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1.
Molecules ; 28(22)2023 Nov 13.
Article in English | MEDLINE | ID: mdl-38005289

ABSTRACT

Analytical methods based on the mass balance approach were developed for the purity evaluation of tetracycline hydrochloride, a representative salt compound used in pure veterinary drug analysis. The purity assignment method was used to quantify individual classes of impurities via independent analytical techniques. The mass fraction of the free base or salt form contained in a high-purity organic compound with a hydrochloride salt can be determined. The chloride content by ion chromatography-conductivity detector (IC-CD) and general classes of impurities, including structurally related impurities by liquid chromatography-ultraviolet (LC-UV) detector, water by Karl Fischer (KF) coulometric titration, residual solvents by headspace sampler gas chromatography/mass spectrometry (HS-GC/MS), and non-volatiles by thermogravimetric analyzer (TGA), were considered to calculate the purity of the mass fraction. The chloride content of the salt compound can be considered the main impurity in the mass fraction of the free base in the salt compound. A purity assay using quantitative nuclear magnetic resonance (q-NMR) as a direct determination method was performed to confirm the results of the mass balance method. The assigned purities of the tetracycline free form and its salt form in mass fraction were (898.80 ± 1.60) mg/g and (972.65 ± 1.58) mg/g, respectively, which are traceable to the international system of units (SI). Thus, the procedure for evaluating the purity of the free base and salt forms in the salt compound is newly demonstrated in this study.


Subject(s)
Chlorides , Tetracycline , Chromatography, Liquid/methods , Gas Chromatography-Mass Spectrometry
2.
Toxicol In Vitro ; 65: 104813, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32119999

ABSTRACT

Phototoxicity due to dermally impregnated compounds exposed to ultraviolet radiation is associated with skin inflammation. The phototoxicity potential of active substances applied to the skin should be evaluated. Pigments are widely used for tattoos, and hypersensitivity reactions, such as photoallergic dermatitis, are possible tattoo-related complications. However, the phototoxicity of these chemicals is not well known. In this study, we evaluated the phototoxicity potential of six tattoo pigments, cadmium sulfide, carbazole, cadmium selenide, mercury (II) sulfide, chromium oxide, and cobalt aluminate, using in vitro methods-3 T3 neutral red uptake (NRU) phototoxicity test (PT) and a 3D human reconstructed skin model (EpiDerm). The validated 3 T3 NRU PT indicated the phototoxicity potential of carbazole and cadmium sulfide. The 3D human skin model confirmed that only carbazole was phototoxic. The 3 T3 NRU PT data corresponded well with those from the 3D skin model and suggested the need to employ several test systems for final phototoxicity assessment. In addition to the results obtained using 3 T3 NRU PT, further testing on 3D skin models may better reflect the bioavailability of a given chemical in the skin.


Subject(s)
Coloring Agents/toxicity , Dermatitis, Phototoxic , Tattooing/adverse effects , Ultraviolet Rays , Aluminum Compounds/toxicity , Animal Testing Alternatives , Animals , BALB 3T3 Cells , Biological Assay , Cadmium Compounds/toxicity , Carbazoles/toxicity , Chromium Compounds/toxicity , Cobalt/toxicity , Humans , In Vitro Techniques , Mercury Compounds/toxicity , Mice , Neutral Red/metabolism , Selenium Compounds/toxicity , Skin/metabolism , Sulfides/toxicity
3.
Ther Innov Regul Sci ; 53(2): 233-242, 2019 03.
Article in English | MEDLINE | ID: mdl-29888622

ABSTRACT

Globalization of the pharmaceutical industry has continued over the past few decades, and various regulatory authorities have put considerable effort into harmonizing and standardizing drug regulations. However, the regulatory practices of each regulatory authority, in addition to local differences in ethnic, social, and cultural backgrounds, create discrepancies in risk/benefit assessments, regulatory decisions, and drug label information in various countries. This study examines discrepancies in the label information for direct oral anticoagulants approved in the US, Europe, Korea, and Japan and reviews the causes of those discrepancies, focusing on regulatory practices. Although the label information for each direct oral anticoagulant in all 4 regions was supported by the same global, pivotal clinical data, it differed depending on regulatory authorities' judgments about the risk/benefit balance, which were based on their own requirements, regulations, perspectives on making regulatory decisions, and regulatory approval experiences, in addition to their review of the scientific data. In particular, the Korean Ministry of Food and Drug Safety and Japanese Pharmaceuticals and Medical Devices Agency have taken a comparatively conservative stance, with more emphasis on safety than on efficacy compared with regulatory authorities in western countries, because of the double threshold in their regulatory practice. Our findings suggest that drug label information in various regions will not be equal as long as differences in regulatory practice and non-regulatory factors exist among regulatory authorities. Also, those differences should be considered in order to streamline global drug discovery, development, and approval.


