PURPOSE: To investigate the effects of dipyridamole (DPD) on the production of reactive oxygen species (ROS) and oxidative stress in cultured human trabecular meshwork cells (HTMC). METHODS: Antioxidant activity of DPD was determined by DPPH assay. Primarily cultured HTMC were exposed to 0, 20, and 50 microm DPD using serum-deprived media. The effect of DPD on the production of ROS was assessed with the DCHFDA assay. The effect of DPD on the t-butyl hydroperoxide (tBHP)-induced oxidative stress was assessed with resazurin assay. RESULTS: DPD showed significant antioxidant activity. DPD significantly decreased the production of ROS (p < 0.05) and improved cellular activity significantly after treatment with t-BHP (p < 0.05). DPD did not affect the generation of nitric oxides. CONCLUSIONS: DPD suppressed the formation of ROS and possessed cytoprotective activity against the oxidative stress in HTMC.
Dipyridamole ; Humans ; Oxazines ; Oxidative Stress ; Reactive Oxygen Species ; tert-Butylhydroperoxide ; Trabecular Meshwork ; Xanthenes

PURPOSE: To evaluate the protective effect of creatine on the survival of retinal ganglion cells after serum deprivation. METHODS: RGC-5 cells were exposed to 5 mM creatine with serum-free media for 4 days. Cellular survival and mitochondrial respiratory activity were measured with MTT assay and resazurin assay, respectively. Degree of apoptosis was evaluated with vital staining using acridine orange/Hoechest 33342 and flow cytometric analysis using annexin/PI, respectively. RESULTS: Creatine increased cellular survival of RGC-5 cells significantly after serum deprivation. Additionally, creatine increased mitochondrial respiratory activity and inhibited apoptosis of RGC-5 cells. CONCLUSIONS: The energy precursor creatine increased survival of retinal ganglion cells after serum deprivation. Creatine could be relevant for the cytoprotection of retinal ganglion cells.
Apoptosis ; Creatine ; Culture Media, Serum-Free ; Cytoprotection ; Oxazines ; Retinal Ganglion Cells ; Xanthenes

This paper specifically discusses the risk assessment on the pesticide residues in vegetables collected from traditional markets, big marts and departments in the southern part of Seoul. Vegetable samples were 6,583 cases from January to December in 2009. Monte-Carlo simulation was used to calculate the uncertainty for the risk index using pesticide residues, average dietary intake for vegetables and acceptable daily intake. Deterministic risk indexes were 7.33% of diethofencarb, 5.13% of indoxacarb, 3.96% of EPN, 3.92% of diniconazole and 3.09% of chlorothalonil, respectively. And other pesticides were below 3%. Distributions of risk indexes obtained by the Monte-Carlo simulations were similar to the deterministic values, even though the confidence intervals for 95% were very wide. We confirmed that health risks caused by eating vegetables exceeded maximum residue limits of pesticide are very low and the population is generally safe, judging from the risk indexes located between 0.07 to 9.49%.
Eating ; Korea ; Nitriles ; Oxazines ; Pesticide Residues ; Pesticides ; Phenylcarbamates ; Risk Assessment ; Triazoles ; Uncertainty ; Vegetables

Animals ; Humans ; Oxazines ; metabolism ; Phenylpropionates ; metabolism ; Receptors, Cytoplasmic and Nuclear ; agonists ; antagonists & inhibitors ; Thiazolidinediones ; metabolism ; Transcription Factors ; agonists ; antagonists & inhibitors

AIMTo assess that metabolic status of spermatozoa could provide a useful tool for evaluation of semen quality.

METHODSThe accuracy of the spectrophotometric application of the resazurin reduction assay was assessed using receiver operating characteristic (ROC) analysis.

RESULTSAreas under ROC curves (AUC) for motile sperm concentration and sperm index (SI) (sperm concentration multiplied by the square root of percentage sperm motility multiplied by the percentage normal sperm morphology) were 0.922. The best discrimination between poor and good semen samples according to the SI was achieved at a cut-off point of A610 = 0.209, where high sensitivity (94.1%) and specificity (91.7%) were calculated. The assay was less accurate when motile sperm concentration was used as the criterion value, yielding sensitivity of 88.2% and specificity of 87.5%, respectively. Likelihood ratios (LR) indicate that absorbances lower than 0.209 were at least 11.3 times as likely to be found in good semen samples than those in poor according to the SI, whereas in the case of motile sperm concentration, the LR was calculated to be 7.06.

