Cancer Pain Syndromes.

Pain from cancer can present in a multitude of ways. In this chapter, we will identify the types of cancer pain and their etiologies. Following this, we will explore how cancer pain can present as somatic pain, visceral pain, and neuropathic pain. We will explore the aspects of the history and physical examination that point to specific diagnoses of pain and how to appropriately treat each diagnosis appropriately. Finally, we will touch upon a phenomenon known as opioid neurotoxicity.

Implications of Prolonged Time to Pancreaticoduodenectomy After Neoadjuvant Chemoradiation.

BACKGROUND: For patients with pancreatic adenocarcinoma (PA), the optimal time interval between neoadjuvant chemoradiation (CR) to surgical resection has not been well established. METHODS: The National Cancer Database from 2006 to 2014 was queried for patients ≥18 y old diagnosed with PA who received neoadjuvant CR. Survival and short-term outcomes were compared between patients who had pancreaticoduodenectomy ≤12 wk and >12 wk after completion of CR. RESULTS: 1610 patients met selection criteria. Average radiation to surgery (RS) interval was 58.2 ± 39.5 d. 1419 patients had RS interval ≤12 wk (mean 47.4 d) and 191 had RS interval >12 wk (mean 138.8 d). Demographics, CA 19-9 levels, types of chemotherapy and radiation dosage were similar between the two groups. There were more patients with clinical stage III cancers in the >12 wk group than in the ≤12 wk group (33.5% versus 14%). Short-term outcomes were similar between the two groups. However, a long-term survival benefit was observed in the >12 wk group (median 25.8 versus 30.2 mo P = 0.049). An interval >12 wk was associated with significantly prolonged survival on multivariate analysis (HR: 0.80, 95% CI: 0.65-0.99; P = 0.042). Higher clinical stage and positive surgical margins were independently associated with worse survival. CONCLUSIONS: Surgical resection beyond 12 wk after CR for PA did not worsen short-term outcomes. Waiting may contribute to better patient selection, especially those with locally advanced tumors. In the absence of progressive disease, patients need to be continuously evaluated for surgical resection after CR.

Robotic Versus Laparoscopic Gastrectomy for Gastric Adenocarcinoma: Propensity-Matched Analysis.

Background. We compared the outcomes of laparoscopic-assisted (LA) and robotic-assisted (RA) gastrectomies performed for gastric adenocarcinoma in the National Cancer Database. Methods. The National Cancer Database was queried for patients 18 years old with stages I to III gastric adenocarcinoma who underwent LA or RA gastrectomy. Propensity matching was performed between the 2 groups with regard to clinical staging, adjuvant treatment, demographics, and the extent of surgery. Results. A cohort of 1893 (1262 = LA, 631 = RA) patients was identified in a 2:1 propensity matching. The groups were well matched. The rate of negative margin as well as 30- and 90-day mortality were similar between the 2 cohorts. Long-term survival was similar between the 2 groups (median survival 49.2 months in LA vs 56.2 months for RA, P = .405). However, the average number of lymph nodes (LNs) sampled was significantly higher in the RA group compared with the LA group (19.6 vs 17.4, P < .001). Similarly, the percentage of surgeries in which ≥15 LNs were sampled was also greater in the RA group compared with the LA group (63.9% vs 57.6%, P = .010). On multivariable analysis, having 15 LNs or more examined was associated with better survival (hazard ratio = 0.72, 95% confidence interval = 0.60-0.87, P < .001). Advanced age, nodal positivity, and advanced clinical stages were significantly associated with worse survival. Conclusions. RA gastrectomy may allow a greater harvest of LNs, and thus more accurate staging, without increasing short-term adverse outcomes compared with LA gastrectomy. Short-term and long-term outcomes in this well-matched cohort appear comparable for both approaches.

Racial disparities in breast cancer persist despite early detection: analysis of treatment of stage 1 breast cancer and effect of insurance status on disparities.