Subject(s)
Anticoagulants , Drug Labeling , Administration, Oral , Drug and Narcotic Control , Europe , Japan , Republic of Korea , United States
4.
PLoS One ; 13(5): e0196735, 2018.
Article in English | MEDLINE | ID: mdl-29782497

ABSTRACT

Many chemicals have been reported to induce phototoxicity. The absorbance of light energy within the sunlight range is a common characteristic of phototoxicity. The 3T3 NRU phototoxicity test (PT) in 3T3 mouse skin fibroblasts has been used to identify the phototoxic potential induced by excited chemicals after exposure to ultra violet (UV). However, as phototoxicity may occur in ocular cells, it is necessary to develop a more suitable test for cornea-derived cells. In this study, we attempted to establish a new in vitro PT method in rabbit corneal cell lines (SIRC). We evaluated five ophthalmic agents, ciprofloxacin, levofloxacin, lomefloxacin, norfloxacin, and tetracycline, for their cytotoxic potential and in vitro phototoxicity. The results obtained using 3D human corneal models revealed that the UV-induced eye tissue toxicity by the test substances showed good correlation with those obtained using the in vitro phototoxicity test. However, the results from the 3D PT for ciprofloxacin, norfloxacin, and tetracycline in the 3D human cornea model were only partially comparable. Therefore, we suggest the SIRC cell line as a new phototoxicity test model; however, a sequential testing strategy, such as 3D PT, was also proposed to obtain relevant information for topical eye agents.


Subject(s)
Biological Assay/methods , Cornea/drug effects , Dermatitis, Phototoxic/diagnosis , Ophthalmic Solutions/adverse effects , 3T3 Cells , Animals , Cell Line , Fibroblasts/drug effects , Humans , Mice , Rabbits , Ultraviolet Rays/adverse effects
5.
J Pharm Biomed Anal ; 129: 492-501, 2016 Sep 10.
Article in English | MEDLINE | ID: mdl-27497650

ABSTRACT

Nonsteroidal anti-inflammatory drugs (NSAIDs), which are globally prescribed, exhibit mainly anti-inflammatory and analgesic effects but also can cause adverse effects including gastrointestinal erosions, ulceration, bleeding, and perforation. The purpose of this study was to investigate surrogate biomarkers associated with the gastrointestinal (GI) damage caused by NSAID treatment using pattern recognition analysis of (1)H-nuclear magnetic resonance ((1)H NMR) spectra of rat urine. Urine was collected for 5h after oral administration of the following NSAIDs at low or high doses: acetylsalicylic acid (10 or 200mgkg(-1)), diclofenac (0.5 or 15mgkg(-1)), piroxicam (1 or 10mgkg(-1)), indomethacin (1 or 25mgkg(-1)), or ibuprofen (10, or 150mgkg(-1)) as nonselective COX inhibitors and celecoxib (10 or 100mgkg(-1)) as a COX-2 selective inhibitor. The urine was analyzed using 500MHz (1)H NMR for spectral binning and targeted profiling and the level of gastric damage was examined. The nonselective COX inhibitors caused severe gastric damage while no lesions were observed in the celecoxib-treated rats. The (1)H NMR urine spectra were divided into spectral bins (0.04ppm) for global profiling, and a total of 44 endogenous metabolites were assigned for targeted profiling. Multivariate data analyses were performed to recognize the spectral pattern of endogenous metabolites related to NSAIDs using partial least square-discrimination analysis (PLS-DA). The (1)H NMR spectra clustered differently according to gastric damage score in global profiling. In targeted profiling, the endogenous metabolites of citrate, allantoin, 2-oxoglutarate, acetate, benzoate, glycine, and trimethylamine N-oxide were selected as putative biomarkers for gastric damage caused by NSAIDs. These putative biomarkers might be useful for predicting the risk of adverse effects caused by NSAIDs in the early stage of drug development process.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Drug-Related Side Effects and Adverse Reactions/metabolism , Animals , Aspirin/adverse effects , Celecoxib/adverse effects , Cyclooxygenase 2 Inhibitors/adverse effects , Diclofenac/adverse effects , Gastric Mucosa/metabolism , Ibuprofen/adverse effects , Indomethacin/adverse effects , Least-Squares Analysis , Magnetic Resonance Imaging/methods , Magnetic Resonance Spectroscopy/methods , Male , Metabolomics/methods , Piroxicam/adverse effects , Rats , Rats, Sprague-Dawley
6.
Biomol Ther (Seoul) ; 23(4): 386-9, 2015 Jul.
Article in English | MEDLINE | ID: mdl-26157557

