Severe hypertriglyceridemia is a well-known cause of pancreatitis. Usually, there is a moderate increase in plasma triglyceride level during pregnancy. Additionally, certain pre-existing genetic traits may render a pregnant woman susceptible to development of severe hypertriglyceridemia and pancreatitis, especially in the third trimester. To elucidate the underlying mechanism of gestational hypertriglyceridemic pancreatitis, we undertook DNA mutation analysis of the lipoprotein lipase (LPL), apolipoprotein C2 (APOC2), apolipoprotein A5 (APOA5), lipase maturation factor 1 (LMF1), and glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1) genes in five unrelated pregnant Chinese women with severe hypertriglyceridemia and pancreatitis. DNA sequencing showed that three out of five patients had the same homozygous variation, p.G185C, in APOA5 gene. One patient had a compound heterozygous mutation, p.A98T and p.L279V, in LPL gene. Another patient had a compound heterozygous mutation, p.A98T & p.C14F in LPL and GPIHBP1 gene, respectively. No mutations were seen in APOC2 or LMF1 genes. All patients were diagnosed with partial LPL deficiency in non-pregnant state. As revealed in our study, genetic variants appear to play an important role in the development of severe gestational hypertriglyceridemia, and, p.G185C mutation in APOA5 gene appears to be the most common variant implicated in the Chinese population. Antenatal screening for mutations in susceptible women, combined with subsequent interventions may be invaluable in the prevention of potentially life threatening gestational hypertriglyceridemia-induced pancreatitis.
The purpose of the experiment was mainly to establish and verify a precise and straightforward ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) approach for simultaneously analyzing the concentration levels of amiodarone, dronedarone, and their metabolites (desethylamiodarone and desbutyldronedarone) in the plasma of Sprague-Dawley (SD) rats and to investigate the pharmacokinetics of all analytes in SD rats. After rapid protein precipitation by using acetonitrile, we accomplished the chromatographic separation of amiodarone, desethylamiodarone, dronedarone, desbutyldronedarone and ivabradine (internal standard, IS) by using Acquity BEH C18 column and detected through a mass spectrometer with Xevo TQ-S triple quadrupole tandem, choosing the positive ion mode. The approach showed wonderful linearity, and the range of calibration curve for amiodarone was 1–200 ng/mL, desethylamiodarone was 0.1–20 ng/mL, dronedarone was 0.5–100 ng/mL, and desbutyldronedarone was 0.25–50 ng/mL, respectively. For lower limit of quantification (LLOQ), the current method of UPLC-MS/MS can achieve values of 1.0 ng/mL for amiodarone, 0.1 ng/mL for desethylamiodarone, 0.5 ng/mL for dronedarone, and 0.25 ng/mL for desbutyldronedarone, respectively. The accuracy of intra-day and inter-day of all analytes was between −14.8% to 10.9%, while the precision was ≤ 13.3%. For each substance, the recovery rate was > 82.1%, besides, obvious matrix effect was not found. In all conditions, the stability of all analytes was comfirmed to the plasma sample quantification. In addition, the method of UPLC-MS/MS we developed could also be applied to measure the pharmacokinetic characteristics including amiodarone, desethylamiodarone, dronedarone, and desbutyldronedarone in the plasma of SD rats.
Abstract Cytochrome P450 3A4 ( CYP 3A4) is quantitatively the most important P450 enzyme in adults. It is suggested that CYP 3A4 genetic polymorphisms may influence the rate of the metabolism and elimination of CYP 3A4 substrates in human beings. Ibrutinib is an anticancer drug and primarily metabolized by CYP 3A4. The aim of this study was to systematically investigate the effects of 22 CYP 3A4 protein variants on the metabolism of ibrutinib in vitro . When compared with wild‐type CYP 3A4.1, two variants ( CYP 3A4.17 and CYP 3A4.24) had no detectable enzyme activity; five variants ( CYP 3A4.10, .11, .18, .23 and .33) exhibited no significant differences; another five variants ( CYP 3A4.3, .4, .9, .19 and .34) showed increased intrinsic clearance values, while the remaining nine variants ( CYP 3A4.2, .5, .14, .15, .16, .28, .29, .31 and .32) displayed decreased enzymatic activities in different degrees. As the first study of 22 CYP 3A4 protein variants in ibrutinib metabolism, these comprehensive data may help in the clinical assessment of the metabolism and elimination of ibrutinib and also offer a reference to the personalized treatment of ibrutinib in clinic.
A new, simple, and sensitive ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for quantification of fruquintinib was established to assess the pharmacokinetics of fruquintinib in the rat. The internal standard working solution was added to the plasma sample for extraction before analysis. The Acquity UPLC BEH C18 chromatography column (2.1 mm ×50 mm, 1.7 μm) was used to separated analytes under gradient elution using acetonitrile and 0.1% formic acid as the mobile phase. Positive multiple reaction monitoring modes were chosen to detect fruquintinib and diazepam (IS). The precursor-to-product ion transitions were 394.2 → 363.2 for fruquintinib and m/z 285 → 154 for IS. The current method was linear over the concentration range of 1.0-1000 ng/mL for fruquintinib with a correlation coefficient of 0.9992 or better. The matrix effect of fruquintinib and IS was acceptable under the current method. The intra- and interday precision (RSD%) and accuracy (RE%) were within 11.9% and ±13.7%, respectively. The recovery, stability, and sensitivity were validated according to the United States Food and Drug Administration (FDA) regulations for bioanalytical method validation. The analytical method had been validated and applied to a pharmacokinetic study of fruquintinib in rat.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)