PURPOSE: Prior research demonstrates racial disparities in breast cancer treatment. Disparities are commonly attributed to more advanced stage at presentation or aggressive tumor biology. We seek to evaluate if racial disparities persist in the treatment of stage 1 breast cancer patients who by definition are not delayed in presentation. METHODS: We selected stage 1 breast cases in the National Cancer Data Base. Patients were divided into two cohorts based on race and included White and Black patients. We also performed a subgroup analysis of patients with private insurance for comparison to determine if private insurance diminished the racial disparities noted. We analyzed differences in time to treatments by race. RESULTS: Our analysis included 546,351 patients of which 494,784 (90.6%) were White non-Hispanic and 51,567 (9.4%) were Black non-Hispanic. Black women had significantly longer times to first treatment (35.5 days vs 28.1 days), surgery (36.6 days vs 28.8 days), chemotherapy (88.1 days vs 75.4 days), radiation (131.3 days vs 99.1 days), and endocrine therapy (152.1 days vs 126.5 days) than White women. When patients with private insurance were analyzed the difference in time to surgery decreased by 1.2 days but racial differences remained statistically significant. CONCLUSIONS: Despite selecting for early-stage breast cancer, racial disparities between White and Black women in time to all forms of breast cancer treatment persist. These disparities while likely not oncologically significant do suggest institutional barriers for obtaining care faced by women of color which may not be addressed with improving access to mammography alone.

Trends and Outcomes of Synchronous Resection of Colorectal Metastasis in the Modern Era-Analysis of Targeted Hepatic NSQIP Database.

BACKGROUND: Previous studies using the NSQIP database to study hepatectomies lacked hepatic specific variables and outcomes. We used the targeted NSQIP hepatectomy database to examine the nationwide trend and the safety profile of synchronous liver and colorectal resection compared with hepatectomy alone for colorectal liver metastasis. METHODS: The targeted NSQIP hepatectomy database from 2014 was used to study patients who underwent hepatectomy for diagnosis of adenocarcinoma of the colon and rectum. RESULTS: Of the 3064 hepatic resections in the database, 1138 cases were performed for colorectal metastasis. Of these, 1040 were liver-alone surgery and 98 were synchronous liver and colorectal resection. Most (58.7%) patients received neoadjuvant therapy. The rate of neoadjuvant therapy, intraoperative ablation, biliary reconstruction, and the use of minimally invasive technique were similar between the two groups. The overall 30-d mortality in this cohort was low (1.1%). While the mortality rate in the synchronous group was similar to liver-only group (3.1% versus 0.9%, P = 0.077). The rate of liver failure (3.3% versus 4.1%, P = 0.722) and biliary leak (5.3% versus 9.6%, P = 0.084) were similar between the two groups. However, the rate of major complications was higher on multivariable analyses (25.5% versus 12.1%, OR 2.5, 95% CI 1.5-4.1, P < 0.001) for the synchronous group. CONCLUSIONS: Hepatic resection for colorectal metastasis in the modern era has low short-term mortality. While synchronous resection was associated with a higher incidence of major complications, liver-specific complications did not increase with synchronous resection.

Resectable Distal Pancreas Cancer: Time to Reconsider the Role of Upfront Surgery.

BACKGROUND: Neoadjuvant chemotherapy (NAC) is increasingly utilized to optimize survival in proximal pancreatic adenocarcinoma. However, few studies have explored the impact of NAC in distal pancreas cancer. METHODS: Patients with resectable pancreatic adenocarcinoma of the body or tail treated with either upfront pancreatectomy or NAC followed by surgery were identified in the 2006-2014 National Cancer Database. Trends in utilization, predictors of use, and impact of NAC on overall survival were determined. RESULTS: Of 1485 patients, 176 (11.9%) received NAC. Use of NAC increased from 9.3% in 2006 to 16.9% in 2013 [odds ratio 1.14; 95% confidence interval (CI) 1.05-1.24; p = 0.001]. NAC patients were younger, had higher clinical stage, and preoperative CA 19-9 levels (all p < 0.05). After adjustment for patient-, tumor-, and treatment-related factors, increased clinical stage was the greatest independent predictor of neoadjuvant approach (p < 0.001). On multivariable analysis, survival benefit from NAC did not reach threshold of significance (95% CI 0.66-1.04; p = 0.10) for the entire cohort. However, NAC was associated with a significant survival advantage in clinical stage III with a 51% decreased yearly risk of death (adjusted hazard ratio 0.49; 95% CI 0.25-0.98; p = 0.04). A trend towards improved survival with NAC was observed among stage IIA (p = 0.09) and IIB (p = 0.07) patients. CONCLUSIONS: Neoadjuvant chemotherapy is associated with improved overall survival in Stage III distal pancreatic adenocarcinoma and shows promise in earlier stage disease. However, only a small percentage of patients receive NAC. Prospective evaluation of NAC in distal pancreatic adenocarcinoma is warranted based on these findings.

