Objective To determine the best threshold value of hemoglobin A2 (HbA2) for diagnosis of β-thalassemia (β-thal) carriers by using high performance liquid chromatography (HPLC), and to improve the application value of HbA2 as a diagnostic index for β-thal carriers to reduce the rates of missed diagnosis and misdiagnosis. Methods Using reverse dot blot (RDB) as a gold standard method, HbA2 results of 1 007 β-thal carriers and 606 normal controls in the past two years determined by HPLC were divided into true positive, false positive, true negative, and false negative based on the different threshold values of HbA2 results. Then, the evaluation indexes such as sensitivity, specificity, positive and negative likelihood ratio, and Youden’s index were evaluated. Next, the receiver operator characteristic (ROC) curve was drawn to determine the best threshold value of HbA2 for diagnosis of β-thal carriers by HPLC. Results If ≥4.0% was taken as the threshold value of HbA2 for diagnosis of β-thal carriers by HPLC, the evaluation indexes values were shown as follows: sensitivity 99.21%, specificity 99.34%, positive likelihood ratio 150.30, negative likelihood ratio 0.008, and Youden’s index 0.99. The Youden’s index was better than the other threshold values, and the corresponding tangent point was the peak point of the ROC curve. Conclusion When ≥4.0% serves as the best threshold value of HbA2 for diagnosis of β-thal carriers using HPLC, integrated evaluation performance of the corresponding sensitivity and specificity is the most ideal, and the authenticity of the diagnostic test is the best.
Objective To study the distribution and concentration of meropenem in rabbit bile. Methods The rabbits were cannulated with a silicone tube in the common bile duct and the blank bile was collected. The rabbits were then administered intravenously with meropenem. Multiple bile samples (1.5 ml) were collected at different phases after the administrations. According to requirement of the high performance liquid chromatography (HPLC), the specificity test was undertook. The blank bile was then mixed with meropenem and mobile phase, respectively, in order to obtain a series of bile samples at different concentrations ranging from 0.5 to 500 μg/ml. The samples were analyzed with HPLC and the chromatographic peak area of meropenem contents were quantitated through external reference method. The linear regression equation was used to analyzed the relationship between the drug concentrations and the chromatographic peak areas. The bile samples that were collected after drug administrations were pretreated and the chromatographic peak areas were assayed by the liquid chromatograph. The bile concentrations were then calculated according to the regression equation, and the concentration-time distribution of meropenem in the bile was obtained ultimately. Results The specificity test indicated the bile dopant peak and the meropenem chromatographic peak were well-separated under chromatographic condition of the mobile phase. The standard curve regression equation was S=2 209.10C-1 251.34, r=0.999 9, and minimum quantitation limit of meropenem was 0.5 μg/ml. After a single i.v. administration of 75 mg/kg of meropenem in each rabbit, drug concentrations reached (38.36±14.17) μg/ml immediately in bile， which significantly exceeded the minimum inhibitory concentrations (MIC90) for most gram negatives, which range from 0.031 to 2 μg/ml. The bile concentration of meropenem decreased quickly over time, and meropenem was eliminated completely in rabbit bile 3 hours after intravenous injection. Conclusion Meropenem could achieve adequate bile concentration for the treatment of biliary tract infection due to susceptible bacteria. However, because of its rapid biliary elimination, meropenem should be used in shorter interval time.
ObjectiveTo study the effects of different penetration enhancers on the transdermal penetration of Miao medicine named Diploclisia affinis. MethodsImproved Franz diffusion cell was adopted as the apparatus for in vitro mouse' skin permeation. The kinetic parameters of percutaneous absorption, such as penetration rate, enhancing rate (ER), and lag time (Tlag) were determined by high performance liquid chromatography. Azone, oleic acid (OA) and borneol were investigated for percutaneous absorption effects. ResultsThe penetration rates of the medicine with 3% azone, OA and borneol added were respectively (214.1872±13.5690), (227.5544±9.8490), and (168.1187±21.5640) μg/(cm2·h), and the ER was 1.61, 1.71, and 1.26 compared with the penetration rate of that with nothing added. The Tlag was 2.1081, 1.8256, and 2.9655 hours. ConclusionAll the penetration enhancers can increase significantly the absorption of Miao medicine named Diploclisia affinis, especially 3% OA is the best, but 3% borneol may make the Tlag longer.
ObjectiveTo determinate the concentration of isonicotinyl hydrazide (INH) in the hydrothorax and thereby increase the drug concentration of the hydrothorax to enhance the anti-tuberculosis efficacy through experiments. MethodsBetween February and June 2009, we used high performance liquid chromatography (HPLC) to determinate the concentration of INH in the hydrothorax of tuberculosis (TB) patients. The separation of sample was performed on Agilent ZORBAX SB-C18 (5 μm, 4.6 mm×2.5 mm) column with a fixed sample injection volume of 20 μL. The mobile phase was methanol-water (20︰80) at a flow rate of 1 mL/min. The ultraviolet detective wavelength was set at 254 nm; The column temperature was room temperature. ResultsIn the range of 0.25-10.00 μg/mL (r=0.998 9), moxi-floxacin showed a good linear relation in HPLC. The recoveries of moxi-floxacin at three concentrations (0.5, 5.0, and 10.0 μg/mL) were 97.95%, 100.64%, and 102.84%, respectively, with intra-day relative standard deviation (RSD) at 3.49%, 1.45%, and 2.03%, respectively and intra-day RSD at 3.85%, 5.68%, 4.15%, respectively. ConclusionThe measuring method adopted in the experiment can accurately determinate the concentration of INH in the hydrothorax with high sensitivity and exceptional reproducibility.
