Objective To develop an ultra-high performance liquid chromatography-mass spectrometry method(UPLC-MS/MS)for the determination of nirmatrelvir concentration in mouse plasma.Methods The ACQUITY UPLC system was used in tandem with an API 4000 triple quadrupole mass spectrometer.The analytical column was Waters BEH C18(2.1 mm×5.0 mm,1.7 μm)column,and the mobile phases consisted of water(containing 0.1％formic acid)and methanol(containing 0.1％formic acid)under gradient elution at the flow rate of 0.4 mL·min-1.The column temperature was set at 40 ℃,and the injection volume was 5 μL.Electrospray ionization was used as ion source,and positive multiple reaction monitoring mode was adopted to quantitatively analyze the ionization pairs m/z 500.3→110.3(nirmatrelvir)and m/z 237.3→193.3(carbamazepine).Carbamazepine was employed as an internal standard.Results The linear range of nirmatrelvir was from 10 ng·mL-1 to 2 560 ng·mL-1.For the quality control nirmatrelvir samples,the accuracies of intra-and inter-batch were less than±15％,and the precisions of intra-and inter-batch were lower than 15％.Nirmatrelvir in plasma was stable at room temperature for 24 h and remained stable after three freeze-thaw cycles.The extracted nirmatrelvir solution could be stored at 4℃ for 3 d without any visible change.Conclusion The method was characterized by good specificity,high sensitivity,and appropriate linear range.The methodological validation was in accordance with the 2020 edition of the Chinese Pharmacopoeia and could be applied to the quantitative detection of nirmatrelvir in plasma.

Objective:To investigate the molecular mechanism of the 5-methylcytosine(m5C)reader Y-box binding protein 1(YBX1)in participating in the development and progression of colorectal cancer(CRC)by regulating the stability of the ferroptosis inhibitor membrane-spanning 4-domains subfamily A 15(MS4A15).Methods:Bioinformatics databases were used to investigate the mRNA and protein expression levels of YBX1 in CRC.RT-qPCR was used to measure the expression level of YBX1 in CRC cells.LC-MS was used to measure the level of m5C modification in CRC cells and nor-mal colorectal mucosal cells.CCK-8 assay was used to observe the effect of YBX1 on the proliferation of CRC cells,Transwell assay was used to observe its effect on the migration ability of CRC cells,and flow cytometry was sued to observe its effect on the apoptosis of CRC cells.Bioinformatics methods were used to identify the ferrop-tosis inhibitors that can interact with YBX1 and potential m5C modification sites.GEPIA2 was used to analyze the association between the expression of YBX1 and MS4A15.The expression of YBX1 was inhibited,and then the mRNA expression level and m5C modifica-tion level of MS4A15 were analyzed.The catRAPID database was used to find the binding sites between YBX1 protein and MS4A15 mRNA.CRC cells were treated with actinomycin D after inhibition of YBX1 expression,and RT-qPCR was used to measure the stabil-ity of MS4A15 mRNA.The expression of MS4A15 was inhibited,and then the proliferative activity,migration ability,and apoptosis rate of cells were measured,as well as the expression levels of the key indicators for ferroptosis,including MDA,ROS,and Fe2+.Results:High mRNA and protein expression levels of YBX1 were observed in CRC,and YBX1 was highly expressed in CRC cells.The m5C modification level of CRC cells was significantly higher than that of normal colorectal mucosal cells.YBX1 could promote the prolifera-tion and migration of CRC cells and inhibit the apoptosis of CRC cells.The bioinformatics analysis showed that YBX1 was positively correlated with the expression level of the ferroptosis inhibitor MS4A15,and there were multiple m5C modification sites on MS4A15.Inhibition of YBX1 expression could reduce the mRNA expression level and m5C modification level of MS4A15 and the stability of MS4A15 mRNA.There were significant reductions in the proliferative activity and migration ability of CRC cells and a significant in-crease in the apoptosis rate of CRC cells after inhibition of MS4A15 expression,with significant increases in the content of MDA,ROS,and Fe2+.Conclusion:These results show that YBX1 promotes the development and progression of CRC by stabilizing MS4A15 via m5C modification,which provides a promising targeted therapeutic strategy for CRC patients.