Intercalating Single-Atom Metal Centers into an Organic Monolayer with a Full-Sample Coverage.

Thiolate self-assembled monolayers (SAMs) have been widely used as a straightforward method to functionalize the surface of a common substrate with selective organic functional groups. Here we describe a process that further introduces isolated metal centers into an organic SAM using solutions of metallic porphyrin so that different organic groups and metal single-atoms can be simultaneously exposed on top of the surface. The entire process employs only common laboratory equipment and mild-temperature (<100 °C) incubation to create a full-sample (>cm2) SAM coverage. Each step in this process is closely monitored and discussed using nm-scale scanning tunneling microscopy (STM) images. This work can be straightforwardly adopted by research groups interested in such a diversely customizable surface but without access to a vacuum-based deposition technology. The porphyrin molecules are shown to intercalate among closely packed thiolate SAM domains, and STM characterization shows that the entire mixed monolayer is stable in an ambient condition. This process also does not involve any tip-assisted desorption or lithography procedure and can thus be applied toward substrates of other shapes beyond a flat surface.

Racial and Socioeconomic Treatment Disparities in Adolescents and Young Adults with Stage II-III Rectal Cancer.

INTRODUCTION: Stage II-III rectal cancer requires multidisciplinary cancer care, and adolescents and young adults (AYA, ages 15-39 years) often do not receive optimal cancer therapy. METHODS: Overall, 3295 AYAs with clinical stage II-III rectal cancer were identified in the National Cancer Database. Factors associated with the receipt of adjuvant and surgical therapies, as well as overall survival (OS), were examined. RESULTS: The majority of patients were non-Hispanic White (72.0 %), male (57.5 %), and without comorbidities (93.8 %). A greater proportion of Black and Hispanic patients did not receive radiation (24.5 and 27.1 %, respectively, vs. 16.5 % for non-Hispanic White patients), surgery (22.4 % and 21.6 vs. 12.3 %), or chemotherapy (21.5 % and 24.1 vs. 14.7 %) compared with non-Hispanic White patients (all p < 0.05). After controlling for competing factors, Black (odds ratio [OR] 0.7, 95 % confidence interval [CI] 0.5-0.9) and Hispanic patients (OR 0.6, 95 % CI 0.4-0.9) were less likely to receive neoadjuvant chemoradiation compared with non-Hispanic White patients. Females, the uninsured, and those treated at a community cancer center were also less likely to receive neoadjuvant therapy. Having government insurance (OR 0.22, 95 % CI 010-0.49) was a predictor for not receiving surgery. Although 5-year OS was lower (p < 0.05) in Black (59.8 %) and Hispanic patients (65.9 %) compared with non-Hispanic White patients (74.9 %), on multivariate analysis race did not impact mortality. Not having surgery (hazard ratio [HR] 7.1, 95 % CI 2.8-18.2) had the greatest influence on mortality, followed by poorly differentiated histology (HR 3.0, 95 % CI 1.3-6.5), nodal positivity (HR 2.6, 95 % CI 1.9-3.6), no chemotherapy (HR 1.9, 95 % CI 1.03-3.6), no insurance (HR 1.7, 95 % CI 1.1-2.7), and male sex (HR 1.5, 95 % CI 1.1-2.0). CONCLUSION: There are racial and socioeconomic disparities in the treatment of stage II-III rectal cancer in AYAs, many of which impact OS. Interventions that can address and mitigate these differences may lead to improvements in OS for some patients.

Outcomes of octogenarians undergoing gastrectomy performed for malignancy.

