Pandemics and education: A historical review
Major pandemics have tremendous effects on society. They precipitated the early decline of the Western Roman Empire and helped spread Christianity. There are countless such examples of infectious diseases altering the course of history. The impact of epidemics on education however is less well documented. This present historical account of the past 800 years looks specifically at how some aspects of education were shaped from the early medieval epidemics such as leprosy and the Black Plague to the Spanish Flu and COVID-19. Leprosy changed religious education, and the Black Plague may have contributed to the rise of medical schools, hospitals, public health education, and led to the implementation of lazarettos and the quarantine. The smallpox epidemic helped usher in public health education for immunization, while the 1918 Spanish Flu precipitated the rise of education by correspondence, and recently COVID-19 has catapulted remote digital learning to the forefront of higher education.
Sophorolipid Reduces Bitter Taste in Humans In Vivo and In Vitro
Restructuring of Dental Educationin a Post-COVID-19 Era
Zika virus infection in chemosensory cells
Zika virus (ZIKV) is an emerging virus belonging to the genus Flavivirus. ZIKV infection is a significant health concern, with increasing numbers of reports of microcephaly cases in fetuses and Guillain-BarrÃ© syndrome (GBS) in adults. Interestingly, chemosensory disturbances are also reported as one of the manifestations of GBS. ZIKV infects several human tissues and cell types in vitro and in vivo. However, there is no study demonstrating ZIKV infection and replication in chemosensory cells, including olfactory and taste cells. Taste papilla and olfactory cells are chemosensory receptor cells with unique histological, molecular, and physiological characteristics. Here we examined ZIKV infection (PRVABC59) in cultured human olfactory epithelial cells (hOECs) and fungiform taste papilla (HBO) cells in vitro, as well as in vivo mouse taste and olfactory epithelial and olfactory bulb tissues. Interestingly, while HBO cells showed resistance to ZIKV replication, hOECs were highly susceptible for ZIKV infection and replication. Further, we demonstrated the presence of ZIKV particles and expression of viral proteins in olfactory epithelium, as well as in olfactory bulb, but not in taste papillae, of immunocompromised mice (ifnar/-) infected with the PRVABC59 strain of ZIKV. These observations suggest that chemosensory cells in the olfactory neuroepithelium and olfactory bulb may be important tissues for ZIKV replication and dissemination.
The Teaching of Personalized Dentistry in North American Dental Schools: Changes from 2014 to 2017
The aim of this study was to assess the development of personalized dentistry in the curricula of North American dental schools from 2014 to 2017. In 2014, a web-based survey on personalized medicine/dentistry (PM/PD) was distributed to academic deans of all U.S. (n=65) and Canadian (n=10) dental schools with graduating classes. The results (n=42; 56% response rate) showed that few schools had plans for implementation of PM/PD at the time, even though the majority of respondents reported feeling that PM/PD should be taught in the curriculum and will impact clinical practice in the future. A three-year follow-up survey in 2017, sent to the same 75 schools, was designed to reassess the teaching/practice of PM/PD in dental schools in both didactic and clinical curricula. In the results of the 2017 survey (n=30; 40% response rate), the majority of respondents reported feeling that PM/PD should be taught in dental curricula. However, while most respondents indicated their schools did not teach PM/PD as a portion of their didactic curricula, they reported that specific pertinent PM/PD topics were taught as part of other courses in their curricula. The 2017 survey also evaluated the use of seven genetics-based and eight non-genetics-based PM/PD diagnostics in the schools' clinical curricula. Overall, non-genetics-based diagnostics were used more often than genetics-based diagnostics, and the use of genetics-based diagnostics was more prevalent in postgraduate than predoctoral clinics. Personalized dentistry will inevitably be part of the dental professional's future and should be reflected in basic science research, clinical settings, and dental school curricula in both predoctoral and postgraduate programs.
