Development of a method for the determination of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol in urine of nonsmokers and smokers using liquid chromatography/tandem mass spectrometry

Molecularly imprinted polymers for selective extraction/microextraction of cancer biomarkers: A review

Over recent years, great efforts have been extensively documented in top scientific journals on the development of methods for early diagnosis, treatment, and monitoring of cancers which are prevalent critical diseases with a high mortality rate among men and women. The determination of cancer biomarkers using different optimum methodologies is one of the finest options for achieving these goals with more precision, speed, and at a lower cost than traditional clinical procedures. In this regard, while focusing on specific biomarkers, molecularly imprinted technology has enabled novel diagnostic techniques for a variety of diseases. Due to the well-known advantages of molecularly imprinted polymers (MIPs), this review focuses on the current trends of MIPs-based extraction/microextraction methods, specifically targeting cancer biomarkers from various matrices. These optimized methods have demonstrated high selectivity, accuracy, sorbent reusability, extraction recovery, and low limits of detection and quantification for a variety of cancer biomarkers, which are a powerful tool to provide early diagnosis, prognosis, and treatment monitoring, with potential clinical application expected soon. This review highlights the key progress, specific modifications, and strategies used for MIP synthesis. The future perspectives for cancer biomarkers purification and determination by fabricating MIP-based techniques are also discussed.

Counseling alone or in combination with nicotine replacement therapy for treatment of black non-daily smokers: a randomized trial

BACKGROUND AND AIMS

One-third of US tobacco users are non-daily smokers (NDS). Black NDS have strikingly high levels of nicotine and carcinogen exposure. No smoking cessation studies have been conducted with this high-risk group. This study compared the effectiveness in black NDS of smoking cessation counseling alone or in combination with the participant's choice of nicotine replacement therapy.

DESIGN

Two-arm parallel-group individually randomized clinical trial (allocation ratio of 2 : 1 intervention to control) SETTING: Academic medical and federally qualified health centers in three US cities.

PARTICIPANTS

Non-Hispanic black adult NDS receiving counseling with nicotine replacement therapy (C + NRT, n = 185) or counseling alone (C, n = 93).

INTERVENTIONS

Twelve weeks of in-person and telephone smoking cessation counseling in combination with nicotine replacement therapy (NRT; C + NRT) or counseling alone (C). All participants received five sessions of counseling; those randomized to C + NRT received their choice of nicotine gum, patch and/or lozenge after a 9-day product trial period. The target quit day was set at 2 weeks post-baseline for both groups.

MEASUREMENTS

Primary outcome was biochemically verified 30-day abstinence at week 12. Secondary outcomes were change in nicotine and carcinogen exposure [4-(methynitrosamino)-1-(3) pyridyle-1-butanol; NNAL] and tobacco consumption patterns.

FINDINGS

Abstinence was 11.4% in C + NRT and 8.6% in C [odds ratio (OR) = 1.4, 95% confidence interval (CI) = 0.6, 3.2, P = 0.48]. Both groups experienced significant reduction in NNAL (C + NRT: 53% reduction, C: 50% reduction, within-group P < 0.0001) but non-significant changes in cotinine (P = 0.69). C + NRT reported more days abstinent (P < 0.001) and fewer total cigarettes (P = 0.002) compared with C. There was no evidence of compensation with other tobacco products.

CONCLUSIONS

Among black non-daily smokers in the United States, there was no difference in abstinence between nicotine replacement therapy (NRT) and counseling alone. NRT led to greater increase in days abstinent and reduction in cigarettes, with no evidence of compensation from other sources of nicotine.

Effect of Long-term Nicotine Replacement Therapy vs Standard Smoking Cessation for Smokers With Chronic Lung Disease: A Randomized Clinical Trial

IMPORTANCE

Smokers with chronic obstructive pulmonary disease (COPD) have particular difficulty quitting. Long-term nicotine replacement therapy (LT-NRT) might offer a strategy for reducing harm from cigarettes and provide a pathway for later cessation.

