Infections of Implanted Intracardiac Electrodes:3 Cases of Electrodes Related Infective Endocarditis

Vegetative electrode infection after implantation of permanent pacemaker or defibrillator is an uncommon but a serious complication. Diagnosis of the lead infection is particularly important since surgical manipulation is usually required for its treatment. We present 3 cases of electrodes related infective endocarditis among the 154 patients who implanted pacemaker or defibrillator between 2001 and 2004 in Korea university hospital. These complications were difficult to diagnose because of ambiguous clinical manifestations and indeterminate transthoracic echocardiographic (TTE) findings and were finally confirmed by transesophageal echocardiography (TEE).

Thyroid hormone-induced alterations of Ca2+-ATPase and phospholamban protein expression in cardiac sarcoplasmic reticulum

Alterations of cardiovascular function associated with various thyroid states have been studied. In hyperthyroidism left ventricular contractility and relaxation velocity were increased, whereas these parameters were decreased in hypothyroidism. The mechanisms for these changes have been suggested to include alterations in the expression and/or activity levels of various proteins; alpha-myosin heavy chain, beta-myosin heavy chain, beta-receptors, the guanine nucleotide-binding regulatory protein, and the sarcolemmal Ca2+-ATPase. All these cellular alterations may be associated with changes in the intracellular Ca2+ concentration. The most important regulator of intracellular Ca2+ concentration is the sarcoplasmic reticulum (SR), which serves as a Ca2+ sink during relaxation and as a Ca2+ source during contraction. The Ca2+-ATPase and phospholamban are the most important proteins in the SR membrane for muscle relaxation. The dephosphorylated phospholamban inhibits the SR Ca2+-ATPase through a direct interaction, and phosphorylation of phospholamban relieves the inhibition. In the present study, quantitative changes of Ca2+-ATPase and phospholamban expression and the functional consequences of these changes in various thyroid states were investigated. The effects of thyroid hormones on (1) SR Ca2+ uptake, (2) phosphorylation levels of phospholamban, (3) SR Ca2+-ATPase and phospholamban protein levels, (4) phospholamban mRNA levels were examined. Our findings indicate that hyperthyroidism is associated with increases in Ca2+-ATPase and decreases in phospholamban levels whereas opposite changes in these proteins occur in hypothyroidism.

Thyroid hormone-induced alterations of ryanodine and dihydropyridine receptor protein expression in rat hear

Thyroid hormone-induced cellular dysfunctions may be associated with changes in the intracellular Ca2+ concentration. The ryanodine receptor, a Ca2+ release channel of the SR, is responsible for the rapid release of Ca2+ that activates cardiac muscle contraction. In the excitation-contaction coupling cascade, activation of ryanodine receptors is initiated by the activity of sarcolemmal Ca2+ channels, the dihydropyridine receptors. In hyperthyroidism left ventricular contractility and relaxation velocity were increased, whereas these parameters were decreased in hypothyroidism. The mechanisms for these changes have been suggested to include alterations in the expression and/or activity levels of various proteins. In the present study, quantitative changes of ryanodine receptors and the dihydropyridine receptors, and the functional consequences of these changes in various thyroid states were investigated. In hyperthyroid hearts, (3H)ryanodine binding and ryanodine receptor mRNA levels were increased, but protein levels of ryanodine were not changed significantly. However, the above parameters were markedly decreased in hypothyroid hearts. In case of dihydropyridine receptor, there were a significant increase in the mRNA and protein levels, and (3H)nitrendipine binding, whereas no changes were observed in these parameters of hypothyroid hearts. Our findings indicate that hyperthyroidism is associated with increases in ryanodine receptor and dihydropyridine receptor expression levels, which is well correlated with the ryanodine and dihydropyridine binding. Whereas opposite changes occur in ryanodine receptor of the hypothyroid hearts.