ABSTRACT

Sibutramine is an anorectic that has been banned since 2010 due to cardiovascular safety issues. However, counterfeit drugs or slimming products that include sibutramine are still available in the market. It has been reported that illegal sibutramine-contained pharmaceutical products induce cardiovascular crisis. However, the mechanism underlying sibutramine-induced cardiovascular adverse effect has not been fully evaluated yet. In this study, we performed cardiovascular safety pharmacology studies of sibutramine systemically using by hERG channel inhibition, action potential duration, and telemetry assays. Sibutramine inhibited hERG channel current of HEK293 cells with an IC50 of 3.92 µM in patch clamp assay and increased the heart rate and blood pressure (76 Δbpm in heart rate and 51 ΔmmHg in blood pressure) in beagle dogs at a dose of 30 mg/kg (per oral), while it shortened action potential duration (at 10 µM and 30 µM, resulted in 15% and 29% decreases in APD50, and 9% and 17% decreases in APD90, respectively) in the Purkinje fibers of rabbits and had no effects on the QTc interval in beagle dogs. These results suggest that sibutramine has a considerable adverse effect on the cardiovascular system and may contribute to accurate drug safety regulation.

7.
J Appl Toxicol ; 35(2): 205-18, 2015 Feb.
Article in English | MEDLINE | ID: mdl-24737281

ABSTRACT

An embryonic stem cell test (EST) has been developed to evaluate the embryotoxic potential of chemicals with an in vitro system. In the present study, novel methods to screen toxic chemicals during the developmental process were evaluated using undifferentiated human embryonic stem (hES) cells. By using surface marker antigens (SSEA-4, TRA-1-60 and TRA-1-81), we confirmed undifferentiated conditions of the used hES cells by immunocytochemistry. We assessed the developmental toxicity of embryotoxic chemicals, 5-fluorouracil, indomethacin and non-embryotoxic penicillin G in different concentrations for up to 7 days. While expressions of the surface markers were not significantly affected, the embryotoxic chemicals influenced their response to pluripotent ES cell markers, such as OCT-4, NANOG, endothelin receptor type B (EDNRB), secreted frizzled related protein 2 (SFRP2), teratocarcinoma-derived growth factor 1 (TDGF1), and phosphatase and tensin homolog (PTEN). Most of the pluripotent ES cell markers were down-regulated in a dose-dependent manner after treatment with embryotoxic chemicals. After treatment with 5-fluorouracil, indomethacin and penicillin G, we observed a remarkable convergence in the degree of up-regulation of development, cell cycle and apoptosis-related genes by gene expression profiles using an Affymetrix GeneChips. Taken together, these results suggest that embryotoxic chemicals have cytotoxic effects, and modulate the expression of ES cell markers as well as development-, cell cycle- and apoptosis-related genes that have pivotal roles in undifferentiated hES cells. Therefore, we suggest that hES cells may be useful for testing the toxic effects of chemicals that could impact the embryonic developmental stage.


Subject(s)
Embryonic Stem Cells/drug effects , Antigens, Surface/metabolism , Dose-Response Relationship, Drug , Fluorouracil/toxicity , Gene Expression Profiling , Humans , Indomethacin/toxicity , Penicillin G/toxicity , Real-Time Polymerase Chain Reaction , Toxicity Tests/methods
8.
Ultrasound Med Biol ; 38(12): 2143-50, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23062374

ABSTRACT

The sonodynamically induced selective antitumor effects of 5-aminolevulinic acid (5-ALA) on a C6 glioma that was implanted in a rat brain were evaluated. One week after the inoculation of the brains with the C6 rat glioma cells, glioma development was monitored using a 1.5 T MRI. Brains both with and without intravenous administration of 5-ALA (60 mg/kg body weight) or Radachlorin (40 mg/kg body weight) were insonated by a 1 MHz ultrasound at a dose of 2.65 W/cm(2). Irradiation was performed in a fractionated manner to avoid any thermal effects in the tissue due to the focused ultrasound; 16 min of irradiation were followed by a 3 min recess, then 4 min of resumed irradiation. Mean tumor sizes, measured after the rats were sacrificed 2 weeks post treatment, were 122.48 ± 39.64 mm(3) in sham-operated rats, 87.42 ± 21.40 mm(3) in rats receiving ultrasound without 5-ALA, 10.50 ± 8.20 mm(3) in rats receiving ultrasound with 5-ALA, and 56.42 ± 12.48 mm(3) in rats receiving ultrasound with Radachlorin. The tumor size was significantly smaller in the therapy group receiving sonodynamic 5-ALA than in any of the other groups (p < 0.05). This experimental rat model showed that sonodynamic therapy can be useful in the treatment of deep-seated malignant gliomas.