OBJECTIVE

To compare the effect of LT-NRT vs standard smoking cessation (SSC) on exposure to cigarette smoke, harm related to smoking, and cessation among smokers with COPD.

DESIGN, SETTING, AND PARTICIPANTS

This unblinded, randomized clinical trial recruited smokers who self-reported a diagnosis of COPD at any level of readiness to quit from May 23, 2014, through November 30, 2015. The 12-month follow-up was completed December 6, 2016. Patients were recruited at a clinical research unit of an academic medical center. Analysis was based on intention to treat and performed from March 8 through November 30, 2017.

INTERVENTIONS

Standard smoking cessation treatment included 10 weeks of NRT and 4 follow-up counseling sessions for those willing to make a quit attempt. Long-term NRT included 12 months of NRT and 6 follow-up counseling sessions regardless of initial willingness to quit. Overall, 198 patients were randomized to SSC, and 197 were included in the primary analysis; 200 patients were randomized to LT-NRT, and 197 were included in the primary analysis.

MAIN OUTCOMES AND MEASURES

The primary outcome was 7-day abstinence verified by carbon monoxide (CO) levels at 12 months. Secondary outcomes included cigarettes smoked per day (CPD), exposure to CO, urinary excretion of 4-methylnitrosamino-1-3-pyridyl-1-butanol (NNAL) (a smoking-related carcinogen), and adverse events.

RESULTS

Among 398 patients who were randomized (59.8% female; mean [SD] age, 56.0 [9.3] years), the mean (SD) CPD was 23.1 (12.3). Twelve-month follow-up was completed by 373 participants (93.7%), and 394 (99.0%) were included in the primary analysis. At 12 months, CO-verified abstinence occurred in 23 of 197 participants (11.7%) in the SSC arm and 24 of 197 (12.2%) in the LT-NRT arm (risk difference, 0.5%; 95% CI, -5.9% to 6.9%). Continuing smokers in the SSC and LT-NRT arms had similar, significantly reduced harms caused by smoking, including cigarette consumption by 12.4 and 14.5 CPD, respectively, exhaled CO level by 5.5 and 7.8 ppm, respectively, and mean urinary NNAL excretion by 21.7% and 23.0%, respectively. In multivariate analyses, continuing smokers with greater adherence to NRT experienced less reduction in NNAL exposure. The frequency of major adverse cardiac events was similar in both groups.

CONCLUSIONS AND RELEVANCE

Similar rates of cessation and similar reductions in exposure to tobacco smoke resulted with LT-NRT and SSC. Among continuing smokers, ongoing use of NRT was not associated with reductions in smoke exposure.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02148445.

UPLC-MS/MS method for the determination of tobacco-specific biomarker NNAL, tamoxifen and its main metabolites in rat plasma

Cigarette smoke is known to interact with tamoxifen-metabolizing enzymes and transporters and potentially affect its treatment outcome. 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanol (NNAL) is an important metabolite of 4-(methylnitro-samino)-1-(3-pyridyl)-1-butanone (NNK) because it is frequently used as a biomarker to assess human smoke exposure. In order to study the potential pharmacokinetic interaction between cigarette smoke and tamoxifen in rats a UPLC-MS/MS method for the simultaneous determination of NNAL and tamoxifen along with its metabolites in rat plasma has been developed and validated. Analytes were extracted with methanol and separated on a HSS T3 column by a gradient elution with the mobile phase consisting of acetonitrile and water. The lower limits of quantitation ranged from 0.05 to 0.62 ng/mL. Precisions showed RSD <15.8% and accuracy in the range 80.6-116.0%. Mean analyte recoveries ranged from 76.9 to 108.4%. The method was successfully applied to study the effects of cigarette smoke condensate (CSC), NNK and benzo(a)pyrene pre-treatment on the pharmacokinetics of tamoxifen and its metabolites in rats. Significant effects of CSC, NNK, benzo(a)pyrene were observed on pharmacokinetics of tamoxifen and its metabolites. We also found that plasma NNAL levels are statistically significant correlated with plasma 4-hydroxy-tamoxifen and endoxifen.