Mammalian Taste Cells Express Functional Olfactory Receptors
The peripheral taste and olfactory systems in mammals are separate and independent sensory systems. In the current model of chemosensation, gustatory, and olfactory receptors are genetically divergent families expressed in anatomically distinct locations that project to disparate downstream targets. Although information from the 2 sensory systems merges to form the perception of flavor, the first cross talk is thought to occur centrally, in the insular cortex. Recent studies have shown that gustatory and olfactory receptors are expressed throughout the body and serve as chemical sensors in multiple tissues. Olfactory receptor cDNA has been detected in the tongue, yet the presence of physiologically functional olfactory receptors in taste cells has not yet been demonstrated. Here we report that olfactory receptors are functionally expressed in taste papillae. We found expression of olfactory receptors in the taste papillae of green fluorescent protein-expressing transgenic mice and, using immunocytochemistry and real-time quantitative polymerase chain reaction experiments, the presence of olfactory signal transduction molecules and olfactory receptors in cultured human fungiform taste papilla (HBO) cells. Both HBO cells and mouse taste papilla cells responded to odorants. Knockdown of adenylyl cyclase mRNA by specific small inhibitory RNA and pharmacological block of adenylyl cyclase eliminated these responses, leading us to hypothesize that the gustatory system may receive olfactory information in the periphery. These results provide the first direct evidence of the presence of functional olfactory receptors in mammalian taste cells. Our results also demonstrate that the initial integration of gustatory and olfactory information may occur as early as the taste receptor cells.
Tissue-dependent expression of bitter receptor TAS2R38 mRNA
TAS2R38 is a human bitter receptor gene with a common but inactive allele; people homozygous for the inactive form cannot perceive low concentrations of certain bitter compounds. The frequency of the inactive and active form of this receptor is nearly equal in many human populations, and heterozygotes with one copy of the active form and one copy of the inactive form have the most common diplotype. However, even though they have the same genotype, heterozygotes differ markedly in their perception of bitterness, perhaps in part because of differences in TAS2R38 mRNA expression. Other tissues express this receptor too, including the nasal sinuses, where it contributes to pathogen defense. We therefore wondered whether heterozygous people had a similar wide range of TAS2R38 mRNA in sinonasal tissue and whether those with higher TAS2R38 mRNA expression in taste tissue were similarly high-expressers in nasal tissue. To that end, we measured gene expression by qPCR in taste and sinonasal tissue and found that expression abundance in one tissue was not related to the other. We confirmed the independence of expression in other tissues pairs expressing TAS2R38 mRNA, such as pancreas and small intestine, using autopsy data from the Genotype-Tissue Expression (GTEx) project (although people with high expression of TAS2R38 mRNA in colon also tended to have higher expression in the small intestine). Thus, taste tissue TAS2R38 mRNA expression among heterozygotes is unlikely to predict expression in other tissues, perhaps reflecting tissue-dependent function, and hence regulation, of this protein.
Sophorolipid Biosurfactants Activate Taste Receptor Type 1 Member 3-Mediated Taste Responses and Block Responses to Bitter Taste In Vitro and In Vivo
Sophorolipids (SL) are typically produced and secreted by select nonpathogenic yeast species (i.e., Candida) from renewable substrates. They are currently being used by industry on a limited basis in formulations for cleaning solutions as well as laundry and dishwashing detergents. Due to the nature of their chemical structure, it was hypothesized that SL would demonstrate taste-sensory properties. In this study, SL were produced via fermentation on a mixed substrate platform with glucose and either palmitic acid, stearic acid, or oleic acid using Candida (currently reclassified as Starmerella) bombicola ATCC 22214. The taste properties of SL were determined using a single-cell manual calcium imaging technique on cultured human fungiform taste papillae (HBO) cells. The results of those studies demonstrated that sweetener-responsive HBO cells also respond to SL, and these responses are mediated by the type 1 taste receptors 3 (T1R3), because they were blocked by lactisole (a T1R3 receptor-specific blocker). The involvement of the T1R3 receptor in SL recognition was confirmed via the chorda tympani nerve recording (CTNR) study in a (âˆ’/âˆ’) T1R3 knockout (KO) mouse model. We further demonstrated that SL are capable of blocking the bitter stimuli-elicited responses both in HBO cells and in the CTNR study. This is the first report demonstrating that SL have taste-sensory properties, which opens up numerous possibilities for practical applications of SL to ameliorate bitter tastes in foods and drugs and understand the potential source of dysgeusia in some patients.
Zika Virus Infection in Chemosensory Cells [Meeting Abstract]
Modulatory Effect of Arginyl Dipeptides on the Frequency of NaCl Elicited Responses in Cultured Human Fungiform Taste Papillae (HBO) Cells [Meeting Abstract]