HealthyNCT01399944
The Molecular Basis for a Broad Range of Phenotypes Related to hTAS2R38
An observational study of Healthy, run by Monell Chemical Senses Center at 1 site in United States.
Trial summary
This single-site, within-subject, experimental study is designed to test the hypothesis that individuals express taste receptors differently and have different sensitivities to bitter taste samples, which results from uneven expression. Subjects will include 100 racially and ethnically diverse, healthy adults. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- How many people
- 70 participants
- Where
- 1 siteUnited States
- Study dates
- Jul 2011to Jun 2013
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Adults of all races and both genders (N=100) will be involved in the proposed research. Typically, our population of subjects is approximately 45% African American, 45% Caucasian, 6% Hispanic, and 4% Asian. This increased representation of under-represented minorities in our subject populations is reflective of the greater Philadelphia region and has been achieved, in part, through our outreach efforts advertising in local newspapers throughout the city.
Who may be able to join
- Key inclusion criteria include age 18-40 years; English speaking, and good health at the time of study participation.
Who cannot join
- Key exclusion criteria include cigarette smoking, which alters taste perception, oral disease and subjects undergoing Coumadin therapy. Subjects showing signs of oral disease, including tongue lesions or xerostomia will be excluded from tongue biopsy and therefore excluded from the study. Subjects undergoing Coumadin therapy will be excluded from tongue biopsy due to the risk of bleeding, and therefore excluded from the study. Subjects will not be excluded because of economic status, gender, race or ethnicity.
Trial locations and contacts
1 site in 1 country.
United States1 site
Monell Chemical Senses Center
Philadelphia, Pennsylvania, 19104
About this study
This single-site, within-subject, experimental study is designed to test the hypothesis that individuals express taste receptors differently and have different sensitivities to bitter taste samples, which results from uneven expression. Subjects will include 100 racially and ethnically diverse, healthy adults. All subjects will provide saliva samples for genetic analysis and undergo taste testing with common psychophysical stimuli. From the pool of 100 subjects, 36 subjects from the common heterozygous group (PAV/AVI) and two from each homozygous group (AVI/AVI, nontaster and PAV/PAV, taster) will be invited to return for two additional sessions. During both sessions the investigators will 1) measure bitterness thresholds for PROP, a common psychophysical stimulus; 2) measure bitterness perception of several vegetables; 3) obtain a saliva sample and 4) collect taste papillae. The investigators will then isolate DNA and RNA from the taste papillae and isolate DNA from saliva to evaluate molecular differences over time and between individuals and how it relates to taste psychophysics. All psychophysical and cellular measurements will be done during both sessions so that the investigators can determine how much variation is observed over a one-week time period in both cellular phenotype and psychophysical phenotype.
- Conditions
- Healthy
- Keywords
- bitter taste, psychophysics, genetics, epigenetics, bitterness sensitivity
What is being measured
The primary outcome is the main question the study is designed to answer.
Bitter taste thresholds
Thresholds for propylthiouracil (PROP) will be measured using modified Harris-Kalmus recognition thresholds.
Measured: 2 days of testing (2 hours each)
Taste intensity and hedonic ratings of vegetables
Subjects will rate the intensity of five basic taste qualities (bitter, salt, sweet, sour, umami) and the liking of PROP, urea, quinine, caffeine, denatonium solutions and pureed vegetables using the general labelled magnitude scale (gLMS)
Measured: 3 days of testing (1-2 hours each)
TAS2R Genotype
Genotype of several TAS2Rs will be determined from DNA extracted from a saliva sample.
Measured: 1 day of testing (1-1.5 hours)
mRNA expression levels
Expression of taste and related genes will be determined from mRNA extracted from human taste tissue obtained via tongue biopsy.
Measured: 2 days of testing (2 hours each)
Secondary outcomes (2)
Dietary habits
Subjects will complete a 24 hour diet recall on 2 days of testing.
Measured: 2 days (2 hours each)
biometrics
Height, weight, blood pressure and bioimpedance measurements will be taken.
Measured: 1 day (1-1.5 hours)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Jul 2011 (estimated)
- Study startJul 2011
- Primary completionJun 2013
- Study completionJun 2013
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for HealthyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Cross-sectional
- Enrolment
- 70 participants (actual)
Sponsor and investigators
- Lead sponsor
- Monell Chemical Senses Center
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute on Deafness and Other Communication Disorders (NIDCD)
- Responsible party
- Principal investigator, Julie A. Mennella, Monell Chemical Senses Center
- Investigators
- Julie A. Mennella, PhD, Principal investigator, Monell Chemical Senses Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01399944
- Sponsor's protocol ID
- 813211
- Other IDs
- F32DC011975-01A1, R01DC011287-01
- Status last verified
- Dec 2017
- First submitted
- 20 Jul 2011
- Last updated
- 18 Dec 2017
- Results posted
- No
- Data monitoring committee
- No
Publications
Lipchock SV, Mennella JA, Spielman AI, Reed DR. Human bitter perception correlates with bitter receptor messenger RNA expression in taste cells. Am J Clin Nutr. 2013 Oct;98(4):1136-43. doi: 10.3945/ajcn.113.066688. Epub 2013 Sep 11.