Cigarette rod length and its impact on serum cotinine and urinary total NNAL levels, NHANES 2007-2010

INTRODUCTION

Research suggests that smokers of slim, long, or ultralong cigarettes may have a perception of reduced harm from their own brand. This study compared serum cotinine and urinary total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanonol (NNAL) levels among smokers of regular-sized (68-72mm), king-sized (79-88mm), and long (94-101mm) or ultralong (110-121mm) cigarettes.

METHODS

Nationally representative data from the 2007-2008 and 2009-2010 National Health and Nutrition Examination Survey were analyzed for 3,699 current smokers aged ≥20 years. Biomarker levels were summarized using geometric means (GMs). Multivariate linear regression analyses were performed to assess the effect of cigarette rod length on log-transformed serum cotinine and creatinine-adjusted urinary total NNAL levels.

RESULTS

The GM of serum cotinine level was higher among smokers of long/ultralong cigarettes (263.15ng/ml) compared with smokers of regular-sized (173.13ng/ml) or king-sized (213.79ng/ml) cigarettes. Similarly, the GM of creatinine-adjusted NNAL levels was higher among smokers of long/ultralong cigarettes (0.48ng NNAL/mg of creatinine) compared with smokers of regular-sized (0.34ng NNAL/mg of creatinine) or king-sized (0.33ng NNAL/mg of creatinine) cigarettes. After adjusting for potential confounders, mean cotinine and NNAL levels were both significantly higher among smokers of long/ultralong cigarettes compared with levels observed in smokers of either regular-sized or king-sized cigarettes. However, no significant differences were observed between smokers of regular-sized and king-sized cigarettes in mean levels of cotinine or NNAL.

CONCLUSIONS

Significantly elevated tobacco biomarker levels were observed among smokers of long/ultralong cigarettes compared with smokers of regular-sized or king-sized cigarettes. This underscores the need to educate the public about the dangers of all tobacco products.

High throughput liquid and gas chromatography-tandem mass spectrometry assays for tobacco-specific nitrosamine and polycyclic aromatic hydrocarbon metabolites associated with lung cancer in smokers

We developed and applied high throughput liquid and gas chromatography-tandem mass spectrometry (LC-MS/MS and GC-MS/MS) methods for the cigarette smoking-associated biomarkers 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and r-1,t-2,3,c-4-tetrahydroxy-1,2,3,4-tetrahydrophenanthrene (PheT), which are urinary metabolites of the carcinogenic tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and the polycyclic aromatic hydrocarbon phenanthrene. NNAL and PheT levels have been linked to lung cancer in previous studies of smokers. Confirmation of these relationships will require further molecular epidemiology studies, necessitating improved methodology applicable to large numbers of small urine samples. Furthermore, NNAL is excreted in urine either unconjugated or as an N- or O-glucuronide, but little data are available on the amounts of each in urine. For the high throughput analysis of NNAL, 3 aliquots were processed from each urine sample, one for the analysis of free NNAL, one for free NNAL plus NNAL-N-Gluc, and one for total NNAL (the sum of free NNAL, NNAL-N-Gluc, and NNAL-O-Gluc). Ninety-six well plate technology was used for sample enrichment by supported liquid extraction plates, mixed mode reverse-phase/cation exchange solid-phase extraction, and LC-MS/MS analysis. For the analysis of PheT, the urine samples were cleaned up by solid-phase extraction on styrene-divinylbenzene sorbent, silylated, and analyzed by GC-MS/MS, both in 96-well format. The methods were validated analytically with respect to accuracy and precision, and applied in an ongoing molecular epidemiology study of smokers. The amount of total NNAL in smokers' urine was (mean ± SD) 1.65 ± 2.13 pmol/mL (N = 2641). Free NNAL, NNAL-N-Gluc, and NNAL-O-Gluc represented (mean ± SD) 31 ± 11%, 22 ± 14%, and 48 ± 15% of total NNAL, respectively. The amount of PheT in smokers' urine was (mean ± SD) 1.43 ± 2.16 pmol/mL (N = 2613). The methodology described here should be widely applicable in future studies of tobacco use and cancer.