Jeffrey Billings
University at Buffalo
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Featured researches published by Jeffrey Billings.
International Journal of Radiation Applications and Instrumentation. Part B. Nuclear Medicine and Biology | 1988
Hank Farn-Iuan Kung; Yu Zhi Guo; Jeffrey Billings; X. Xu; Robert H. Mach; Monte Blau; R.E. Ackerhalt
A new CNS D-2 dopamine receptor imaging agent [125I]IBZM, (S)-3-[125I]-iodo-N-[(1-ethyl-2-pyrrolidinyl)] methyl-2-hydroxy-6-methoxybenzamide, was prepared by either an exchange reaction or by the chloramine-T method. After an i.v. injection, the agent easily passed through the blood-brain barrier and localized in the rat brain. At 2, 15, 30 and 60 min after the injection, the brain uptake was 2.9, 2.3, 1.8 and 0.7% dose/organ, respectively. Regional uptake ratio of striatum/cerebellum (target to nontarget ratio) increased from 1.4 at 30 s to 10.3 at 2 h after the i.v. injection. Digital autoradiography of rat brain sections showed high regional uptake in the caudate putamen and accumbens nucleus, areas known to have a high concentration of the D-2 dopamine receptor. The specific uptake at the D-2 dopamine receptor site was blocked by pretreatment with spiperone, a selective D-2 antagonist. When labeled with 123I (t1/2 = 13 h, 159 keV), [123I]IBZM may be useful for imaging the CNS D-2 dopamine receptor.
International Journal of Radiation Applications and Instrumentation. Part B. Nuclear Medicine and Biology | 1988
Hank Farn-Iuan Kung; Jeffrey Billings; Yu Zhi Guo; Robert H. Mach
In vivo biodistribution of S- and R-isomers of [125I]IBZM in rats showed a significant initial brain uptake (3.20 and 2.67% dose/organ at 2 min, respectively). The wash-out from the brain was slower for the S-isomer. The striatum to cerebellum ratio for [125I]S-IBZM decreased with an increasing dose of cold carrier or spiperone, suggesting that the brain uptake is stereospecific and saturable, and may be related to the binding of D-2 dopamine receptors. In a dual isotope digital autoradiography study [125I]IBZM and [3H]NMSP(N-methylspiperone) show comparable regional cerebral distribution in rats.
Journal of The Chemical Society, Chemical Communications | 1991
Lynn C. Francesconi; Bo-Li Liu; Jeffrey Billings; Patrick J. Carroll; Grazyna Graczyk; Hank F. Kung
The neutral gallium complex of a bisaminoethanethiol ligand has a square pyramidal coordination geometry with Ga–N and Ga–S bonds.
International Journal of Radiation Applications and Instrumentation. Part B. Nuclear Medicine and Biology | 1987
Bo-Li Liu; Hank Farn-Iuan Kung; Jeffrey Billings; Monte Blau
Kinetics and mechanism of isotope exchange reaction between [82Br]bromide anion and 4-bromoantipyrine (BrAP), and the iodine-bromine exchange reaction between [125I]iodide anion and BrAP were studied. The preparation of [82Br]BrAP followed by exponential exchange law, the kinetics of the exchange reaction is a second-order reaction with an activation energy of 23.3 kcal/mol. The optimal exchange condition for halogen exchange between [125I]iodide and BrAP was by a hydrothermal melt method at 110 degrees C and 5 min reaction time. The partition coefficient at pH 7.0 for IAP and BrAP was 20.9 and 13.5, respectively. However, BrAP, which displayed the lower partition coefficient, showed higher brain uptake in rats than that for IAP (2.0% dose/organ vs 1.74% dose/organ), at 2 min after an i.v. injection.
The Journal of Nuclear Medicine | 1989
Hank F. Kung; Sangren Pan; Mei-Ping Kung; Jeffrey Billings; Ravindra Kasliwal; John Reilley; Abass Alavi
The Journal of Nuclear Medicine | 1990
Hank F. Kung; Abass Alavi; Wei Chang; Mei-Ping Kung; John W. Keyes; Michael G. Velchik; Jeffrey Billings; Sangren Pan; Richard Noto; Adriana Rausch; John Reilley
The Journal of Nuclear Medicine | 1984
Hank F. Kung; M. Molnar; Jeffrey Billings; Robert Wicks; Monte Blau
Journal of Medicinal Chemistry | 1989
Hank F. Kung; Yu Zhi Guo; Chi Chou Yu; Jeffrey Billings; Vinayakam Subramanyam; Joseph C. Calabrese
The Journal of Nuclear Medicine | 1990
Mei-Ping Kung; Hank F. Kung; Jeffrey Billings; Yunyun Yang; Raymond Murphy; Abass Alavi
Journal of Medicinal Chemistry | 1985
Hank F. Kung; Yu Cc; Jeffrey Billings; Molnar M; Monte Blau