PubMed 24025627
Study at a glance
From the registry record, last updated by the sponsor on 18 Dec 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Molecular Basis for a Broad Range of Phenotypes Related to hTAS2R38
- ClinicalTrials.gov ID
- NCT01399944
- Acronym / sponsor ID
- 813211
- Conditions
- Healthy
- Keywords
- bitter taste, psychophysics, genetics, epigenetics, bitterness sensitivity
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 70 participants (actual)
- Lead sponsor
- Monell Chemical Senses CenterUniversity, hospital or other
- Collaborators
- National Institute on Deafness and Other Communication Disorders (NIDCD)
- Study start
- Jul 2011
- Primary completion
- Jun 2013 (actual)
- Study completion
- Jun 2013 (actual)
- First posted
- 22 Jul 2011 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This single-site, within-subject, experimental study is designed to test the hypothesis that individuals express taste receptors differently and have different sensitivities to bitter taste samples, which results from uneven expression. Subjects will include 100 racially and ethnically diverse, healthy adults. All subjects will provide saliva samples for genetic analysis and undergo taste testing with common psychophysical stimuli. From the pool of 100 subjects, 36 subjects from the common heterozygous group (PAV/AVI) and two from each homozygous group (AVI/AVI, nontaster and PAV/PAV, taster) will be invited to return for two additional sessions. During both sessions the investigators will 1) measure bitterness thresholds for PROP, a common psychophysical stimulus; 2) measure bitterness perception of several vegetables; 3) obtain a saliva sample and 4) collect taste papillae. The investigators will then isolate DNA and RNA from the taste papillae and isolate DNA from saliva to evaluate molecular differences over time and between individuals and how it relates to taste psychophysics. All psychophysical and cellular measurements will be done during both sessions so that the investigators can determine how much variation is observed over a one-week time period in both cellular phenotype and psychophysical phenotype.
Study design
- Observational model
- Case only
- Time perspective
- Cross-sectional
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Adults of all races and both genders (N=100) will be involved in the proposed research. Typically, our population of subjects is approximately 45% African American, 45% Caucasian, 6% Hispanic, and 4% Asian. This increased representation of under-represented minorities in our subject populations is reflective of the greater Philadelphia region and has been achieved, in part, through our outreach efforts advertising in local newspapers throughout the city.
Key inclusion criteria (1 listed)
- Key inclusion criteria include age 18-40 years; English speaking, and good health at the time of study participation.
Key exclusion criteria (1 listed)
- Key exclusion criteria include cigarette smoking, which alters taste perception, oral disease and subjects undergoing Coumadin therapy. Subjects showing signs of oral disease, including tongue lesions or xerostomia will be excluded from tongue biopsy and therefore excluded from the study. Subjects undergoing Coumadin therapy will be excluded from tongue biopsy due to the risk of bleeding, and therefore excluded from the study. Subjects will not be excluded because of economic status, gender, race or ethnicity.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Bitter taste thresholds
Time frame: 2 days of testing (2 hours each)
Thresholds for propylthiouracil (PROP) will be measured using modified Harris-Kalmus recognition thresholds.
Taste intensity and hedonic ratings of vegetables
Time frame: 3 days of testing (1-2 hours each)
Subjects will rate the intensity of five basic taste qualities (bitter, salt, sweet, sour, umami) and the liking of PROP, urea, quinine, caffeine, denatonium solutions and pureed vegetables using the general labelled magnitude scale (gLMS)
TAS2R Genotype
Time frame: 1 day of testing (1-1.5 hours)
Genotype of several TAS2Rs will be determined from DNA extracted from a saliva sample.
mRNA expression levels
Time frame: 2 days of testing (2 hours each)
Expression of taste and related genes will be determined from mRNA extracted from human taste tissue obtained via tongue biopsy.
2 secondary outcomes
Dietary habits
Time frame: 2 days (2 hours each)
biometrics
Time frame: 1 day (1-1.5 hours)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Dec 2017.
- Derived from this study: PubMed 24025627Lipchock SV, Mennella JA, Spielman AI, Reed DR. Human bitter perception correlates with bitter receptor messenger RNA expression in taste cells. Am J Clin Nutr. 2013 Oct;98(4):1136-43. doi: 10.3945/ajcn.113.066688. Epub 2013 Sep 11.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Julie A. Mennella, PhD principal investigator
Monell Chemical Senses Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Healthy, run by Monell Chemical Senses Center at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 18 Dec 2017. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Bitter taste thresholds (time frame: 2 days of testing (2 hours each)). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01399944, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Dec 2017.