BACKGROUND: Studies on perioperative outcomes of octogenarians with gastric cancer are limited by small sample size. Our aim was to determine the outcomes of gastrectomy and the variation of treatments associated with advanced age (≥80 y). METHODS: The National Surgical Quality Improvement Program database was queried from 2005 to 2011. Patients who underwent gastrectomy for malignancy were identified using International Classification of Diseases, Ninth Revision and Current Procedural Terminology codes. RESULTS: Of 2591 cases, 487 patients were octogenarians (≥80) and 2104 were nonoctogenarians (<80). Overall, 4.9% of patients had disseminated cancer. Octogenarians had higher 30-d mortality (7.2% versus 2.5%, P < 0.01) and more major complications (31.4% versus 25.5%, P < 0.01), though fewer octogenarians underwent total gastrectomy (24.0% versus 43.2%, P < 0.01) and extended lymphadenectomy (10.1% versus 17.4%, P < 0.01) than the nonoctogenarian cohort. On multivariate analysis, age ≥80 y was associated with major complications (OR, 1.3; 95% CI, 1.03-1.6; P = 0.03) and increased mortality (OR, 3.0; 95% CI, 1.9-4.9; P < 0.01). CONCLUSIONS: Advanced age (≥80 y) was associated with worse outcomes in patients undergoing gastrectomy for malignancy. Therefore, careful staging is necessary to reduce unnecessary operations in this population. Furthermore, surgeons must place greater attention on optimizing the octogenarian population before surgery.

Asymmetric total synthesis of tetrahydroprotoberberine derivatives and evaluation of their binding affinities at dopamine receptors.

Cocaine addiction remains a serious challenge for clinical and medical research because there is no effective pharmacological treatment. l-THP, a natural product isolated from Corydalis yanhusuo W.T. Wang, is one of the most frequently used traditional herbs to treat drug addiction in China. Our laboratory first reported that its demethylated metabolites l-ICP, l-CD, and l-CP had high affinity at dopamine D1, D2, and D5 receptors. Here we report the chemical synthesis of these metabolites and other derivatives and their binding affinities at dopamine receptors. The synthesis of these bioactive metabolites will allow further in vivo study of their potential in treating cocaine addiction.

Pharmacokinetics, tissue distribution, and excretion studies of l-isocorypalmine using ultra high performance liquid chromatography with tandem mass spectrometry.

l-Isocorypalmine is a newly identified metabolite of l-tetrahydropalmatine with a unique dual pharmacological profile as a partial dopamine receptor 1 agonist and dopamine receptor 2 antagonist properties for treating cocaine use disorder. The purpose of this study was to explore the pharmacokinetic profiles, tissue distribution, and excretion of l-isocorypalmine in Sprague-Dawley rats. A sensitive and reliable ultra high performance liquid chromatography with tandem mass spectrometry method was developed and validated for determination of l-isocorypalmine in biological samples. The biological samples were extracted by liquid-liquid extraction and separated on a Bonshell ASB C18 column (2.1 × 100 mm, 2.7 µm, Agela) with gradient mobile phase at the flow rate of 0.2 mL/min. The detection was performed by positive electrospray ionization with multiple reaction monitoring mode. Satisfactory linearity, precision, accuracy, extraction recovery, and acceptable matrix effect were achieved. The quantitative method was successfully applied to the pharmacokinetics, tissue distribution, and excretion study of l-isocorypalmine. The results showed that l-isocorypalmine was rapidly distributed, and eliminated from rat plasma and manifested linear dynamics in a dose range of 7.5-15 mg/kg. In addition, the results would be helpful for further clinical reference of l-isocorypalmine as a potential candidate drug for the treatment of cocaine addiction.

Simultaneous determination of l-tetrahydropalmatine and its active metabolites in rat plasma by a sensitive ultra-high-performance liquid chromatography with tandem mass spectrometry method and its application in a pharmacokinetic study.