ObjectiveTo establish a method for content determination of ferulic acid in Piwang massage lotion. MethodsHigh performance liquid chromatography was used. The analysis was carried on Diamonsil C18 (150 mm×4.6 mm, 5 μm, Dimma Science and Technology Co. Ltd.) column with mobile phase consisted of methanol-2% acetic acid (32︰68). The column temperature was 30℃. The detection wavelength was 320 nm. ResultsThe responses of ferulic acid liner in range of 4.55-91.00 μg/mL (R2=0.999 9). The average recovery of ferulic acid was 98.78% (relative standard deviation is 2.668%). ConclusionThe method is simple, rapid and good repeatability. It can be used for quality control of Piwang massage lotion
ObjectiveTo study the pharmacokinetics of lovastatin/niacin sustained-release tablets in healthy Chinese volunteers. MethodsEligible subjects were enrolled to receive a single dose of 20/500, 20/750 and 20/1 000 mg lovastatin/niacin sustained-release tablets and multiple dose of 20/1 000 mg lovastatin/niacin sustainedrelease tablets, one time per day, sustained for 5 days, respectively. Blood samples were obtained before dosing and up to 10, 20, 30, and 45 minutes, and 1 hour, 1.5, 2, 2.5, 3, 3.5, 4, 5, 7, 9, 12, and 15 hours after dosing. Niacin, niacinamide, nicotinuric acid and lovastatin were detected by high performance liquid chromatography-tandem mass spectrometry method. ResultsThe peak concertration and the area under the plasma concentration-time curve (0-t) of nicotinuric acid had linear dynamics characteristics with the dosage when the dose of niacin was between 500 and 1 000 mg. After multiple dosing, pharmacokinetics parameters of nicotinuric acid and lovastatin were close. No significant diTherence was found between male and female subjects. ConclusionLovastatin/niacin sustained-release tablets possess linear kinetics. Accumulation is not significant after multiple dosing. Gender doesn't affect the pharmacokinetics parameters.
ObjectiveTo establish an accurate and sensitive high performance liquid chromatography-mass spectrometric (HPLC/MS/MS) method for determination of vorinostat (SHA) and M2 metabolites in human serum, which was applicable for pharmacokinetic study of SHA. MethodsThe essay was conducted with an API 3000 HPLC-MS/MS system consisted of a Gemini C18 column (50 mm×3 mm, 3 μm), and the mobile phase consisted of methanol-acetonitrile-water-1 mol/L NH3-formic acid (25:15:60:0.1:0.05) at a flow rate of 0.23 mL/min. Acidulated serum samples were extracted by 3.5 mL diethyl ether which contains 3% isopropyl alcohol and was operated under the multiple reaction monitoring mode using the electrospray ionization technique. d5-SHA was used as the internal standard. ResultsThe retention time of SHA, M2 metabolite and internal standard were 4.1, 3.1 and 4.0 minutes, respectively. The linear range of SHA and M2 metabolite were in the range of 1-1 000 and 2-2 000 ng/mL, and the limit of quantity were 1.0 and 2.0 ng/mL; the method recovery were 93.0%-99.3% and 88.11%-104.12%, respectively. Matrixes effect of SHA and M2 metabolite were blow 9.0%. ConclusionThis method for the quantitative determination of SHA and M2 in human serum was proved to be simple, rapid, sensitive and accurate; it can be applied in the determination of SHA and M2 metabolite.
ObjectiveTo understand the nutritional status of vitamin D in some children aged 0-14 in Mianyang during the past 3 years and the changes of vitamin D nutritional status under home protection during the coronavirus disease 2019 (COVID-19) epidemic, so as to provide a theoretical basis for the monitoring and reasonable supplementation of vitamin D in children in this area after the epidemic.MethodsThe clinical data of children aged 0-14 who underwent physical examination in the Children’s Health Department of Mianyang Central Hospital from January to April 2018, from January to April 2019 and from January to April 2020 were analyzed retrospectively. High performance liquid chromatography tandem mass spectrometry was used to detect vitamin D, including vitamin D2, vitamin D3 and 25-hydroxyvitamin D [25(OH)D] in children’s serum. The differences in vitamin D components and 25(OH)D between different genders, different age groups, and different years were analyzed.ResultsA total of 12 348 children were included. The average vitamin D2 was (4.89±6.02) ng/mL, the average vitamin D3 was (22.91±9.29) ng/mL, the average 25(OH)D was (27.81±10.53) ng/mL, and 9 434 cases had sufficient 25(OH)D. The differences in vitamin D2, vitamin D3, 25(OH)D and 25(OH)D nutritional status in 2018, vitamin D2 and 25(OH)D in 2019, and vitamin D2 in 2020 between different genders were not statistically significant (P>0.05). There were statistically significant differences in vitamin D3 and 25(OH)D nutritional status in 2019, vitamin D3, 25(OH)D and 25(OH)D nutritional status in 2020 between different genders (P<0.05). From 2018 to 2020, vitamin D2 was the highest in infant group (P<0.05), while vitamin D3, 25(OH)D and 25(OH)D nutritional status were the highest in children group (P<0.05); vitamin D2 (χ2=143.106, P<0.001) showed an overall downward trend, vitamin D3 (F=400.178, P<0.001) and 25(OH)D (F=447.384, P<0.001) showed an overall upward trend; 25(OH)D nutritional status (χ2=103.566, P<0.001) was the highest in 2019.ConclusionsThe overall vitamin D nutritional status of children in Mianyang area is acceptable. Under the home protection, the average level of children’s serum 25(OH)D has little change, while the nutritional status of 25(OH)D has decreased significantly. After the outbreak of COVID-19, more attention should be paid to the monitoring and supplementation of vitamin D in school-age female children.