Objective To develop an ultra-high performance liquid chromatography-mass spectrometry method(UPLC-MS/MS)for the determination of nirmatrelvir concentration in mouse plasma.Methods The ACQUITY UPLC system was used in tandem with an API 4000 triple quadrupole mass spectrometer.The analytical column was Waters BEH C18(2.1 mm×5.0 mm,1.7 μm)column,and the mobile phases consisted of water(containing 0.1％formic acid)and methanol(containing 0.1％formic acid)under gradient elution at the flow rate of 0.4 mL·min-1.The column temperature was set at 40 ℃,and the injection volume was 5 μL.Electrospray ionization was used as ion source,and positive multiple reaction monitoring mode was adopted to quantitatively analyze the ionization pairs m/z 500.3→110.3(nirmatrelvir)and m/z 237.3→193.3(carbamazepine).Carbamazepine was employed as an internal standard.Results The linear range of nirmatrelvir was from 10 ng·mL-1 to 2 560 ng·mL-1.For the quality control nirmatrelvir samples,the accuracies of intra-and inter-batch were less than±15％,and the precisions of intra-and inter-batch were lower than 15％.Nirmatrelvir in plasma was stable at room temperature for 24 h and remained stable after three freeze-thaw cycles.The extracted nirmatrelvir solution could be stored at 4℃ for 3 d without any visible change.Conclusion The method was characterized by good specificity,high sensitivity,and appropriate linear range.The methodological validation was in accordance with the 2020 edition of the Chinese Pharmacopoeia and could be applied to the quantitative detection of nirmatrelvir in plasma.

Purpose: This study aims to evaluate the efficacy and safety of a new combination treatment of vinorelbine and pyrotinib in human epidermal growth factor receptor 2 (HER2)–positive metastatic breast cancer (MBC) and provide higher level evidence for clinical practice. Materials and Methods: This was a prospective, single-arm, phase 2 trial conducted at three institutions in China. Patients with HER2-positive MBC, who had previously been treated with trastuzumab plus a taxane or trastuzumab plus pertuzumab combined with a chemotherapeutic agent, were enrolled between March 2020 and December 2021. All patients received pyrotinib 400 mg orally once daily plus vinorelbine 25 mg/m2 intravenously or 60-80 mg/m2 orally on day 1 and day 8 of 21-day cycle. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included the objective response rate (ORR), disease control rate (DCR), overall survival, and safety. Results: A total of 39 patients were enrolled. All patients had been pretreated with trastuzumab and 23.1% (n=9) of them had accepted trastuzumab plus pertuzumab. The median follow-up time was 16.3 months (95% confidence interval [CI], 5.3 to 27.2), and the median PFS was 6.4 months (95% CI, 4.0 to 8.8). The ORR was 43.6% (95% CI, 27.8% to 60.4%) and the DCR was 84.6% (95% CI, 69.5% to 94.1%). The median PFS of patients with versus without prior pertuzumab treatment was 4.6 and 8.3 months (p=0.017). The most common grade 3/4 adverse events were diarrhea (28.2%), neutrophil count decreased (15.4%), white blood cell count decreased (7.7%), vomiting (5.1%), and anemia (2.6%). Conclusion Pyrotinib plus vinorelbine showed promising efficacy and tolerable toxicity as second-line treatment in patients with HER2-positive MBC.

