Tatjana Abaffy

Positions:

Assistant Research Professor in Molecular Genetics and Microbiology

Molecular Genetics and Microbiology
School of Medicine

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Education:

Ph.D. 2000

University of Auckland (New Zealand)

Grants:

Publications:

The location of olfactory receptors within olfactory epithelium is independent of odorant volatility and solubility.

BACKGROUND: Our objective was to study the pattern of olfactory receptor expression within the dorsal and ventral regions of the mouse olfactory epithelium. We hypothesized that olfactory receptors were distributed based on the chemical properties of their ligands: e.g. receptors for polar, hydrophilic and weakly volatile odorants would be present in the dorsal region of olfactory epithelium; while receptors for non-polar, more volatile odorants would be distributed to the ventral region. To test our hypothesis, we used micro-transplantation of cilia-enriched plasma membranes derived from dorsal or ventral regions of the olfactory epithelium into Xenopus oocytes for electrophysiological characterization against a panel of 100 odorants. FINDINGS: Odorants detected by ORs from the dorsal and ventral regions showed overlap in volatility and water solubility. We did not find evidence for a correlation between the solubility and volatility of odorants and the functional expression of olfactory receptors in the dorsal or ventral region of the olfactory epithelia. CONCLUSIONS: No simple clustering or relationship between chemical properties of odorants could be associated with the different regions of the olfactory epithelium. These results suggest that the location of ORs within the epithelium is not organized based on the physico-chemical properties of their ligands.
Authors
Abaffy, T; Defazio, AR
MLA Citation
Abaffy, Tatjana, and Anthony R. Defazio. “The location of olfactory receptors within olfactory epithelium is independent of odorant volatility and solubility..” Bmc Res Notes, vol. 4, May 2011. Pubmed, doi:10.1186/1756-0500-4-137.
URI
https://scholars.duke.edu/individual/pub1120535
PMID
21548958
Source
pubmed
Published In
Bmc Research Notes
Volume
4
Published Date
Start Page
137
DOI
10.1186/1756-0500-4-137

A protocol for characterizing the impact of collateral flow after distal middle cerebral artery occlusion.

In humans and in animal models of stroke, collateral blood flow between territories of the major pial arteries has a profound impact on cortical infarct size. However, there is a gap in our understanding of the genetic determinants of collateral formation and flow, as well as the signaling pathways and neurovascular interactions regulating this flow. Previous studies have demonstrated that collateral flow between branches of the anterior cerebral artery (ACA) and the middle cerebral artery (MCA) can protect mouse cortex from infarction after middle cerebral artery occlusion. Because the number and diameter of collaterals varies among mouse strains and after transgenic manipulations, a combination of methods is required to control for these variations. Here, we report an inexpensive approach to characterizing the cerebrovascular anatomy, and in vivo monitoring of cerebral blood flow as well. Further, we introduce a new, minimally invasive method for the occlusion of distal MCA branches. These methods will permit a new generation of studies on the mechanisms regulating collateral remodeling and cortical blood flow after stroke.
Authors
Defazio, RA; Levy, S; Morales, CL; Levy, RV; Dave, KR; Lin, HW; Abaffy, T; Watson, BD; Perez-Pinzon, MA; Ohanna, V
MLA Citation
Defazio, R. Anthony, et al. “A protocol for characterizing the impact of collateral flow after distal middle cerebral artery occlusion..” Transl Stroke Res, vol. 2, no. 1, Mar. 2011, pp. 112–27. Pubmed, doi:10.1007/s12975-010-0044-2.
URI
https://scholars.duke.edu/individual/pub1120534
PMID
21593993
Source
pubmed
Published In
Translational Stroke Research
Volume
2
Published Date
Start Page
112
End Page
127
DOI
10.1007/s12975-010-0044-2

A case report - Volatile metabolomic signature of malignant melanoma using matching skin as a control.

Melanoma is the most serious form of skin cancer. The quest for melanoma diagnostic biomarkers is paramount since early detection of melanoma and surgical excision represent the only effective treatment of this capricious disease. Our recent study tested the hypothesis that melanoma forms a unique volatile signature that is different than control, healthy tissue. Here, we are reporting a case study, the analysis of the volatile metabolic signature of a malignant melanoma using matched, non-neoplastic skin tissue from the same patient as a control. This is a significant improvement in the methodology, since it is well known that diet, skin type, genetic background, age, sex and environment all contribute to individual variation in the skin volatile signature. In the present study, we have identified 32 volatile compounds; 9 volatile compounds were increased in melanoma when compared to normal skin and 23 volatile compounds were detected only in melanoma and not in normal skin. Out of these 32 compounds, 10 have been reported previously by our group, thus confirming our results and adding additional confidence in our untargeted metabolomics approach for detection of melanoma biomarkers.
Authors
Abaffy, T; Möller, M; Riemer, DD; Milikowski, C; Defazio, RA
MLA Citation
Abaffy, Tatjana, et al. “A case report - Volatile metabolomic signature of malignant melanoma using matching skin as a control..” J Cancer Sci Ther, vol. 3, no. 6, 2011, pp. 140–44. Pubmed, doi:10.4172/1948-5956.1000076.
URI
https://scholars.duke.edu/individual/pub1120533
PMID
22229073
Source
pubmed
Published In
Journal of Cancer Science & Therapy
Volume
3
Published Date
Start Page
140
End Page
144
DOI
10.4172/1948-5956.1000076

