The metabolic profile of pseudolaric acid B (PB) was investigated by using in vivo and in vitro tests. Pseudolaric acid C2 (PC2) was identified as the specific metabolite of PB in plasma, urine, bile and feces using HPLC and HPLC-ESI/MS(n) after both oral and intravenous administration to rats, and almost no prototype was detected in all kinds of samples. The metabolic behaviors of PB orally administered in rats treated with antibiotics to eliminate intestinal microflora were identical with those in untreated rats, demonstrating that the metabolism of PB is independent of intestinal microflora. PB was stable in 48 h respective incubation with artificial gastric juice and artificial intestinal juice, suggesting that neither pepsin nor trypsin is in charge of metabolism of PB, and also demonstrating that PB is stable in both pH environments of gastric tract and intestinal tract. In vitro research on metabolism of PB in rat liver microsomes incubation revealed that little PB was metabolized and that the proposed metabolites were the demethoxy and demethoxydecarboxy products of the prototype. The amount of metabolites was extremely low compared with the prototype, indicating that liver microsomes are not responsible for the metabolism of PB either. PB was gradually metabolized into PC2 during 1 h in whole blood incubation in vitro, and the metabolic process showed dynamically dependent manner with incubation time. Once absorbed into blood, PB was quickly metabolized into PC2, accordingly, little prototype was detected in all kinds of samples. The metabolism was attributed to the rapid hydrolysis of C-19 ester bond by plasma esterase. These results clarified the metabolic pathway of PB for the first time, which was of great significance to identify the in vivo active form and interpret acting mechanism of the active compounds of P. kaempferi.

The preliminary metabolic profile of total diterpene acid (TDA) isolated from Pseudolarix kaempferi was investigated by using in vivo and in vitro tests. Pseudolaric acid C2 (PC2) was identified as the predominant metabolite in plasma, urine, bile and feces after both oral and intravenous administrations to rats using HPLC-UV and HPLC-ESI/MS(n), and demethoxydeacetoxypseudolaric acid B (DDPB), a metabolite proposed to be the glucoside of PC2 (PC2G), as well as pseudolaric acid C (PC), pseudolaric acid A (PA), pseudolaric acid A O-beta-D glucopyranoside (PAG), pseudolaric acid B O-beta-D glucopyranoside (PBG) and deacetylpseudolaric acid A (DPA) originated from TDA could also be detected. It was demonstrated by tests that the metabolism of TDA is independent of intestinal microflora, and neither of pepsin and trypsin is in charge of metabolism of TDA, TDA is also stable in both pH environments of gastric tract and intestinal tract. The metabolites of TDA in whole blood in vitro incubation were found to be PC2, DDPB and PC2G, which demonstrated that the metabolic reaction of TDA in vivo is mainly occurred in blood and contributed to be the hydrolysis of plasma esterase to ester bond, as well as the glucosylation reaction. These results clarified the metabolic pathway of TDA for the first time, which is of great significance to the in vivo active form and acting mechanism research of P. kaempferi.

Fragmentation behavior of diterpenoids was investigated by ESI/MSn and the qualitative analysis of diterpenoids in the bark of Pseudolarix kaempferi was performed using high-performance liquid chromatography/ multi-stage mass spectrometry (HPLC-ESI/MSn). The characteristic fragmentation behaviors of the diterpenoids are the cleavages of the lactone ring and C4-O bond. Furthermore, the eliminations of substituent groups at C-18, C-7 and C-8 can also be observed in the MS" (n = 3-4) spectra. For C-4 acetoxy subsititued diterpenoids, [M+Na-60]+ and [M-H-104] are the base peaks of MS2 spectra in the positive and negative ionization modes, respectively. For C-4 hydroxyl subsititued diterpenoids, [M+Na-44]+ and [M-H-62] are the base peaks of MS2 in the positive and negative ionization modes, respectively. For C-18 glucosylated or esterized diterpenoids, [M+Na-44]+ is the base peak of MS2 spectra in positive ionization mode. These fragmentation rules were successfully exploited in the identification of diterpenoids in methanol/water (6:4) extract of P. kaempferi by LC-MS in positive ionization mode. A total of 9 diterpenoids were identified or tentatively characterized, and one of them is reported here for the first time. The described method could be utilized for the sensitive and rapid qualitative analysis of P. kaempferi.

