Acta Pharmaceutica Sinica,Vol 53,No. 02
In this study, we developed a rapid and sensitive ultra high-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method to detect a sulfide bond doxorubicin conjugation prodrug (DOX-S-DOX) in human breast cancer tumor cells (MCF-7). The samples were prepared by acetonitrile precipitation using daunorubicin as internal standard (IS). A reversed phase C18 analytical column (Agilent Eclipse plus C18 RRHD 1.8 μm, 2.1 mm × 50 mm) was utilized to separate the samples under gradient elution conditions. Mobile phase was a mixture of 0.1% formic acid in water and methanol at a flow rate of 0.4 mL·min −1. The analysis was conducted on the mass spectrometer using an electrospray interface (ESI) in the positive ionization model. The calibration range was 20.0–400 ng·mL −1 with the correlation coefficients ( r2) ≥ 0.99. The inter- and intra-assay precision (relative standard deviation, RSD%) of quality control samples was within 3.77%–8.35% and relative error (RE%) for accuracy was between −2.04% and 2.62%. Recovery (97.67%–104.2%) and matrix effect (104.8%-113.9%) were consistent, precise, and reproducible at different quality control levels in accordance with FDA guidance. The assay was successfully used in the cellular pharmacokinetics study of DOX-S-DOX, which may provide a clue to explore analytical methods of other prodrug forms of DOX.
Nursing care of 14 patients with idiopathic pulmonary hypertension combined with left heart failure after lung transplantation
Chinese Journal of Nursing,Vol 52,No. 11
This paper summarized nursing experience of 14 patients with idiopathic pulmonary hypertension (IPAH) combined with left heart failure after lung transplantation. The key points of nursing included dynamic evaluation and maintenance of cardiac function, close monitoring and control, management of extracorporeal membrane oxygenation, mechanical ventilation and sequential noninvasive ventilation, early ambulation and rehabilitation. All 14 patients recovered and were discharged successfully.
Effect of different umbilical cord ligation methods on anemia and jaundice in preterm infants with a gestational age less than 32 weeks
Chinese Journal of Nursing,Vol 53,No. 02
Objective To investigate the effect of different umbilical cord ligation methods on anemia and jaundice in preterm infants with a gestational age less than 32 weeks. Methods A total of 135 preterm infants with a gestational age less than 32 weeks were recruited and randomly divided into the umbilical cord milking group, the delayed cord clamping group and the immediate cord clamping group, with 45 cases in each group. Comparisons among the three groups were performed on hemoglobin and hematocrit 1 h and 1 week after birth, and bilirubin peak, total time of phototherapy, the anemia rate, pathologic jaundice as well as polycythemia before discharge. Results Finally, 40 cases in the umbilical cord milking group, 42 cases in the delayed cord clamping group and 38 cases in the immediate cord clamping group were recruited. Compared with the immediate cord clamping group, Hb (g/L) and hematocrit (%) levels were significantly high in the umbilical cord milking group and the delayed cord clamping group ( P < 0.05) and the anemia rate was significantly low in umbilical cord milking group and the delayed cord clamping group ( P < 0.05). However, there was no statistical difference in Hb (g/L) and hematocrit (%) levels as well as anemia rate between the umbilical cord milking group and the delayed cord clamping group ( P > 0.05). There was no significant difference among the three groups in bilirubin peak, total time of phototherapy and the incidence of pathologic jaundice as well as polycythemia. Conclusion Umbilical cord milking and delayed cord clamping can both reduce the anemia rate, but can not increase the risk of pathological jaundice. Umbilical cord milking can be the preferred method for preterm infants with a gestational age less than 32 weeks and asphyxia.
Determination of Residual Pichia Pastoris DNA in Recombinant Human Albumin Products by Magnetic Beads-Based Extraction Combined with Quantitative PCR Method
Chinese Pharmaceutical Journal,Vol 53,No. 10
OBJECTIVE To develop and verify a magnetic beads-based extraction combined with quantitative PCR (q-PCR) method for determination of residual host cell DNA in recombinant human albumin products expressed in Pichia pastoris. METHODS The residual Pichia pastoris host cell DNA in samples were extracted by magnetic beads-based extraction method and then determined by Taqman probe-based q-PCR. The residual DNA content was calculated according to the standard curve. The developed method was verified for accuracy and precision with different derivation albumin matrixes and concentrations, and the residual DNA of 3 batches of recombinant human albumin products expressed in Pichia pastoris were detected. RESULTS The minimum detection limit of Pichia pastoris residual DNA by the developed method was 3 fg·μL −1, the linear range was 3 fg·μL −1–300 pg·μL −1, and the correlation coefficient ( r2) was 0.998 3. The recovery rates of spiked samples in rHA matrix were 93.58% (RSD 19.6%, n = 4) at 100 fg·μL −1 and 215.56% (RSD 42.9%, n = 4) at 10 fg·μL −1, respectively. The recovery rates of spiked samples in HSA matrix were 67.09% (RSD 6.9%, n = 3) at 100 fg·μL −1 and 113.40% (RSD 11.1%, n = 3) at 10 fg·μL −1, respectively. The residual Pichia pastoris DNA contents in 3 batches of recombinant human albumin products expressed in Pichia pastoris determined by the developed method were 5.98, 4.16, 4.49 fg·μL −1 ( n = 7) respectively and not more than 1 ng per 10 g protein. CONCLUSION Magnetic beads extraction method combined with fluorescence quantitative PCR method solves the technical problem of quantitative determination of trace DNA in recombinant human albumin products with ultra-high concentration protein. The method is accurate and reproducible, and can be used for quantitative determination of DNA residue in recombinant human albumin expressed by Pichia pastoris.
Chinese Pharmaceutical Journal,Vol 53,No. 11
OBJECTIVE To establish an HPLC-MS/MS method to identify the unknown impurities in polymyxin B sulfate. METHODS The analysis was performed on Agilent 1260-6550 Q/TOF-MS with a Diamonsil Plus C 18 column (4.6 mm × 250 mm, 5 μm). Mobile phase A was 0.01 mol·L −1 trifluoroacetic acid-acetonitrile (95:5), and mobile phase B was acetonitrile containing 0.1% formic acid. Mobile phase A and B were set at the volume ratio of 79:21 at a flow rate of 1 mL·min −1 under isocratic elution. The detection wavelength was set at 254 nm. ESI source was used. Positive ion scanning was conducted in the range of m/ z 50–1 700 for MS and MS/MS. The unknown components were identified by comparing the MS and MS/MS with the known reference standards like polymyxin B 1 and B 2. The photochemical Paterño-Büchi reaction was performed using a low-pressure mercury lamp as the light source at emission wavelength of 254 nm with acetone/water (50/50, V/ V) as the reaction solvent. RESULTS The structures of seven unknown related substances in polymyxin B sulfate were identified. The most abundant impurity was identified to be vinyl polymyxin B 1, for which the double bond was at the end of the fatty acyl residue. CONCLUSION Vinyl polymyxin B 1 is reported for the first time. The method provides a good idea for the identification of related substances in drugs.