Differential volatile signatures from skin, naevi and melanoma: a novel approach to detect a pathological process.

BACKGROUND: Early detection of melanoma is of great importance to reduce mortality. Discovering new melanoma biomarkers would improve early detection and diagnosis. Here, we present a novel approach to detect volatile compounds from skin. METHODS AND FINDINGS: We used Head Space Solid Phase Micro-Extraction (HS-SPME) and gas chromatography/mass spectrometry (GC/MS) to identify volatile signatures from melanoma, naevi and skin samples. We hypothesized that the metabolic state of tissue alters the profile of volatile compounds. Volatiles released from fresh biopsy tissue of melanoma and benign naevus were compared based on their difference in frequency distribution and their expression level. We also analyzed volatile profiles from frozen tissue, including skin and melanoma. CONCLUSIONS: Three volatiles, 4-methyl decane, dodecane and undecane were preferentially expressed in both fresh and frozen melanoma, indicating that they are candidate biomarkers. Twelve candidate biomarkers evaluated by fuzzy logic analysis of frozen samples distinguished melanoma from skin with 89% sensitivity and 90% specificity. Our results demonstrate proof-of-principle that there is differential expression of volatiles in melanoma. Our volatile metabolomic approach will lead to a better understanding of melanoma and can enable development of new diagnostic and treatment strategies based on altered metabolism.
Authors
Abaffy, T; Duncan, R; Riemer, DD; Tietje, O; Elgart, G; Milikowski, C; DeFazio, RA
MLA Citation
Abaffy, Tatjana, et al. “Differential volatile signatures from skin, naevi and melanoma: a novel approach to detect a pathological process..” Plos One, vol. 5, no. 11, Nov. 2010. Pubmed, doi:10.1371/journal.pone.0013813.
URI
https://scholars.duke.edu/individual/pub1120536
PMID
21079799
Source
pubmed
Published In
Plos One
Volume
5
Published Date
Start Page
e13813
DOI
10.1371/journal.pone.0013813

Genetic elucidation of human hyperosmia to isovaleric acid.

The genetic basis of odorant-specific variations in human olfactory thresholds, and in particular of enhanced odorant sensitivity (hyperosmia), remains largely unknown. Olfactory receptor (OR) segregating pseudogenes, displaying both functional and nonfunctional alleles in humans, are excellent candidates to underlie these differences in olfactory sensitivity. To explore this hypothesis, we examined the association between olfactory detection threshold phenotypes of four odorants and segregating pseudogene genotypes of 43 ORs genome-wide. A strong association signal was observed between the single nucleotide polymorphism variants in OR11H7P and sensitivity to the odorant isovaleric acid. This association was largely due to the low frequency of homozygous pseudogenized genotype in individuals with specific hyperosmia to this odorant, implying a possible functional role of OR11H7P in isovaleric acid detection. This predicted receptor-ligand functional relationship was further verified using the Xenopus oocyte expression system, whereby the intact allele of OR11H7P exhibited a response to isovaleric acid. Notably, we also uncovered another mechanism affecting general olfactory acuity that manifested as a significant inter-odorant threshold concordance, resulting in an overrepresentation of individuals who were hyperosmic to several odorants. An involvement of polymorphisms in other downstream transduction genes is one possible explanation for this observation. Thus, human hyperosmia to isovaleric acid is a complex trait, contributed to by both receptor and other mechanisms in the olfactory signaling pathway.
Authors
Menashe, I; Abaffy, T; Hasin, Y; Goshen, S; Yahalom, V; Luetje, CW; Lancet, D
MLA Citation
Menashe, Idan, et al. “Genetic elucidation of human hyperosmia to isovaleric acid..” Plos Biol, vol. 5, no. 11, Oct. 2007. Pubmed, doi:10.1371/journal.pbio.0050284.
URI
https://scholars.duke.edu/individual/pub1120537
PMID
17973576
Source
pubmed
Published In
Plos Biology
Volume
5
Published Date
Start Page
e284
DOI
10.1371/journal.pbio.0050284