Subject(s)
Aminolevulinic Acid/therapeutic use , Antineoplastic Agents/therapeutic use , Brain Neoplasms/therapy , Glioma/therapy , Photosensitizing Agents/therapeutic use , Ultrasonic Therapy , Animals , Brain Neoplasms/pathology , Female , Glioma/pathology , Phantoms, Imaging , Rats , Rats, Sprague-Dawley
9.
Anal Chim Acta ; 722: 87-94, 2012 Apr 13.
Article in English | MEDLINE | ID: mdl-22444538

ABSTRACT

Non-steroidal anti-inflammatory drugs (NSAIDs) have side effects including gastric erosions, ulceration and bleeding. In this study, pattern recognition analysis of the (1)H-nuclear magnetic resonance (NMR) spectra of urine was performed to develop surrogate biomarkers related to the gastrointestinal (GI) damage induced by indomethacin in rats. Urine was collected for 5 h after oral administration of indomethacin (25 mg kg(-1)) or co-administration with cimetidine (100 mg kg(-1)), which protects against GI damage. The (1)H-NMR urine spectra were divided into spectral bins (0.04 ppm) for global profiling, and 36 endogenous metabolites were assigned for targeted profiling. The level of gastric damage in each animal was also determined. Indomethacin caused severe gastric damage; however, indomethacin administered with cimetidine did not. Simultaneously, the patterns of changes in their endogenous metabolites were different. Multivariate data analyses were carried out to recognize the spectral pattern of endogenous metabolites related to indomethacin using partial least square-discrimination analysis. In targeted profiling, a few endogenous metabolites, 2-oxoglutarate, acetate, taurine and hippurate, were selected as putative biomarkers for the gastric damage induced by indomethacin. These metabolites changed depending on the degree of GI damage, although the same dose of indomethacin (10 mg kg(-1)) was administered to rats. The results of global and targeted profiling suggest that the gastric damage induced by NSAIDs can be screened in the preclinical stage of drug development using a NMR based metabolomics approach.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Gastric Mucosa/drug effects , Indomethacin/pharmacology , Magnetic Resonance Spectroscopy , Animals , Anti-Inflammatory Agents, Non-Steroidal/metabolism , Discriminant Analysis , Indomethacin/metabolism , Least-Squares Analysis , Male , Metabolomics , Principal Component Analysis , Rats , Rats, Sprague-Dawley
10.
Toxicol Appl Pharmacol ; 249(2): 114-26, 2010 Dec 01.
Article in English | MEDLINE | ID: mdl-20804780

ABSTRACT

The primary objective of this study was to determine and characterize surrogate biomarkers that can predict nephrotoxicity induced by mercuric chloride (HgCl2) using urinary proton nuclear magnetic resonance (¹H NMR) spectral data. A procedure for (1)H NMR urinalysis using pattern recognition was proposed to evaluate nephrotoxicity induced by HgCl2 in Sprague-Dawley rats. HgCl2 at 0.1 or 0.75 mg/kg was administered intraperitoneally (i.p.), and urine was collected every 24 h for 6 days. Animals (n=6 per group) were sacrificed 3 or 6 days post-dosing in order to perform clinical blood chemistry tests and histopathologic examinations. Urinary ¹H NMR spectroscopy revealed apparent differential clustering between the control and HgCl2 treatment groups as evidenced by principal component analysis (PCA) and partial least square (PLS)-discriminant analysis (DA). Time- and dose-dependent separation of HgCl2-treated animals from controls was observed by PCA of ¹H NMR spectral data. In HgCl2-treated rats, the concentrations of endogenous urinary metabolites of glucose, acetate, alanine, lactate, succinate, and ethanol were significantly increased, whereas the concentrations of 2-oxoglutarate, allantoin, citrate, formate, taurine, and hippurate were significantly decreased. These endogenous metabolites were selected as putative biomarkers for HgCl2-induced nephrotoxicity. A dose response was observed in concentrations of lactate, acetate, succinate, and ethanol, where severe disruption of the concentrations of 2-oxoglutarate, citrate, formate, glucose, and taurine was observed at the higher dose (0.75 mg/kg) of HgCl2. Correlation of urinary (1)H NMR PLS-DA data with renal histopathologic changes suggests that ¹H NMR urinalysis can be used to predict or screen for HgCl2-induced nephrotoxicity.


Subject(s)
Acute Kidney Injury/chemically induced , Acute Kidney Injury/urine , Mercuric Chloride/toxicity , Mercuric Chloride/urine , Acute Kidney Injury/blood , Animals , Biomarkers/urine , Dose-Response Relationship, Drug , Magnetic Resonance Spectroscopy , Male , Mercuric Chloride/blood , Metabolomics , Rats , Rats, Sprague-Dawley , Time Factors
11.
Anal Chem ; 81(12): 4734-41, 2009 Jun 15.
Article in English | MEDLINE | ID: mdl-19462990