A sensitive and reliable ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for simultaneous determination of l-tetrahydropalmatine (l-THP) and its active metabolites l-isocorypalmine (l-ICP) and L-corydalmine (l-CD) in rat plasma. The analytes were extracted by liquid-liquid extraction and separated on a Bonshell ASB C18 column (2.1 × 100 mm; 2.7 µm; Agela) using acetonitrile-formic acid aqueous as mobile phase at a flow rate of 0.2 mL/min in gradient mode. The method was validated over the concentration range of 4.00-2500 ng/mL for l-THP, 0.400-250 ng/mL for l-ICP and 1.00-625 ng/mL for l-CD. Intra- and inter-day accuracy and precision were within the acceptable limits of <15% at all concentrations. Correlation coefficients (r) for the calibration curves were >0.99 for all analytes. The quantitative method was successfully applied for simultaneous determination of l-THP and its active metabolites in a pharmacokinetic study after oral administration with l-THP at a dose of 15 mg/kg to rats.

Development and validation of a high performance liquid chromatography quantification method of levo-tetrahydropalmatine and its metabolites in plasma and brain tissues: application to a pharmacokinetic study.

Levo-tetrahydropalmatine (l-THP) is an alkaloid isolated from Chinese medicinal herbs of the Corydalis and Stephania genera. It has been used in China for more than 40 years mainly as an analgesic with sedative/hypnotic effects. Despite its extensive use, its metabolism has not been quantitatively studied, nor there a sensitive reliable bioanalytical method for its quantification simultaneously with its metabolites. As such, the objective of this study was to develop and validate a sensitive and selective HPLC method for simultaneous quantification of l-THP and its desmethyl metabolites l-corydalmine (l-CD) and l-corypalmine (l-CP) in rat plasma and brain tissues. Rat plasma and brain samples were processed by liquid-liquid extraction using ethyl acetate. Chromatographic separation was achieved on a reversed-phase Symmetry® C18 column (4.6 × 150 mm, 5 µm) at 25°C. The mobile phase consisted of acetonitrile-methanol-10 mm ammonium phosphate (pH 3) (10:30:60, v/v) and was used at a flow rate of 0.8 mL/min. The column eluent was monitored at excitation and emission wavelengths of 230 and 315 nm, respectively. The calibration curves were linear over the concentration range of 1-10,000 ng/mL. The intra- and interday reproducibility studies demonstrated accuracy and precision within the acceptance criteria of bioanalytical guidelines. The validated HPLC method was successfully applied to analyze samples from a pharmacokinetic study of l-THP in rats. Taken together, the developed method can be applied for bioanalysis of l-THP and its metabolites in rodents and potentially can be transferred for bioanalysis of human samples.

Predictors and Survival Impact of False-Negative Sentinel Nodes in Melanoma.

BACKGROUND: The status of the sentinel lymph node in melanoma is an important prognostic factor. The clinical predictors and implications of false-negative (FN) biopsy remain debatable. METHODS: We compared patients with positive sentinel lymph node biopsy (SNB) [true positive (TP)] and negative SNB with and without regional recurrence [FN, true negative (TN)] from our prospective institutional database. RESULTS: Among 2986 patients (84 FN, 494 TP, and 2408 TN; median follow-up 93 months), the incidence of FN-SNB was 2.8%. While calculated FN rate was 14.5% [84 FN/(494 TP + 84 FN) × 100], when we accounted for local/in-transit recurrence (LITR) this rate was 8.5% [46 FN/(494 TP + 46 FN) × 100 %]. On multivariate analysis, male gender (OR 2.0, 95% CI 1.1-3.6, p = 0.018), head/neck primaries (OR 2.5, 95% CI 1.3-4.8, p < 0.006), and LITR (OR 3.5, 95% CI 2.1-5.8, p < 0.001) were associated with FN-SNB. Melanoma-specific survival (MSS) for the FN group was similar to the TP group at 5 years (68 vs. 73%, p = 0.539). However, MSS declined more for the FN group with a longer follow up and was significantly worse at 10 years (44 vs. 64%, p < 0.001). On multivariate analysis, FN-SNB was a significant predictor of worse MSS in melanomas <4 mm in Breslow thickness (HR 1.6; 95% CI 1.1-2.5, p = 0.021). CONCLUSIONS: Male gender, LITR, and head and neck tumors were associated with FN-SNB. FN-SNB was an independent predictor of worse MSS in melanomas <4 mm in thickness, but this survival difference did not become apparent until after 5 years of follow-up.