Objective To study the effect of deep inspiration breath-hold(DIBH)technique on the heart dose in whole breast irradiation(WBI)for left breast cancer after breast-conserving surgery, and to investigate the anatomical factors for heart dose. Methods Fifteen patients with left breast cancer who received WBI after breast-conserving surgery and met breathing control requirements were prospectively enrolled as subjects. Simulated CT scans were performed during free breathing(FB)and DIBH. The WBI plans were optimized based on DIBH images.The position,volume,and radiation doses to the heart and lung were compared between the status of FB and DIBH. Correlation of heart dose with various anatomical factors was analyzed in FB status. Between-group comparison of categorical data was made by nonparametric Wilcoxon rank test.A two-variable correlation analysis was made by the Pearson method.Results There was no significant difference in heart volume between the status of FB and DIBH(P=0.773).The volume of both lungs was significantly larger in DIBH status than in FB status(P=0.001). The mean and maximum doses and V5-V40for the heart,left anterior descending coronary artery,left ventricle,right ventricle,and left lung were significantly lower in DIBH status than in FB status(all P<0.05). The greater DIBH increased the lung volume,the greater the mean heart dose decreased. In FB status,the left breast volume,heart-to-lung volume ratio,distance between the inferior margins of breast and heart,and maximum heart margin distance showed a linear correlation with heart dose. Particularly, the heart-to-lung volume ratio and maximum heart margin distance were independently correlated with heart dose. Conclusions DIBH technique in WBI for left breast cancer after breast-conserving surgery significantly reduces heart and lung doses compared with FB. Changes in lung volume are the basis for improving the relative anatomical location of the heart. The heart-to-lung volume ratio and maximum heart margin distance may provide a reference for DIBH technique.

Objective:To evaluate the feasibility and efficacy of 68Ga-PSMA PET/CT-guided targeted prostate biopsy for the diagnosis of clinically significant prostate cancer(csPCa). Methods:This retrospective analysis allocated 89 patients with elevated PSA levels between 4.0-20.0 ng/ml to PET group(n=48) or TRUS group(n=41) between September 2017 and June 2019. Patients with PSMA-avid lesions (SUV max≥8.0) underwent PET-TB via a single-puncture percutaneous transgluteal approach (n=19), while patients with negative PSMA-PET underwent systematic TRUS-GB (n=29). Patients in the TRUS group who did not get 68Ga-PSMA PET/CT examination underwent TRUS-GB directly (n=41). The mean age, prostate volume, PSA value of PET group and TURS group were (71.2±9.1) years vs. (68.0±12.0) years, (62.9±29.1)ml vs. (65.4±38.9)ml , 8.8(6.6, 13.6) ng/ml vs. 9.8(7.1, 13.1)ng/ml, respectively (all P>0.05). The diagnostic efficacy and difference of PCa and csPCa between the two groups were compared. PET-TB adopts a new mode of percutaneous gluteus approach and carries out precise image fusion of PSMA-PET/CT and pelvic CT in the same machine and in the same position (prone position). Under the direct guidance of CT, the biopsy is performed with only one precise puncture. Results:PCa and csPCa were detected in 27/89(30.3%)and 20/89(22.5%)in all patients. PET group detected significantly more cases of PCa and csPCa than those of TRUS group [PCa: 41.7%(20/48) vs. 17.1%(7/41), χ2=6.328; csPCa: 33.3%(16/48) vs. 9.8%(4/41), χ2=7.055, P<0.01]. Of 19 patients with PSMA-PET positive, PET-TB detected 16 cases of PCa(84.2%) by a single needle puncture, and the proportions of cancer tissues were ≥80% in 2, 50%-79% in 8, and <50% in 6 cases. Among these, Gleason score was underestimated by biopsy histopathology in 2 patients. Of 3 patients with PET-TB negative, 1 case of low-risk PCa(Gleason 3+ 3) was detected by complementary TRUS-GB. The sensitivity, specificity, positive predictive value, negative predictive value, accuracy of 68Ga-PSMA PET/CT(SUV max≥8.0) for the diagnosis of csPCa were 73.9%(14/19), 93.1%(27/29), 87.5%(14/16), 81.3%(26/32)and 85.4%(41/48), respectively. For PET-TB, only one patient had slight symptoms of haematuria after the puncture, no cases of hematochezia, hemospermia, urinary retention or pelvic infection were observed. Conclusions:68Ga-PSMA PET/CT is a feasible novel puncture technique that may serve as a triage tool for prostate biopsy, and PET-TB may improve the detection rate of csPCa compared with TURS-GB, especially in patients with serum PSA 4.0-20.0 ng/ml.