ABSTRACT

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to treat rheumatoid arthritis, osteoarthritis, acute pain, and fever. However, NSAIDs have side effects that include gastric erosions, ulceration, bleeding, and perforation, etc. Selective cyclooxygenase (COX)-2 inhibitors have been developed to avoid the adverse drug reaction of traditional NSAIDs. The COX-2 inhibitors have a different mechanism of action from nonselective COX inhibitors. In this study, pattern recognition analysis of the (1)H nuclear magnetic resonance (NMR) spectra of urine was performed to develop surrogate biomarkers related to the gastrointestinal (GI) damage induced by NSAIDs in rats. Urine was collected for 5 h after administering the following NSAIDs at high doses: celecoxib (133 mg kg(-1), p.o.), a COX-2-selective inhibitor; and indomethacin (25 mg kg(-1), p.o.) or ibuprofen (800 mg kg(-1), p.o.), nonselective COX inhibitors. The urine was analyzed using 600 M (1)H NMR for spectral binning and targeted profiling. The level of gastric damage in each animal was also determined. Indomethacin and ibuprofen caused severe gastric damage, but no lesions were observed in the celecoxib-treated rats. The (1)H NMR urine spectra were divided into spectral bins (0.04 ppm) for global profiling, and 36 endogenous metabolites were assigned for targeted profiling. Multivariate data analyses were carried out to recognize the spectral pattern of endogenous metabolites related to NSAIDs using partial least-squares discrimination analysis (PLS-DA). There were different clusterings of (1)H NMR spectra according to the gastric damage scores in global profiling. In targeted profiling, a few endogenous metabolites of allantoin, taurine, and dimethylamine were selected as putative biomarkers for the gastric damage induced by NSAIDs. The results of global and targeted profilings suggest that the gastric damage induced by NSAIDs can be screened in the preclinical stage of drug development using a current metabolomics study. In addition, the putative biomarkers might also be useful for predicting the risk of adverse effects caused by NSAIDs.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/toxicity , Magnetic Resonance Spectroscopy/methods , Metabolomics/methods , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Anti-Inflammatory Agents, Non-Steroidal/urine , Celecoxib , Cyclooxygenase 2 Inhibitors/metabolism , Cyclooxygenase 2 Inhibitors/toxicity , Cyclooxygenase 2 Inhibitors/urine , Ibuprofen/metabolism , Ibuprofen/toxicity , Ibuprofen/urine , Indomethacin/metabolism , Indomethacin/pharmacology , Indomethacin/toxicity , Least-Squares Analysis , Male , Pattern Recognition, Automated , Predictive Value of Tests , Pyrazoles/metabolism , Pyrazoles/toxicity , Pyrazoles/urine , Rats , Rats, Sprague-Dawley , Stomach/pathology , Sulfonamides/metabolism , Sulfonamides/toxicity , Sulfonamides/urine
12.
J Korean Neurosurg Soc ; 45(2): 112-4, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19274123

ABSTRACT

Clear cell sarcoma (CCS), also called malignant melanoma of soft parts, is a rare malignant soft tissue tumor and is often associated with tendons or aponeuroses. Most of CCS involve extremities, especially lower extremities, but a tumor occurring in the trunk is rare. We report an extremely rare case of CCS originated in the upper thoracic back muscle. To our knowledge, this case is the second report of CCS of the back muscle.

13.
J Toxicol Environ Health A ; 72(21-22): 1352-68, 2009.
Article in English | MEDLINE | ID: mdl-20077207

ABSTRACT

The primary objective of this study was to develop exposure biomarkers that "correlate with the endocrine-disrupting effects induced by methoxyclor (MTC), an organochlorine pesticide, using" urinary (1)H nuclear magnetic resonance (NMR) spectral data. Exposure biomarkers play an important role in risk assessment. MTC is an environmental endocrine disruptor with estrogenic, anti-estrogenic, and anti-androgenic properties. A new approach of proton nuclear magnetic resonance ((1)H NMR) urinalysis using pattern recognition was proposed for exposure biomarkers of MTC in female rats. The endocrine disruptor was expected to induce estrogenic effects in a dose dependent manner which, was confirmed by the uterotrophic assay. MTC [50, 100, or 200 m g/kg/d, orally (p.o.) or subcutaneously (s.c.)] was administered to ovariectomized female Sprague-Dawley (SD) rats for 3 d consecutively and urine was collected every 24 h. The animals were sacrificed 24 h after the last dose. All animals treated orally with MTC showed a significant increase in uterine and vaginal weight at all doses. However, in the s.c. route, only a high dose of 200 mg MTC/kg induced a significant increase in uterine and vaginal weight. (1)H NMR spectroscopy revealed evident separate clustering between pre- and post-treatment groups using global metabolic profiling through principal component analysis (PCA) and partial least square (PLS) discrimination analysis (DA) after different exposure routes. With targeted profiling, the endogenous metabolites of acetate, alanine, benzoate, lactate, and glycine were selected as putative exposure biomarkers for MTC. Data suggest that the proposed putative exposure biomarkers may be useful in a risk assessment of the endocrine-disrupting effects produced by MTC.