Objective:To evaluate the cost effectiveness of primary prophylaxis (PP) with pegylated recombinant human granulocyte colony stimulating factor (PEG-rhG-CSF), PP with recombinant human granulocyte colony stimulating factor (rhG-CSF) and no prophylaxis in women with early-stage breast cancer in China.Methods:Two phase Markov models were constructed for a hypothetical cohort of patients aged 45 with stage Ⅱ breast cancer. The first phase modelled costs and outcomes of 4 cycles docetaxel combined with cyclophosphamide [TC×4, febrile neutropenia (FN) risk>20%] chemotherapy, which assumptions based on literature reviews, including FN rates [base-case (deterministic sensitivity analysis range), 0.29 (0.24-0.35)] and related events [FN case-fatality, 3.4 (2.7-4.1)]. Second phase modelled the long term survival which was link with the relative dose intensity (RDI) [mortality hazard ratio ( HR) of RDI < 85% vs ≥85%, 1.45 (1.00-2.32)]. Clinical effectiveness, therapeutic costs, and economic utilities were estimated from peer-reviewed publications and expert opinions in case of unavailability of published evidences. Results:Compared to rhG-CSF PP and no prophylaxis, the cost of PEG-rhG-CSF PP increased to 5 208.19 RMB and 5 222.73 RMB, respectively. The quality-adjusted life-years (QALYs) enhanced to 0.066 and 0.297, respectively. Accordingly, the incremental cost effectiveness ratios (ICERs) are 79 146.3 RMB and 17 558.77 RMB per QALY, which were both below the willingness to pay (WTP) threshold of three times GDP per capita (18, 000 RMB) recommended by the WHO. Sensitivity analysis suggested that the more clinically effective the primary prophylaxis with PEG-rhG-CSF is, the more cost-effective primary prophylaxis with PEG-rhG-CSF will be. And the lower the mortality HR of RDI<85% vs ≥85% is, the more cost-effective primary prophylaxis with PEG-rhG-CSF will be. Conclusion:Although the cost of PP PEG-rhG-CSF is higher, considering the additional benefits, the administrating of PP PEG-rhG-CSF is likely to be a cost-effective alternative to PP rhG-CSF and no prophylaxis in patients with early stage breast cancer whose FN risks are more than 20% in China.

Objective:To evaluate the cost effectiveness of primary prophylaxis (PP) with pegylated recombinant human granulocyte colony stimulating factor (PEG-rhG-CSF), PP with recombinant human granulocyte colony stimulating factor (rhG-CSF) and no prophylaxis in women with early-stage breast cancer in China.Methods:Two phase Markov models were constructed for a hypothetical cohort of patients aged 45 with stage Ⅱ breast cancer. The first phase modelled costs and outcomes of 4 cycles docetaxel combined with cyclophosphamide [TC×4, febrile neutropenia (FN) risk>20%] chemotherapy, which assumptions based on literature reviews, including FN rates [base-case (deterministic sensitivity analysis range), 0.29 (0.24-0.35)] and related events [FN case-fatality, 3.4 (2.7-4.1)]. Second phase modelled the long term survival which was link with the relative dose intensity (RDI) [mortality hazard ratio ( HR) of RDI < 85% vs ≥85%, 1.45 (1.00-2.32)]. Clinical effectiveness, therapeutic costs, and economic utilities were estimated from peer-reviewed publications and expert opinions in case of unavailability of published evidences. Results:Compared to rhG-CSF PP and no prophylaxis, the cost of PEG-rhG-CSF PP increased to 5 208.19 RMB and 5 222.73 RMB, respectively. The quality-adjusted life-years (QALYs) enhanced to 0.066 and 0.297, respectively. Accordingly, the incremental cost effectiveness ratios (ICERs) are 79 146.3 RMB and 17 558.77 RMB per QALY, which were both below the willingness to pay (WTP) threshold of three times GDP per capita (18, 000 RMB) recommended by the WHO. Sensitivity analysis suggested that the more clinically effective the primary prophylaxis with PEG-rhG-CSF is, the more cost-effective primary prophylaxis with PEG-rhG-CSF will be. And the lower the mortality HR of RDI<85% vs ≥85% is, the more cost-effective primary prophylaxis with PEG-rhG-CSF will be. Conclusion:Although the cost of PP PEG-rhG-CSF is higher, considering the additional benefits, the administrating of PP PEG-rhG-CSF is likely to be a cost-effective alternative to PP rhG-CSF and no prophylaxis in patients with early stage breast cancer whose FN risks are more than 20% in China.