CONCLUSIONThese results show that the resazurin reduction assay combined with spectrophotometry is an accurate method of assessing the quality of boar semen.

Animal Husbandry ; Animals ; Area Under Curve ; Male ; Oxazines ; pharmacokinetics ; pharmacology ; Semen ; physiology ; Sperm Motility ; Swine ; Xanthenes ; pharmacokinetics ; pharmacology

PURPOSE: The aim of this in vitro study was to investigate the adhesion of initial colonizer, Streptococcus sanguis, on resin, titanium and zirconia under the same surface polishing condition. MATERIALS AND METHODS: Specimens were prepared from Z-250, cp-Ti and 3Y-TZP and polished with 1 microm diamond paste. After coating with saliva, each specimen was incubated with Streptococcus sanguis. Scanning electron microscope, crystal violet staining and measurement of fluorescence intensity resulting from resazurin reduction were performed for quantifying the bacterial adhesion. RESULTS: Surface of resin composite was significantly rougher than that of titanium and zirconia, although all tested specimens are classified as smooth. The resin specimens showed lower value of contact angle compared with titanium and zirconia specimens, and had hydrophilic surfaces. The result of scanning electron microscopy demonstrated that bound bacteria were more abundant on resin in comparison with titanium and zirconia. When total biofilm mass determined by crystal violet, absorbance value of resin was significantly higher than that of titanium or zirconia. The result of relative fluorescence intensities also demonstrated that the highest fluorescence intensity was found on the surface of resin. Absorbance value and fluorescence intensity on titanium was not significantly different from those on zirconia. CONCLUSION: Resin specimens showed the roughest surface and have a significantly higher susceptibility to adhere Streptococcus sanguis than titanium and zirconia when surfaces of each specimen were polished under same condition. There was no significant difference in bacteria adhesion between titanium and zirconia in vitro.
Bacteria ; Bacterial Adhesion ; Biofilms ; Colon ; Diamond ; Electrons ; Fluorescence ; Gentian Violet ; Microscopy, Electron, Scanning ; Oxazines ; Saliva ; Streptococcus sanguis ; Titanium ; Xanthenes ; Zirconium

AIMTo develop a novel pulsatile drug delivery system of which the lag-time is controlled by an erodible plug (EP) and evaluate its release characteristics in vitro.

METHODSThe impermeable capsule body was prepared by fulfilling method and the drug tablet and the erodible plug were made by wet granulating compression. Tetramethylpyrazine phosphate (TMPP) pulsincap capsule was prepared by sealing the drug tablet and fillers inside the impermeable capsule body with the EP. The influence factors on the lag-time such as the EP pharmaceutical properties and the dissolution condition were investigated by dissolution testing.

RESULTSBoth the composition and the weight of EP influenced the lag-time of the tetramethylpyrazine phosphate pulsincap capsule significantly. The lag-time prior to the drug release was enhanced when the content of gel-forming excipient (hydroxypropylmethylcellulose, HPMC) in the EP or the weight of EP was increased. The hardness of EP showed minor influence on the lag-time. In addition, the lag-time was shortened when the paddle speed was higher, while the pH value of the dissolution medium exhibited no significant influence on it.

CONCLUSIONTo meet the chronotherapeutic requirements, a pulsatile drug delivery system with a suitable lag-time can be achieved by adjusting the composition and the EP weight.

Calcium Channel Blockers ; administration & dosage ; Capsules ; Delayed-Action Preparations ; Drug Delivery Systems ; Lactose ; analogs & derivatives ; Methylcellulose ; analogs & derivatives ; Oxazines ; Pyrazines ; administration & dosage ; Technology, Pharmaceutical

AIMTo prepare dilitazem hydrochloride delayed-onset, sustained release tablet, which can not only provide the delay in release start, but also the constant release rate after a lag time. To analyze release mechanism and investigate the effect of outershell compositions on release behavior.

