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OBJECTIVE: To establish a simple and sensitive method of high performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS) for the determination of glipizide in human plasma and to calculate the pharmacokinetic parameters and evaluate the bioequivalence of two glipizide preparations in healthy Chinese volunteers. METHODS: A two-periods, randomized, crossover trial design was used. Twenty-four subjects took the test and reference preparations at the dose of 5 mg, and glipizide plasma concentration was determined by HPLC-MS/MS. Pharmacokinetic parameters were calculated and bioequivalence was evaluated. RESULTS: The mean pharmacokinetic parameters of glipizide after adminstration of 5 mg of test or reference preparations were as follows: ρmax were (251.25±61.94) and (240.13±52.43) μg·L-1, t1/2 were (4.85±1.39) and (5.08±1.76) h, tmax were (3.35±1.22) and (3.38±1.35) h, and AUC0-tn were (1561.44±475.73) and (1588.82±507.40) μg·h·L-1, respectively. CONCLUSION: The HPLC-MS/MS method is sensitive and simple, and can be used for the determination of glipizide plasma concentration. Statistical analysis of the pharmacokinetic parameters in heathy subjects indicated that the two preparations of glipizide are bioequivalent.
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Background With the widely application of phacoemulsication for cataract,dry eye-associated symptoms,such as foreign body sensation and burning frequently occur after cataract surgery in some patients.Objective This study was to evaluate the repair effects of recombinant human epithelial growth factor (rhEGF) on ocular surface injuriy after phacomulsification. Methods This was a prospective study,and informed consent was obtained from each subject before the experiment.One hundreds and twenty eyes of 89 consecutive patients after phacomulsification for age-related cataract were collected and randomized into rhEGF group,hyaluronic acid group and control group and 40 eyes for each.RhEGF drops and hyaluronic acid drops were topically administered 4 times per day for consecutive 4 weeks after surgery in corresponding group,and no drops mentioned above was used in the control group.The 0.3％ ofloxacin eye ointment and tobramycin+dexamethasone drops were used as the element drops in all patients of each group.Corneal fluorescein staining score,tear film break-up time ( BUT),Schrimer Ⅰ test without topical anesthesia were performed 1 day before surgery and 1 day,1 week,2 weeks and 1 month after surgery.Results The demography and the relevant surface examinational outcomes were no significantly different among the rhEGF group,hyaluronic acid group and control group in preoperation (age:F =3.74; gender:x2 =0.615; corneal fluorescein staining:F =0.247 ; BUT:F =0.579 ; Schrimer Ⅰ test:F =0.475 ; all P＞ 0.05 ).With the prolong of the time,the corneal fluorescein staining scores and Schrimer Ⅰ test values appeared a early ascent and latterly decline,and the BUT value showed a early shorten and latterly restore,with a statistically significant differences among various time points( F时间 =6.754,6.079,6.233,P＜0.01 ).Meanwhile,statistically significant differences were found in the corneal fluorescein staining scores,Schrimer Ⅰ test values and BUT among these 3 groups (F分组 =4.953,4.511,4.071,P＜0.05 ).The corneal fluorescein staining scores in the rhEGF group were significantly lower than those in the hyaluronic acid group at 2 weeks and 1 month after operation(P=0.039,0.014),and the BUT values in the rhEGF group were significantly longer than ones in the hyaluronic acid group at 1 week and 2 weeks after operation (P =0.019,0.007).The Schrimer I test values were significantly reduced in the rhEGF group compared with hyaluronic acid group at 1 week,2 weeks and 1 month after operation (P=0.022,0.003,0.019). Conclusions RhEGF promotes the repair of the ocular surface injury in the patients with age-related cataract after phacomulsification.
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BackgroundReactive oxygen intermediate products lead to the oxidative injury of cells.Retinal pigment epithelial(RPE) cells produce lots of reactive oxygen intermediate products during the swallow of out disc,but how this procedure cause the persistent oxidative injury of RPE cells is poorly understood.Objective The present study was to evaluate the effect of non-lethal H2 O2 -induced persistent oxidative injury on RPE barrier in vitro.MethodsARPE-19 cell links were inoculated on 96 well plate at the density of 8×104 cells/L and the cell climbing slice of 24 well at the density of 4× 104 cells/L.The cells were cultured in DMEM/F12 medium,and the cells cultured for 24 hours in free-serum medium were used in the experiment.0-0.6 mmol/L of H2O2 were added into the medium.Cellular viability was assessed using 3- ( 4,5-dimethylthiazol-2-yl ) -5- ( 3-carboxymethoxyphenyl ) -2- ( 4-sulfophenyl ) 2H-tetrazolium(MTS) assays.Transepithelial electrical resistance (TER) was used to detect cell monolayer forming time after cultureinTrsnswellchamber.Thepermeabilityof cellmonolayer was examinedbyrhodamine isothiocyanate-dextran transepithelial flux,and immunofluorescence was used to investigate the distribution of the junction protein zonula occludens (ZO-1).ResultsThe total difference was found in the cell vitality(A490) among the different concentrations of H2 O2 ( F =991.501,P =0.000 ).Compared with 0 mmoL/L H2 O2 group,the A490 values was gradually lowed from 0.20 mmol/L H2O2 group to 0.60 mmol/L H2O2 group (P ＜ 0.05 ).H2O2 at the concentrations of ＞0.20 mmol/L lowed the viability of RPE cells.The TER value was ( 24.9 ± 1.3 ) Ω · cm2 in 11 days,( 17.8± 1.4)Ω · cm2 in 7 days after inoculation on transwell chamber,showing a significant difference between them (t=5.228,P=0.014).RPE formed the stable tight junction on day 15 with the TER value (25.9±0.9 ) Ω · cm2.The leakage amount ( relative fluorescence intensity ) of the dextran was 255.39 ± 16.44 in non-H2 O2 control group,exhibiting a significant lowing in comparison with free-cell blank group (433.08±51.53)( t =12.515,P =0.006 ),and that of H2 O2 group was significant increased in comparison with non-H2 O2 control group ( t =14.412,P=0.005).Immunofluyorescence assay showed intact intercellular ZO-1 junction in non-H2O2 control group,but the breakage of ZO-1 junction was seen in H2O2 group.ConclusionsThe results indicate that non-lethal H2O2 can destroy RPE barrier and further lead to the persistent oxidative injury of RPE cells.
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<p><b>BACKGROUND</b>There are definite gender differences in patients with macular holes. Menopausal women over 50 years are most affected. We aimed to observe the effect of estrogen on collagen gel contraction by cultured human retinal glial cells. It is speculated that estrogen could strengthen the tensile stress of the macula by maintaining the correct morphology and contraction.</p><p><b>METHODS</b>Estrogen was used to determine its effects on collagen gel contraction, and its function was measured using morphological changes in cells. Human retinal glial cells were cultured in collagen solution. The cells were then exposed to collagen gels and the degree of contraction of the gel was determined.</p><p><b>RESULTS</b>Estrogen at differing concentrations had no effect on the growth of human retinal glial cells. However, after exposed to collagen gel block, less contraction was noted in the estrogen-treated group than in the control group.</p><p><b>CONCLUSIONS</b>Estrogen can inhibit collagen gel contraction by glial cells. These results suggest a mechanism for macular hole formation, which is observed in menopausal females.</p>