Hormone therapy is a major treatment option for hormone-receptor-positive (HR+) breast cancer. Resistance to hormone therapy is the major reason for disease recurrence and progression. Recent studies have identified several resistance mechanisms that lead to the estrogen-independent growth of HR+breast cancer and were exploited to develop novel target drugs, including cyclin-de-pendent kinases 4 and 6 (CDK4/6) inhibitor, mammalian target of rapamycin (mTOR) inhibitor, epidermal growth factor receptor family inhibitor, vascular endothelial growth factor inhibitor, histone deacetylase inhibitor, fibroblast growth factor receptor inhibitor, insulin-like growth factor receptor inhibitor, and checkpoint inhibitor. These inhibitors are being developed to block resistance pathways and improve the efficacy of hormonal therapy. Among these drugs, the mTOR inhibitor everolimus and the CDK4/6 inhibitor palbociclib are currently approved in the United States to treat metastatic HR+breast cancer. In this study, we summarize the frontier advances in the combination of hormone and target therapies.

Objective To explore the cause,treatment and prognosis of delayed massive haemorrhage (DMH) after pancreatic resection.Method Clinical data of 1554 patients undergoing pancreatectomy in our hospital from Aug 2003 to Aug 2013 were retrospectively analyzed.Results 16 patients suffered from DMH,including 13 patients who had undergone pancreaticoduodenectomy,and 3 patients who had had resection of pancreatic body and tail.Gastrointestinal haemorrhage occurred in 6 patients,intra-abdominal haemorrhage occurred in 10 patients,respectively.Reoperations were performed in 11 patients,transcatheter arterial embolization (TAE) undertaken in 2 patients,and endoscopic treatment in 3 patients.10 patients recovered after treatment,6 patients (6/16) died.Conclusions The mortality of DMH after pancreatic surgery is high.Postoperative pancreatic leak and gastrointestinal stress ulcer are the most possible risk factors,intra-abdominal arterial haemorrhage is the main cause of death.

Objective To identify risk factors for anastomotic leakage,and study the influence of high ligation of the inferior mesenteric artery on anastomotic leakage after rectal cancer resection.Methods The chi-test and the student t test were used for statistics.Clinical data were analyzed for 291 patients who underwent rectal cancer resection between August 2008 and November 2011.Results Anastomotic leakage occurred in 27 (9.3％) patients.Anastomotic leakage significantly increased in patients with tumours located within 10 cm from the anal verge,in male patients,and intraoperative blood loss.The use of high ligation of inferior mesenteric artery,which was associated with lower tumor location and surgical modality,was not a risk factor for anastomotic leakage,though it was associated with tumor stage and postoperative urinary retention.Conclusions Anastomotic leakage after rectal cancer resection is related to the tumor level,male gender,and perioperative bleeding,use of a high tie was not associated with an increased rate of symptomatic anastomotic leakage.

Objective To measure 5Fu concentration after intraoperative regional arterial perfusion chemotherapy in gastric antrum cancer patients.Method In this study,32 gastric antrum cancer patients intraoperatively received through right gastroepiploic artery intraarterial perfusion of 5-Fu (1000 mg/m2),and drug conentrations were measured in portal venous blood,peripheral venous blood,peritoneal fluid and in removed cancer tissues 2,5,10,20,30,60 minutes after infusion started by high performance liquid chromatography method.Result 5-Fu in portal vein blood and peritoneal fluid reached peak concentration after 2 minutes at (48.8 ±6.8) μg1/ml and (75.3 ±30.7) μg/ml,respectively.The drug concentration in portal venous blood was (19.2 ± 2.0) μg/ml at 30 minutes and that in peritoneal fluid was (17.3 ±7.4) μg/ml at 60 minutes,both were higher than that of the effective experimental tumor suppressing concentration (15 μg/ml).Peripheral venous blood concentration reached peak concentration of (5.4 ± 2.0) μg/ml at 5 minute.The drug concentration in removed cancer tissues was (80.5 ± 20.1) μg,/ml.Conclusions Regional intraarterial perfusion chemotherapeutics in gastric antrum cancer patients during operation immediately makes the concentration of chemotherapy rise in the portal vein blood and peritoneal fluid and in cancer tissues to a much higher level than that in peripheral blood.This helps kill cancer cells that fell out during the surgery.