Subject(s)
Insecticides/toxicity , Metabolomics/methods , Methoxychlor/toxicity , Administration, Oral , Animals , Dose-Response Relationship, Drug , Endocrine Disruptors/administration & dosage , Endocrine Disruptors/chemistry , Endocrine Disruptors/toxicity , Female , Gene Expression Profiling , Injections, Subcutaneous , Insecticides/administration & dosage , Insecticides/chemistry , Methoxychlor/administration & dosage , Methoxychlor/chemistry , Molecular Structure , Rats , Rats, Sprague-Dawley , Risk Factors
14.
J Sep Sci ; 31(15): 2820-6, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18666167

ABSTRACT

A simple and direct analysis using column-switching HPLC method was developed and validated for the quantification of active metabolites of sibutramine, N-mono-desmethyl metabolite (metabolite 1, M1) and N-di-desmethyl metabolite (metabolite 2, M2) in the serum of rats administered sibutramine HCl (5.0 mg/kg, p.o.). Rat serum was directly injected onto the precolumn without sample prepreparation step following dilution with mobile phase A, i. e., methanol-ACN-20 mM ammonium phosphate buffer (pH 6.0 with phosphoric acid) (8.3:4.5:87.2 by volume). After the endogenous serum components were eluted to waste, the system was switched and the analytes were eluted to the trap column. Active metabolites M1 and M2 were then back-flushed to the analytical column for separation with mobile phase B, i. e., methanol-ACN-20 mM ammonium phosphate buffer (pH 6.0 with phosphoric acid) (35.8:19.2:45 by volume) and detected at 223 nm. The calibration curves of active metabolites M1 and M2 were linear in the range of 0.1-1.0 microg/mL and 0.15-1.8 microg/mL. This method was fully validated and shown to be specific, accurate (10.4-10.7% error), and precise (1.97-8.79% CV). This simple and rapid analytical method using column-switching appears to be useful for the pharmacokinetic study of active metabolites (M1 and M2) of sibutramine.


Subject(s)
Cyclobutanes/blood , Administration, Oral , Animals , Calibration , Chromatography, High Pressure Liquid/instrumentation , Chromatography, High Pressure Liquid/methods , Cyclobutanes/administration & dosage , Male , Molecular Structure , Rats , Rats, Sprague-Dawley , Reproducibility of Results , Sensitivity and Specificity , Stereoisomerism
15.
Neurosci Lett ; 428(1): 33-7, 2007 Nov 20.
Article in English | MEDLINE | ID: mdl-17945420

ABSTRACT

It is well established that the reinforcing effect of drugs of abuse is linked to the mesolimbic dopamine (DA) system. Morphine produces an increase in DA release in the brain, which may provide positive reinforcement contributing to the development of motivational aspects of drug-seeking and maintenance behavior. Several studies suggest that the GABA receptor system may play a significant role in the modulating the mesolimbic DA system. The purpose of this study was to investigate potential roles for GABA agonists in morphine self-administration behavior. Male Sprague-Dawley rats were trained to self-administrated morphine (0.1 mg/kg per injection) during daily 1-h sessions under a fixed ratio 1 schedule. Rats received an intravenous injection of the selective GABA(B) antagonist SCH 50911 (2.0 mg/kg) or an intraperitoneal injection of the GABA(A) antagonist bicuculline (1.0 mg/kg), immediately followed by either an intraperitoneal injection of baclofen (1.25 or 1.8 mg/kg) or muscimol (0.5 or 1.0 mg/kg, i.p.), 30 min prior to the start of test session. Results showed that pretreatment with baclofen or muscimol reduced morphine-maintenance response in a dose-dependent fashion and that baclofen and muscimol effects were reversed by injections of SCH 50911 and bicuculline, respectively. These data suggest that activation of both GABA(A) and GABA(B) receptors may be effective in suppressing the reinforcing effects of morphine.


Subject(s)
Conditioning, Operant/drug effects , Morphine/administration & dosage , Narcotics/administration & dosage , Receptors, GABA/physiology , Reinforcement, Psychology , Animals , Behavior, Animal/drug effects , Bicuculline/pharmacology , Dose-Response Relationship, Drug , Drug Interactions , GABA Agonists/pharmacology , GABA Antagonists/pharmacology , Male , Morpholines/pharmacology , Muscimol/pharmacology , Rats , Rats, Sprague-Dawley , Self Administration
16.
J Refract Surg ; 23(4): 362-7, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17455831