METHODSThe delayed-onset, sustained release tablets were prepared by dry-compression coated technology. The release profiles of uncoated cores and presscoated tablets were compared. Two parameters, time-lag (Tlag) and release rate (k), were used to evaluate the influence of factors, such as the amount of hydroxypropylmethylcellulose (HPMC) and poly-vinyl-pyrrolidinone (PVP) K30, the viscosity of ethylcellulose (EC) and HPMC, and the compression load on diltazam hydrochloride (DIL) release. Higuchi equation and Peppa's equation were used to analyze release mechanism.

RESULTSWith the increase of HPMC amount or HPMC viscosity, Tlag was prolonged and k was decreased; With the increase of PVP K30 amount, Tlag was shortened and k was increased; EC viscosity and compression load above certain degree showed no effect on DIL release.

CONCLUSIONThe drug release from delayed-release tablet is controlled by erosion mechanism, Tlag is determined by the erosion rate of outer-shell.

Cellulose ; chemistry ; Delayed-Action Preparations ; Diltiazem ; administration & dosage ; Lactose ; analogs & derivatives ; chemistry ; Methylcellulose ; analogs & derivatives ; chemistry ; Oxazines ; Polyvinyls ; chemistry ; Pyrrolidinones ; chemistry ; Tablets ; administration & dosage ; chemistry ; Technology, Pharmaceutical ; Viscosity

OBJECTIVETo illustrate the effects of the site and method of liposuction on differentiation of human preadipocytes.

METHODSForty-two fatty samples were obtained with liposuction, which were then divided into four groups according to operation sites (abdomen, hip or extremity) and the methods (conventional negative-pressure or syringe method). Each sample was treated with collagenase I to release preadipocytes for in vitro culture. Affected by the differentiation-induced agents for 9 days or 28 days, the cultured adipocytes were stained with Nile red and observed under a fluorescent microscope. The differentiation rates were examined with flow cytometric analysis and the quantity of intracytoplasmic lipids was determined with oil red O staining. The results were analyzed with independent samples t-test (Mann-Whitney) using SPSS 10.0.

RESULTSThere was no statistical difference in differentiation at the 9th day or 28th day among the preadipocytes obtained from the abdomen, hip or extremity with the negative-pressure method. The preadipocytes from the abdomen differentiated more at the 28th day than the 9th day (P < 0.05), which was not observed in the hip or the extremity. The preadipocytes obtained from the abdomen with the negative-pressure method differentiated more than those with the syringe method (P < 0.05).

CONCLUSIONNo essential difference was found in preadipocyte differentiation among the liposuction sites, while the abdomen might have some superiority. The negative-pressure method of liposuction is the first option in future research of tissue engineering. The flow cytometric analysis is a convenient way to study preadipocyte differentiation.

Abdomen ; surgery ; Adipocytes ; cytology ; Adult ; Cell Differentiation ; Cells, Cultured ; Female ; Flow Cytometry ; Hip ; surgery ; Humans ; Lipectomy ; methods ; Male ; Microscopy, Fluorescence ; Middle Aged ; Oxazines

OBJECTIVETo study the influence of the sustained release excipient on the release rate of ginsenoside Rg1 and ginsenoside Rb1 in sustained-release tablet of Panax Notoginsenosides.

METHODThe release rate of ginsenoside Rg1 and ginsenoside Rb1 in different matrix tablets with different excipient (HPMC, EC), different viscosity of EC (RT-50, RT-100), different ratio of EC in matrix tablet were detected.

RESULTAll above different factors influence the release rate of ginsenoside Rg1 and ginsenoside Rb1 and brought them different release curve.

CONCLUSIONEmphasis should be laid on the different release characteristic of different active compounds in active fraction.

Chemistry, Pharmaceutical ; Delayed-Action Preparations ; Drugs, Chinese Herbal ; administration & dosage ; Excipients ; chemistry ; Ginsenosides ; chemistry ; Lactose ; analogs & derivatives ; chemistry ; Methylcellulose ; analogs & derivatives ; chemistry ; Oxazines ; Panax ; Plants, Medicinal ; Tablets