Objective: The aim of the study was to assess the site of nicotine absorption during and after use of a nicotine-vapour inhaler compared with that after cigarette smoking.
Methods: Using a catheterisation technique, the nicotine plasma concentration-time profiles in arterial and jugular venous blood after using a nicotine inhaler were compared with those achieved after cigarette smoking a in seven healthy habitual smokers.
Results: After use of the inhaler, arterial nicotine concentrations rose slowly to a maximum level of 5. 9 +/- 1.5 ng/ml at a mean time to reach peak concentration (t(max)) of 9.0 +/- 1.1 min, whereas jugular venous nicotine levels peaked at 25.4 +/- 5.4 ng/ml at 6.7 +/- 0.3 min. The concentration-time curves indicate that the absorption occurs mainly via the mucosa of the oral cavity and the pharynx, and that there is minimal absorption via the lungs. In contrast, after smoking a cigarette, arterial nicotine plasma concentrations rose quickly to a maximum level of 49. 2 +/- 9.7 ng/ml after 4.0 +/- 0.6 min, while the maximum concentration of nicotine in the jugular vein was 22.4 +/- 3.9 ng/ml after 6.4 +/- 0.4 min, indicating primarily pulmonary absorption of nicotine.
Conclusion: Nicotine absorption after use of the vapour inhaler occurs primarily via the mucosa of the oral cavity; the absorption occurs slowly and the arterial nicotine concentration spike, typical of cigarette smoking, is avoided. Thus, the likelihood for abuse of the nicotine inhaler is probably small.
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http://dx.doi.org/10.1007/s002280050007 | DOI Listing |
J Voice
December 2024
Department of Duquesne-China Health Institute, John G. Rangos Sr. School of Health Sciences, Duquesne University, Pittsburgh, PA; Speech Science Laboratory, Faculty of Education, The University of Hong Kong, Hong Kong SAR, China.
Acupunct Med
October 2024
Department of Rehabilitation, The Third Xiangya Hospital, Central South University, Changsha, China.
Introduction: Consistency of liquid food plays an important role in managing patients with dysphagia, which can be objectively evaluated by using IDDSI Flow Test and consistometry. The present study established the relationship between IDDSI Flow Test and consistometric measures, and examined the measurement limitations of each test associated with thickened liquids prepared using starch-based and xanthan gum-based thickening agents.
Methods: Thirteen thickened liquid samples of consistency ranging from IDDSI Level 1 (mildly thick) to Level 3 (moderately thick) were prepared using starch-based and xanthan gum-based thickeners.
J Voice
June 2024
Duquesne-China Health Institute, John G. Rangos, Sr. School of Health Sciences, Duquesne University, Pittsburgh, Pennsylvania. Electronic address:
Objectives: Face masks have become important after the pandemic, but the change in voice when wearing a face mask is still unclear. The study investigated the effect of face masks on the acoustic and perceptual characteristics of voice quality associated with young and older Chinese adults.
Methods: Voice samples of the sustained vowel /a/ and continuous speech produced by 44 older and 61 young adults with and without an ASTM level-3 surgical face mask were recorded and analyzed.
Int J Tryptophan Res
May 2024
Applied Neurosciences Program, Peter Duncan Neurosciences Research Unit, St. Vincent's Centre for Applied Medical Research, Sydney, NSW, Australia.
Stem cells are ubiquitously found in various tissues and organs in the body, and underpin the body's ability to repair itself following injury or disease initiation, though repair can sometimes be compromised. Understanding how stem cells are produced, and functional signaling systems between different niches is critical to understanding the potential use of stem cells in regenerative medicine. In this context, this review considers kynurenine pathway (KP) metabolism in multipotent adult progenitor cells, embryonic, haematopoietic, neural, cancer, cardiac and induced pluripotent stem cells, endothelial progenitor cells, and mesenchymal stromal cells.
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