OBJECTIVE To establish a method for the determination of plasma protein binding rate of imatinib and its metabolite（N-desmethyl imatinib ）and apply it to patients with gastrointestinal stromal tumor （GIST）.METHODS Using imatinib - d8 as the internal standard ，after being deproteinized methanol ，the sample was determined by equilibrium dialysis combined with liquid chromatography -tandem mass spectrometry . The free concentrations of imatinib and its metabolites in plasma of GIST patients were detected by the same method . RESULTS The protein binding rates of imatinib with albumin ，α1-acid glycoprotein and globulin at 120 ng/mL and 4 000 ng/mL were （92.5±1.0）% and（91.7±0.4）%，（56.6±2.0）% and（62.6±2.6）%，（56.3±3.1）% and （68.0±8.6）% ，respectively. The protein binding rates of N-desmethyl imatinib with albumin ，α1-acid glycoprotein and globulin at 60 ng/mL and 2 000 ng/mL were （90.6±3.5）% and（91.3±1.5）%，（54.1±5.1）% and（63.7±1.3）%，（56.2±7.6）% and（67.5±7.3）%，respectively. Compared with the low concentration group of imatinib （120 ng/mL）and its metabolite （60 ng/mL），the plasma protein binding rate of high concentration of imatinib （4 000 ng/mL）and its metabolite （2 000 ng/mL）with α1-acid glycoprotein and globulin was significantly increased （P＜ Δ基金项目 国家自然科学基金资助项目（No.81503160）；江苏省 0.05），but there was no signifi -cant difference with albumin 卫生健康发展研究中心 2021年度开放课题（No.JSHD2021004）；江苏 （P＞0.05）. In blank plasma ，the protein binding rates of imatinib（4 000 ng/mL）at high concentration and its metabolites（2 000 ng/mL）were significantly lower than those of low （120， 60 ng/mL） and medium （750， 375 ng/mL）concentration （P＜0.01）. Average protein binding rates of imatinib and its metabolite in plasma of GIST patients were （99.0±0.3）% and（99.2±0.3）%，respectively；the correlation coefficients between the concentrations of imatinib and its metabolites and the protein binding rates were －0.298 5 and －3.332 3，respectively（all P＜0.05）. CONCLUSIONS The method for determining the plasma protein binding rates of imatinib and its metabolites is successfully established . The plasma protein binding rates of imatinib and its metabolites in patients with GIST are negatively correlated with drug concentration .

OBJECTIVETo investigate the factors which may influence the imatinib plasma concentration in Chinese patients with gastrointestinal stromal tumor(GIST), and to illuminate the significance of monitoring imatinib plasma concentration in adjuvant therapy for patients with GIST.

METHODSA cross-sectional study with 60 GIST patients who accepted the imatinib therapy after surgery was conducted. They were respectively administrated in 10 domestic hospitals from December 2014 to April 2016, including The First Affiliated Hospital of Nanjing Medical University(n=28), The Affiliated Hospital of Nantong University(n=9), The Affiliated Hospital of Xuzhou Medical College(n=6), Nanjing Drum Tower Hospital(n=5), The Second Affiliated Hospital of Nanjing Medical University (n=2), Jingling Hospital (n=2), The Second People's Hospital of Lianyungang(n=2), Shandong Provincial Hospital(n=2), Jiangsu Province Tumor Hospital(n=2), and The First Affiliated Hospital of Zhejiang University(n=2). Some specific time points for collecting blood sample before and after taking imatinib were determined, then liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was used for monitoring imatinib plasma concentration in patients with GIST. Linear regression analysis was used for the correlation analysis of imatinib plasma concentration with dosage, clinicopathologic feature and side effect.

RESULTSPatients who could not tolerate 400 mg imatinib per day(n=3) received 300 mg per day. There was no significant difference in imatinib plasma concentration between patients with 300 mg and those with 400 mg imatinib(n=53)(P=0.527). However, the imatinib plasma concentration in patients with 600 mg imatinib per day (n=4) was significantly higher as compared to those with 400 mg(P=0.000). Linear regression analysis indicated a negative correlation between the imatinib plasma concentration in patients with 400mg imatinib per day for 90 days continuously and body surface area(R=0.074, P=0.035), but no significant correlations of with age, creatinine clearance and serum albumin concentration were observed (all P>0.05). The differences in imatinib plasma concentration were not statistically significant between patients of different gender and those taking proton-pump inhibitor (PPI) or not (both P>0.05). Difference in imatinib plasma concentration between patients with different surgery was significant (P=0.026). Compared to patients who underwent wedge resection, enterectomy and other surgeries, the imatinib plasma concentration of patients with subtotal gastrectomy or total gastrectomy decreased significantly (all P<0.05). After 90 days of taking imatinib continuously, linear regression analysis revealed a negative correlation between imatinib plasma concentration in patients with 400 mg imatinib per day and white blood cell count (R=0.103, P=0.013), and a positive correlation with serum alanine aminotransferase (ALT) concentration (R=0.076, P=0.033).

CONCLUSIONSThe imatinib plasma concentration in patients with larger body surface area, subtotal gastrectomy or total gastrectomy may be lower. For these patients, dosage of imatinib should be considered to increase in order to achieve effective plasma concentration. Excessive imatinib plasma concentration can result in some side effects, such as decrease of white blood cells and liver damage. Therefore, it is significant for receiving optimal clinical therapeutic efficacy to monitor imatinib plasma concentration, adjust imatinib dosage timely and keep imatinib plasma concentration in effective and safe range.

Adult ; Antineoplastic Agents ; administration & dosage ; pharmacokinetics ; Benzamides ; Combined Modality Therapy ; Cross-Sectional Studies ; Female ; Gastrectomy ; Gastrointestinal Stromal Tumors ; drug therapy ; surgery ; Humans ; Imatinib Mesylate ; administration & dosage ; pharmacokinetics ; Male ; Middle Aged ; Piperazines ; Pyrimidines ; Tandem Mass Spectrometry