ABSTRACT

PURPOSE: To assess the efficacy of the ultrasound biomicroscopic (UBM) method in estimating the sulcus-to-sulcus horizontal diameter for Visian Implantable Contact Lens (ICL, model V4) length determination to obtain optimal ICL vault. METHODS: The results of postoperative ICL vaults in 30 eyes of 18 patients were retrospectively analyzed. In 17 eyes, ICL length was determined using the conventional method, and in 13 eyes, ICL length was determined using the UBM method. The UBM method was carried out by measuring the sulcus to limbus distance on each side by 50 MHz UBM and adding the white-to-white diameter by caliper or Orbscan. The ICL vaults were measured using the UBM method at 1 and 6 months postoperatively and the results were compared between the two groups. Ideal ICL vault was defined as vault between 250 and 750 microm. The relation between the ICL vault, footplate location, and ICL power was also investigated. RESULTS: In the UBM method group, ICL vault was within the ideal range in all 13 (100%) eyes at 1 and 6 months postoperatively, whereas in the conventional method group, 10 (58.8%) eyes showed ideal vault at 1 month postoperatively (P = .01) and 9 (52.9%) eyes showed ideal vault at 6 months postoperatively (P < .01). The ideal ICL footplate location was achieved in the ciliary sulcus in 11 (84.6%) eyes of the UBM method group and 10 (64.7%) eyes of the conventional method group. However, the differences between the two groups were not statistically significant. The ICL vault was not significantly affected by the ICL power. CONCLUSIONS: Implantable Contact Lens length determined by the UBM method achieved significantly more ideal ICL vault than that of the conventional white-to-white method. The UBM method is superior to the conventional method in terms of predicting the sulcus-to-sulcus horizontal diameter for ICL length determination.


Subject(s)
Lens Implantation, Intraocular , Lens, Crystalline/diagnostic imaging , Lenses, Intraocular , Microscopy, Acoustic , Adult , Equipment Design , Eyeglasses , Humans , Interferometry , Middle Aged , Models, Theoretical , Optics and Photonics , Retrospective Studies , Visual Acuity
17.
J Pediatr Ophthalmol Strabismus ; 43(5): 285-8, 2006.
Article in English | MEDLINE | ID: mdl-17022162

ABSTRACT

PURPOSE: To investigate the factors influencing visual development in blepharophimosis-ptosis-epicanthus inversus syndrome. MATERIALS AND METHODS: The study population comprised 20 patients with blepharophimosis-ptosis-epicanthus inversus syndrome who were referred for an oculoplastic opinion. The ocular examination included measurement of Snellen visual acuity, cycloplegic refraction, ocular movements and alignment, and the presence of amblyopia. Patients were treated with spectacle correction, occlusion therapy, strabismus surgery, and oculoplastic surgery if necessary. Minimum follow-up was 2 years. RESULTS: Nine (45%) patients had amblyopia; 5 (25%) of these patients had unilateral amblyopia and 4 (20%) had bilateral amblyopia. Six (67%) patients with amblyopia had a significant coexisting strabismus. A significant strabismus was present in 11 (55%) patients; 6 (55%) of these patients had unilateral or bilateral amblyopia. Patients with strabismus were more likely to have amblyopia than those without. A total of 14 (70%) patients had refractive error; 6 (43%) of these patients had amblyopia. CONCLUSIONS: Patients with blepharophimosis-ptosis-epicanthus inversus syndrome had a high rate of amblyopia, especially bilateral amblyopia. Patients with strabismus were more likely to have amblyopia than those without. Patients also had a high incidence of refractive errors.


Subject(s)
Amblyopia/complications , Blepharophimosis/complications , Blepharoptosis/complications , Eyelids/abnormalities , Refractive Errors/complications , Strabismus/complications , Adult , Amblyopia/physiopathology , Blepharophimosis/physiopathology , Blepharoptosis/physiopathology , Female , Humans , Infant, Newborn , Male , Refraction, Ocular , Refractive Errors/physiopathology , Retrospective Studies , Risk Factors , Strabismus/physiopathology , Syndrome , Visual Acuity
18.
Ophthalmic Plast Reconstr Surg ; 21(5): 349-52, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16234696

ABSTRACT

PURPOSE: To report on the first case of malignant proliferating trichilemmal tumor (PTT) on the eyelid, and to describe the clinical and histopathologic findings. METHODS: Interventional case report and literature review. RESULTS: A 42-year-old woman presented with a 2-year history of a firm, 3 x 2 cm lower eyelid mass. The mass was excised with the frozen section control. The defect in the lower eyelid was reconstructed with modified Hughes tarsoconjunctival flap and skin graft from the left postauricular area. Histopathologic examination revealed the proliferation of outer hair sheath epithelium with multiple central areas of trichilemmal keratinization. The presence of marked cellular atypia and frequent mitoses indicated the malignant transformation. CONCLUSIONS: Malignant PTT has not yet been reported on the eyelid. Malignant PTT should be included in the differential diagnosis for eyelid tumors.