The identification of risk factors for venous thromboembolism in gastrointestinal oncologic surgery.

BACKGROUND: The aim of this study was to examine the incidence and factors associated with occurrence of venous thromboembolism (VTE) in patients undergoing major gastrointestinal (GI) surgery for malignancy. METHODS: The American College of Surgeon's National Surgical Quality Improvement Program, Participant User File database was queried from 2005 to 2012 to study major GI operations performed for cancer. Predictors of VTE and their relation to survival were studied. RESULTS: In 79,300 patients, the incidence of deep venous thrombosis was 1.7%, and pulmonary embolism was 0.9% during the 30-d postoperative period. The highest rate of VTE occurred after esophagectomy (5.9%) followed by pancreatectomy (3.2%), hepatectomy (3.2%), gastrectomy (2.5%), enterectomy (2.3%), colectomy, and proctectomy (2.0%). On multivariate analysis, disseminated cancer, age ≥ 80 y, body mass index > 35 kg/m(2), functional status, post operative sepsis, pulmonary dysfunction, and longer operative time were associated with occurrence of VTE. Occurrence of VTE was associated with mortality on multivariate analysis (odds ratio 2.4, 95% confidence interval 2.0-3.0, P < 0.001). CONCLUSIONS: Absolute incidence of VTE after major GI surgery is low but is associated with significant mortality and postoperative complications. Disseminated cancer, post operative sepsis, longer operative time, and increased body mass index >35 kg/m(2) further increased the risk of VTE in patients undergoing surgery for malignancy. Surveillance strategies should be implemented for those cancer patients who have multiple risk factors for VTE.

Patterns and outcomes of colorectal cancer in adolescents and young adults.

BACKGROUND: The incidence of colorectal cancer (CRC) in the adolescent and young adult (AYA) population (aged 15-39 y) is rising. MATERIALS AND METHODS: We used the Surveillance, Epidemiology, and End Results Database to study CRC in the AYA population. We studied clinical and socioeconomic factors associated with survival. RESULTS: Of the 11,071 cases of CRC, the most common site of the primary tumor was the rectum (25%), whereas 66.6% of the diseases were left sided. Most of the patients (72%) presented with regional or metastatic disease. However, the disease-specific survival (DSS) and the overall survival of the AYA population were comparable to those of the general population (DSS; 5- and 10-y: 64.8%, 57.3%; overall survival; 5- and 10-y: 61.5% and 52.4%). On multivariate analysis, disease stage at the time of the diagnosis was the strongest predictor of mortality. After controlling for disease stage, male gender, black race, and higher grade tumors were associated with worse survival. CONCLUSIONS: The AYA population presents with advanced distal CRC but have similar survival compared with the general population.

Ultra-high performance liquid chromatography with tandem mass spectrometry method for the simultaneous quantitation of five phthalides in rat plasma: Application to a comparative pharmacokinetic study of Huo Luo Xiao Ling Dan and herb-pair extract.

A fast, sensitive, and reliable ultra-high performance liquid chromatography with tandem mass spectrometry method has been developed and validated for the simultaneous quantitation and pharmacokinetic study of five phthalides (senkyunolide A, ligustilide, butylidenephthalide, 3-butylphthalide, and levistilide A) in rat plasma after oral administration of Huo Luo Xiao Ling Dan (HLXLD) or Angelica sinensis--Ligusticum chuanxiong herb pair (DG-CX) between normal and arthritis rats. After extraction from blood, the analytes and internal standard were subjected to ultra-high performance liquid chromatography with a Shim-pack XR-ODS column (75 × 3.0 mm(2) , 2.2 µm particles) and mobile phase was composed of methanol and water (containing 0.05% formic acid) under gradient elution conditions, with an electrospray ionization source in the positive ionization and multiple reaction monitoring mode. The lower limits of quantification were 0.192-0.800 ng/mL for all the analytes. Satisfactory linearity, precision, accuracy, mean extraction recovery, and acceptable matrix effect have been achieved. The validated method was successfully applied to a comparative pharmacokinetic study of five bioactive components in rat plasma after oral administration of HLXLD or DG-CX alone, respectively, between normal and arthritic rats. The results showed that there were unlike characters of pharmacokinetics among different groups.

