Last data update: Aug 15, 2025. (Total: 49733 publications since 2009)
| Records 1-4 (of 4 Records) |
| Query Trace: Ngac P[original query] |
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| Mouth level intake of nicotine from three brands of little filtered cigars with widely differing product characteristics among adult consumers
Ashley DL , Zhu W , Watson CH , Bravo R , Ngac PK , Valentin-Blasini L , Pickworth WB , Kurti AN , Cunningham C , Blount BC . Chem Res Toxicol 2023 36 (1) 43-52 Little filtered cigars are tobacco products with many cigarette-like characteristics. However, despite cigars falling under the U.S. Food and Drug Administration regulatory authority, characterizing flavors, which are still allowed in little filtered cigars, and filter design may influence how people use the products and the resulting exposure to harmful and potentially harmful constituents. We estimated nicotine mouth level intake (MLI) from analyses of little cigar filter butt solanesol levels, brand characteristics, carbon monoxide boost, and puff volume in 48 dual cigarette/cigar users during two repeat bouts of ad lib smoking of three little filtered cigar brands. Mean nicotine MLI for the three brands was significantly different with Swisher Sweets (0.1% ventilation) Cherry at 1.20 mg nicotine, Cheyenne Menthol (1.5%) at 0.63 mg, and Santa Fe unflavored (49%) at 0.94 mg. The association between nicotine MLI and puff volume was the same between Cheyenne Menthol and Santa Fe unflavored. However, these were different from Swisher Sweets Cherry. At least five main factors─flavor, ventilation, filter design, nicotine delivery related to tar, and user puff volume─may directly or indirectly impact MLI and its association with other measures. We found that users of little filtered cigars that have different filter ventilation and flavor draw dissimilar amounts of nicotine from the product, which may be accompanied by differences in exposure to other harmful smoke constituents. |
| Early changes in puffing intensity when exclusively using open-label very low nicotine content cigarettes
Watson C , Bravo Cardenas R , Ngac P , Valentin-Blasini L , Blount BC . Nicotine Tob Res 2022 24 (11) 1798-1802 INTRODUCTION: In response to reducing cigarette nicotine content, people who smoke could attempt to compensate by using more cigarettes or by puffing on individual cigarettes with greater intensity. Such behaviors may be especially likely under conditions where normal nicotine content (NNC) cigarettes are not readily accessible. The current within-subject, residential study investigated whether puffing intensity increased with very low nicotine content (VLNC) cigarette use, relative to NNC cigarette use, when no other nicotine products were available. METHODS: Sixteen adults who smoke daily completed two 4-night hotel stays in Charleston, South Carolina (U.S.) in 2018 during which only NNC or only VLNC cigarettes were accessible. We collected the filters from all smoked cigarettes and measured the deposited solanesol to estimate mouth-level nicotine delivery per cigarette. These estimates were averaged within and across participants, per each 24-hour period. We then compared the ratio of participant-smoked VLNC and NNC cigarette mouth-level nicotine to the ratio yielded by cigarette smoking machines (when puffing intensity is constant). RESULTS: Average mouth-level nicotine estimates from cigarettes smoked during the hotel stays indicate participants puffed VLNC cigarettes with greater intensity than NNC cigarettes in each respective 24-hour period. However, this effect diminished over time (p<0.001). Specifically, VLNC puffing intensity was 40.0% (95% CI: 29.9, 53.0) greater than NNC puffing intensity in the first period, and 16.1% (95% CI: 6.9, 26.0) greater in the fourth period. CONCLUSION: Average puffing intensity per cigarette was elevated with exclusive VLNC cigarette use, but the extent of this effect declined across four days. IMPLICATIONS: In an environment where no other sources of nicotine are available, people who smoke daily may initially attempt to compensate for cigarette nicotine reduction by puffing on individual cigarettes with greater intensity. Ultimately, the compensatory behavior changes required to achieve usual nicotine intake from VLNC cigarettes are drastic and unrealistic. Accordingly, people are unlikely to sustain attempts to compensate for very low cigarette nicotine content. |
| First things first: a step in the right direction for the preanalytical phase of thiamine measurements
Pfeiffer CM , Fazili Z , Mineva EM , Ngac PK . Am J Clin Nutr 2021 114 (3) 829-830 The 2018 roadmap for global control programs for thiamine deficiency disorders calls out the lack of biochemical population data on thiamine status (1). This report states that “urgent public health responses are warranted in high-risk regions, considering the contribution of thiamine deficiency to infant mortality and research suggesting that even subclinical thiamine deficiency in childhood may have lifelong neurodevelopmental consequences.” This situation poses a bit of a chicken and egg dilemma, as investigators need suitable analytical methods to produce high-quality biomarker data and policymakers need comparable and interpretable biomarker data to develop policies and evaluate their impact. Furthermore, analytical methods need to be paired with practical preanalytical conditions that allow for the collection and generation of valid biological specimens. For years, the field of thiamine research has been hampered due to the labile physiochemical properties of thiamine compounds and the lack of simple, yet reliable, analytical methods. |
| Determination of Free Solanesol Levels in Cigarette Filters by Liquid Chromatography-Mass Spectrometry
Bravo Cardenas R , Ngac P , Watson C , Valentin-Blasini L . J Anal Toxicol 2021 46 (5) 549-558 Solanesol, a naturally occurring constituent of tobacco, has been utilized as a good marker for environmental tobacco smoke particulate and as a non-invasive predictor of mainstream cigarette smoke tar and nicotine intake under naturalistic smoking conditions. A fast and accurate method for measuring free solanesol to assess tobacco smoke exposure is highly desirable. We have developed and validated a new environmentally friendly, high throughput method for measuring solanesol content in discarded cigarette filter butts. The solanesol deposited in the used filters can be correlated with mainstream smoke deliveries of nicotine and total particle matter (TPM) to estimate constituent delivery to smokers. A portion of filter material is removed from cigarette butts after machine smoking, spiked with internal standard solution, extracted, and quantitatively analyzed using reverse phase liquid chromatography coupled to a triple quadrupole mass spectrometer. The new method incorporates a 48-well plate format for automated sample preparation that reduces sample preparation time and solvent use and increases sample throughput 10-fold compared to our previous method. Accuracy and precision were evaluated by spiking known amounts of solanesol on both clean and smoked cigarette butts. Recoveries exceeded 93% at both low and high spiking levels. Linear solanesol calibration curves ranged from 1.9 to 367 µg/butt with a 0.05 µg/butt limit of detection. |
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