Subject(s)
Eyelid Neoplasms/pathology , Hair Diseases/pathology , Hair Follicle , Skin Diseases/pathology , Adult , Blepharoplasty , Eyelid Neoplasms/surgery , Female , Hair Diseases/surgery , Humans , Skin Diseases/surgery , Surgical Flaps
19.
Toxicology ; 216(2-3): 140-6, 2005 Dec 15.
Article in English | MEDLINE | ID: mdl-16182432

ABSTRACT

UNLABELLED: The protective effect of an antioxidant, Vitamin E (dl-alpha-tocopherol, 100 mg/kg/day, 8 days p.o. in vivo and 10 and 50 microM in vitro) was tested against PCB-induced neurotoxicity. IN VIVO STUDIES: Microdialysis was used to investigate changes in the striatal extracellular dopamine level and in p-nNOS expression in PCB-treated (Aroclor 1254, 10 microg/ml, 2 microl/min, 5 h; 6 microg was infused by microdialysis probe) rats. IN VITRO STUDIES: Cell viability and levels of p-nNOS expression were observed in PCB-treated (Aroclor 1254, 5 microg/ml) immortalized dopaminergic cell line (CATH.a cells). RESULTS: Treatment with PCB: (1) decreased the extracellular dopamine level in rat striatum, (2) increased p-nNOS expression both in rat striatal tissue and in CATH.a cells, (3) reduced the cell viability of, and (4) increased LDH release by CATH.a cells. However, Vitamin E showed a protective effect against PCB-induced toxicity and downregulation of the extracellular dopamine level. These results indicate that Vitamin E may have neuroprotective effects by inhibiting PCB-induced nNOS phosphorylation.


Subject(s)
Dopamine/metabolism , Endocrine Disruptors , Neurotoxicity Syndromes/prevention & control , Nitric Oxide Synthase Type I/metabolism , Polychlorinated Biphenyls/toxicity , Vitamin E/pharmacology , Administration, Oral , Animals , Cell Culture Techniques , Cell Survival/drug effects , Chromatography, High Pressure Liquid , Corpus Striatum/drug effects , Corpus Striatum/metabolism , Immunoblotting , Male , Microdialysis , Neurotoxicity Syndromes/etiology , Neurotoxicity Syndromes/metabolism , Nitric Oxide Synthase Type I/drug effects , Phosphorylation/drug effects , Polychlorinated Biphenyls/antagonists & inhibitors , Rats , Rats, Sprague-Dawley , Time Factors , Up-Regulation/drug effects , Vitamin E/administration & dosage , Vitamin E/therapeutic use
20.
Behav Brain Res ; 158(1): 143-57, 2005 Mar 07.
Article in English | MEDLINE | ID: mdl-15680202

ABSTRACT

Current evidence suggests that ginsenosides inhibit methamphetamine (MA)-induced changes in behavior, but the precise mechanisms that underlie this effect are yet to be determined. We examined the role of adenosine receptors in the ginsenoside-induced changes in hyperlocomotion and conditioned place preference (CPP) in mice that occurred in response to administration of MA (2 mg/kg, i.p. x 1 or 2 mg/kg, i.p. x 6). Changes in circling behavior paralleled changes in CPP in the presence of MA. Pre-treatment with ginsenosides (50 or 150 mg/kg, i.p.) attenuated the MA-induced circling behavior and CPP. This attenuation was reversed by the adenosine A2A receptor antagonist 1,3,7-trimethyl-8-(3-chrostyryl)xanthine (CSC; 0.5 and 1.0 mg/kg) in a dose-dependent manner, but neither the adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dimethylxanthine (CPT; 0.5 and 1.0 mg/kg) nor the A2B receptor antagonist alloxazine (ALX; 1.5 and 3.0 mg/kg) had any such effect. MA-induced increases in activator protein (AP)-1 DNA binding activity, Fos-related antigen immunoreactivity (FRA-IR), proenkephalin mRNA expression, and proenkephalin-like immunoreactivity were reduced consistently in the striatum of animals that were pretreated with ginsenosides. These reductions were largely prevented by CSC, but not by CPT or ALX. Our results suggest that the stimulation of A2A receptors by ginsenosides attenuates the changes in behavior and the increases in AP-1 DNA binding activity, FRA-IR, and proenkephalin gene expression in mouse striatum that are induced by MA.


Subject(s)
Behavior, Animal/drug effects , Central Nervous System Stimulants/pharmacology , Corpus Striatum/drug effects , Enkephalins/metabolism , Ginsenosides/pharmacology , Methamphetamine/pharmacology , Protein Precursors/metabolism , Receptor, Adenosine A2A/physiology , Transcription Factor AP-1/metabolism , Adenosine A2 Receptor Antagonists , Analysis of Variance , Animals , Blotting, Northern/methods , Cell Count/methods , Conditioning, Operant/drug effects , Corpus Striatum/physiology , Dose-Response Relationship, Drug , Drug Administration Schedule , Drug Interactions , Electrophoretic Mobility Shift Assay/methods , Enkephalins/genetics , Gene Expression/drug effects , Immunohistochemistry/methods , Male , Mice , Mice, Inbred C57BL , Oncogene Proteins v-fos/metabolism , Protein Precursors/genetics , RNA, Messenger/metabolism , Stereotyped Behavior/drug effects , Teprotide/pharmacology , Time Factors
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