Dr. Rama Pichika has 30 years experience with several outstanding organic chemists of world renown and has 10 years experience in radiochemistry and radiopharmaceuticals. Dr. Pichika studied organic chemistry for 5 years with Dr. George Olah, Distinguished Professor in Organic Chemistry at the University of Southern California and Nobel Prize recipient. He has carried out a wide variety of organic reactions. Pichika has trained in the laboratories of Professor Michael Kilbourn of the University of Michigan and Professor Jogesh Mukherjee of University of California-Irvine. Dr. Pichika has got a patent on labeled alpha-4beta2 ligands and methods therefore. US Patent Number WO/2006/086068, publication date 08.17.2006, International Application Number PCT/US2005/045538. More over, Dr. Pichika had published a general method in Tetrahedron Letters for the synthesis of Z-allylic acetates having additional functional group such as a ketone or aldehyde, and has carried out a wide variety of organic reactions. He has developed several radiopharmaceuticals since coming to UCSD and has been key in filing INDs for DASB (SERT ligand), PIB (a plaque binding ligand), Raclopride (a D2/D3 ligand) and fallypride (D2/D3). The IND for DASB, Raclopride, PiB-1 and fallypride is approved.
His background should assure a high probability of success in the synthesis and validation of this new radiopharmaceutical. Dr. Pichika is presently working at the Sorrento Valley PET Center, where is prepares PET radiopharmaceuticals for clinical studies and develops the necessary information for filing INDs for additional radiopharmaceuticals. Those facilities will be available for preparing radioactive compounds. The synthetic work (cold chemistry) will take place in a nearby facility in the General Atomics building in Sorrento Valley, 3510 Dunhill Street, now called the UCSD Radiology Imaging Laboratory (RIL).
Dr. Pichika carried out synthesis of putative antagonists’ 18F-nifrolidine, 18F-nifrolene, 18F-nifene and 18F-nifzetidine as potential PET imaging agents for PET studies of the alpha4beta2 nicotine receptors which has been implicated in Alzheimer’s disease, schizophrenia, substance abuse and other disorders. The new 18F-fluoropropyl derivatives show promise as imaging agents for the alpha4beta2nAChR. Fluorine-18 labeled nifrolidine and nifzetidine have been prepared in good yields and high specific activities. In vitro study with 18F-nifrolidine and 18F-nifzetidine indicates selective high binding in the thalamus as well as binding in extrathalamus regions such as cortex, striatum, subiculum, lateral geniculate and other regions consistent with alpha4beta2 receptor distribution. In vivo studies indicate that 18F-nfrolidine and 18F-nifzetidine are relatively stable in vivo, cross the blood brain barrier, bind to receptors rich regions and are able to provide selectivity depending on receptor concentrations. Human studies with 18F-Fallypride: The intermediates and precursors were made for radiopharmaceutical 18F-fallypride synthesis. The synthesis of 18F-fallypride was carried out by nucleophilic displacement of the tosylate group in the chemical process control unit (CPCU). Human studies of dopamine D2/D3 receptors using 18F-fallypride-PET in normal volunteers and patients are being to evaluate brain distribution in striatal and extrastriatal regions.
Positron Emission Tomography (PET) Studies Investigating Serotonin Function in Anorexia Nervosa and Bulimia Nervosa, using Dopamine D2/3 receptor ([11C]raclopride) and Serotonin Transporter ([11C]DASB) ligands. The cause of eating disorders (EDs) is presumed to be complex and influenced by developmental, social, and biological processes. Twin, family, and genetic studies support the possibility that an underlying trait-related vulnerability places someone “at risk” for developing EDs. Preliminary data, using PET imaging technology, suggests that brain serotonin (5HT) and dopamine (DA) disturbances occur in ED. The purpose of these studies is to identify regional localization of alterations and shed light on the behavioral dynamics of 5HT and DA functional activity. Human studies with 11C-PiB-1 are an additional project that is part of the large multi-institution Alzheimer’s disease Neuroimaging Initiative (ADNI). The purpose of this study is to measure amyloidal in the brain. Amyloidal is a protein that is found in the brain in patients with Alzheimer’s disease at autopsy. We are interested in knowing whether it can be detected in control subjects or patients who have mild cognitive impairment (MCI) or Alzheimer’s disease (AD).
UCSD Center for Molecular Imaging
11388 Sorrento Valley Road, Suite 100
San Diego, CA 92121