Pharmacokinetic comparison of five tanshinones in normal and arthritic rats after oral administration of Huo Luo Xiao Ling Dan or its single herb extract by UPLC-MS/MS.

A fast, sensitive and reliable ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed and validated for simultaneous quantitation and pharmacokinetic study of five tanshinones (tanshinone I, tanshinone IIA, tanshinone IIB, dihydrotanshinone I, cryptotanshinone), the bio-active ingredients of Huo Luo Xiao Ling Dan (HLXLD) in rat plasma. After liquid-liquid extraction, chromatographic separation was accomplished on a Shim-pack XR-ODS column (75 × 3.0 mm, 2.2 µm particles) and eluted with a mobile phase consisting of acetonitrile-0.05% formic acid aqueous solution (80:20, v/v) at a flow rate of 0.4 mL/min, and the total run time was 7.0 min. The detection was performed on a triple quadrupole tandem mass spectrometry equipped with an electrospray ionization source in positive ionization and multiple reaction monitoring mode. The lower limits of quantification were 0.050-0.400 ng/mL for all the analytes. Linearity, precision and accuracy, the mean extraction recoveries and matrix effects all satisfied criteria for acceptance. This validated method was successfully applied to a comparative pharmacokinetic study of five bio-active components in rat plasma after oral administration of HLXLD or Salvia miltiorrhiza extract in normal and arthritic rats. The results showed that there were different pharmacokinetic characteristics among different groups. Copyright © 2016 John Wiley & Sons, Ltd.

Metabolites identification of Huo Luo Xiao Ling Dan in rat urine by UPLC coupled with electrospray ionization time-of-flight mass spectrometry.

Huo Luo Xiao Ling Dan (HLXLD), a Chinese herbal formula, is used in folk medicine for the treatment of arthritis and other chronic inflammatory diseases. However, the in vivo integrated metabolism of its multiple components remains unknown. In this paper, an ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS) method was developed for detection and identification of HLXLD metabolites in rat urine at high and normal clinical dosages. The prototype constituents and their metabolites in urine were analyzed. The mass measurements were accurate within 8 ppm, and subsequent fragment ions offered higher quality structural information for interpretation of the fragmentation pathways of various compounds. A total of 85 compounds were detected in high dosages urine samples by a highly sensitive extracted ion chromatograms method, including 31 parent compounds and 54 metabolites. Our results indicated that phase 2 reactions (e.g. glucuronidation, glutathionidation and sulfation) were the main metabolic pathways of lactones, alkaloids and flavones, while phase I reactions (e.g. hydrogenation and hydroxylation) were the major metabolic reaction for coumarins, paeoniflorin and iridoids. This investigation provided important structural information on the metabolism of HLXLD and provided scientific evidence to obtain a more comprehensive metabolic profile.

Simultaneous determination of four secoiridoid and iridoid glycosides in rat plasma by ultra performance liquid chromatography-tandem mass spectrometry and its application to a comparative pharmacokinetic study.

A simple, reliable and rapid ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous quantification of four secoiridoid (gentiopicroside, swertiamarin, sweroside) and iridoid glycosides (loganic acid), the bio-active ingredients in rat plasma. After liquid-liquid extraction, chromatographic separation was accomplished on a Shim-pack XR-ODS column with a mobile phase consisting of methanol and 0.1% formic acid in water. A triple quadrupole tandem mass spectrometry equipped with an electrospray ionization source was used as detector operating both in positive and negative ionization mode and operated by multiple-reaction monitoring scanning. The lower limits of quantitation were 0.25-30 ng/mL for all the analytes. Both intra-day and inter-day precision and accuracy of analytes were well within acceptance criteria (±15%). The mean extraction recoveries of analytes and internal standard (amygdalin) from rat plasma were all >71.4%. The validated method was successfully applied to a comparative pharmacokinetic study of four analytes in rat plasma between normal and arthritic rats after oral administration of Huo Luo Xiao Ling Dan and Gentiana macrophylla extract, respectively. Results showed significant differences in pharmacokinetic properties of the analytes among the different groups.