Faculty Bibliography

In rodents, CHRNs are involved in bitter taste transduction of nicotine and ethanol. Currently, it is not clear if CHRNs are expressed in human taste cells and if they play a role in transducing the bitter taste of nicotine and ethanol or in the synthesis and release of neurohumoral peptides. Accordingly, we investigated the expression and functional role of CHRNs in HBO cells. Using molecular techniques, we demonstrate that a subset of HBO cells express CHRNs that also co-express TRPM5, T1R3 or T2R38. Exposing HBO cells to nicotine or ethanol acutely or to nicotine chronically induced a differential increase in the expression of CHRN mRNA and protein in a dose- and time-dependent manner. Acutely exposing HBO cells to a mixture containing nicotine plus ethanol induced a smaller increase in CHRN mRNAs relative to nicotine or ethanol treatment alone. A subset of HBO cells responded to nicotine, acetylcholine and ATP with a transient increase in [Ca2+]i. Nicotine effects on [Ca2+]i were mecamylamine sensitive. Brain-derived neurotrophic factor (BDNF) protein was detected in HBO cells using ELISA. Acute nicotine exposure decreased BDNF in HBO cells and increased BDNF release in the medium. CHRNs were also detected in HEK293 cells by RT-PCR. Unlike HBO cells, CHRNs were localized in most of HEK293 cells and majority of HEK293 cells responded to nicotine and ethanol stimulation with a transient increase in [Ca2+]i. BDNF levels in HEK293 cells were significantly higher than in HBO cells but the nicotine induced release of BDNF in the media was a fraction of the BDNF cellular content. We conclude that CHRNs are expressed in TRPM5 positive HBO cells. CHRN mRNA expression is modulated by exposure to nicotine and ethanol in a dose- and time-dependent manner. Nicotine induces the synthesis and release of BDNF in HBO cells.

Using cigarettes and alternative tobacco products (ATPs) is associated with negative oral health outcomes, and dental health professionals are poised to help patients quit. The aim of this study was to determine dental, dental hygiene, and advanced dental students' use, knowledge, and beliefs about cigarettes and ATPs, including perceptions about their education in tobacco dependence treatment and counseling experience. All 1,783 students enrolled in the dental, dental hygiene, and postdoctoral dental programs at the New York University College of Dentistry were invited to participate in the survey in 2016. A total of 708 students at least partially completed the survey, for a response rate of 39.7%. In the results, 146 of the students (20.1%) reported ever using cigarettes, while 253 (35.7%) reported ever using any ATP. Regarding tobacco use intervention, the students reported they had not received enough training on ATPs, were neutral about cigarettes, and were somewhat confident and not so confident counseling a cigarette smoker or ATP user, respectively. By their fourth year, 77.8% of the dental students reported they had counseled someone to stop smoking cigarettes, but only 40.7% had counseled someone to stop using ATPs. Overall, all groups of students reported feeling more confident and had received more education on interventions for cigarettes than for ATPs (p<0.001). These students reported low confidence in helping people quit tobacco and did not perceive they had received enough training on intervening with patients on use of cigarettes and ATPs. These findings call for a revised tobacco education curriculum for dental, dental hygiene, and advanced dental students, focused on building knowledge and confidence for promoting tobacco dependence treatment.

Many readers may be familiar with patient-centered care, but they may not be familiar with the concept of person-centered care. Person-centered care implies knowing the patient as a person, not as just another patient or as a clinical requirement in dental school. Person-centered care gains the trust of the patient and is meaningful to the person because it respects his or her values, preferences, needs, and beliefs, emphasizing the individual's freedom of choice while promoting emotional and physical comfort. This article describes the concept of person-centered care, compares person-centered care with patient- and student-centered care, presents a vision of person-centered care in a clinic setting, discusses its opportunities and challenges in general, and outlines future topics of interest for the academic, research, and practicing dental communities, including opportunities for in-depth reviews and guidelines.

Digital textbooks are being used to reduce production and storage costs of printed copies, enhance usage, and include search capabilities, but the use of digital texts is not universally accepted. In 2001, the New York University College of Dentistry introduced a digital reference library, the VitalBook. Beginning in 2005, the college annually surveyed senior students and, from 2012, also surveyed alumni on their opinions and extent of use of the VitalBook. The aim of this study was to evaluate 12 years of students' perspectives and three years of alumni perspectives on the value of the VitalBook to their dental educational experience. Students were asked how frequently they used the VitalBook, if it was a good investment, if they would use it after graduation, and if they would recommend it to others. Alumni were asked the last three questions. This study reports the results from 4,105 students over 12 years (average response rate 95.3%) and 184 alumni over three years (average response rate 17.4%). The results indicated that students used the VitalBook on average 24% of their study time, but they were split regarding the other questions. The majority opinion in 2005 was negative on all questions. These opinions shifted to become more favorable to a peak in 2010, but declined since then to a more negative overall view of the VitalBook. A split opinion among students continued through 2016, with fewer recommending it although more considered it a good investment with plans to use it after graduation. Alumni mirrored their responses as students. These results suggest that, as more flexible and dynamic digitized reference systems emerge, the use of student-paid traditional digitized textbooks may become an even less favored choice.

Salty taste is one of the five basic tastes and is often elicited by NaCl. Because excess sodium intake is associated with many health problems, it could be useful to have salt taste enhancers that are not sodium based. In this study, the regulation of NaCl-induced responses was investigated in cultured human fungiform taste papillae (HBO) cells with five arginyl dipeptides: Ala-Arg (AR), Arg-Ala (RA), Arg-Pro (RP), Arg-Glu (RE), and Glu-Arg (ER); and two non-arginyl dipeptides: Asp-Asp (DD) and Glu-Asp (ED). AR, RA, and RP significantly increased the number of cell responses to NaCl, whereas no effect was observed with RE, ER, DD, or ED. We also found no effects with alanine, arginine, or a mixture of both amino acids. Pharmacological studies showed that AR significantly increased responses of amiloride-sensitive but not amiloride-insensitive cells. In studies using small interfering RNAs (siRNAs), responses to AR were significantly decreased in cells transfected with siRNAs against epithelial sodium channel ENaCalpha or ENaCdelta compared to untransfected cells. AR dramatically increased NaCl-elicited responses in cells transfected with NHE1 siRNA but not in those transfected with ENaCalpha or ENaCdelta siRNAs. Altogether, AR increased responses of amiloride-sensitive cells required ENaCalpha and ENaCdelta.

We investigated whether the abundance of bitter receptor mRNA expression from human taste papillae is related to an individual's perceptual ratings of bitter intensity and habitual intake of bitter drinks. Ratings of the bitterness of caffeine and quinine and three other bitter stimuli (urea, propylthiouracil, and denatonium benzoate) were compared with relative taste papilla mRNA abundance of bitter receptors that respond to the corresponding bitter stimuli in cell-based assays ( TAS2R4, TAS2R10, TAS2R38, TAS2R43, and TAS2R46). We calculated caffeine and quinine intake from a food frequency questionnaire. The bitterness of caffeine was related to the abundance of the combined mRNA expression of these known receptors, r = 0.47, p = .05, and self-reported daily caffeine intake, t(18) = 2.78, p = .012. The results of linear modeling indicated that 47% of the variance among subjects in the rating of caffeine bitterness was accounted for by these two factors (habitual caffeine intake and taste receptor mRNA abundance). We observed no such relationships for quinine but consumption of its primary dietary form (tonic water) was uncommon. Overall, diet and TAS2R gene expression in taste papillae are related to individual differences in caffeine perception.