Ji: Wavefront synthesis imaging - Stanford University
The exocrine function of the pancreas results in a pancreatic juice that contains enzymes capable of breaking down the three major components of food-carbohydrates, fats, and proteins. The pancreas is divided into units called acini (acinus is Latin for berry). Each acinus is spherical, with enzyme-secreting cells surrounding a central space (Figure 50). Every enzyme-secreting cell synthesizes all the pancreatic enzymes. The enzymes pass into the center of the acini, entering the narrowest ducts of the branching secretory system. The enzymes pass by larger and larger ducts, eventually reaching the single pancreatic duct, or duct of Wirsung. The cells that line the duct system secrete water and bicarbonate ions, adding them to the enzymes. Consequently, the final pancreatic juice is alkaline. The volume of juice (approximately 2000 ml per 24-hour day) that is secreted is precisely enough to neutralize the acid contents of the stomach as they both enter the duodenum. Pancreatic enzymes are most effective when the contents of the duodenum are at a neutral pH. Chronic disease of the exocrine component of the pancreas results in deficiency of these pancreatic enzymes, giving rise to poor absorption of foodstuffs. The most conspicuous feature of malabsorption is the excretion of fats in feces.
Synthesis Imaging — CASA Documentation
36. Dumont RA, Deininger F, Haubner R, Maecke HR, Weber WA, Fani M. Novel 64Cu- and 68Ga-labeled RGD conjugates show improved PET imaging of αvβ3 integrin expression and facile radiosynthesis. 2011;52:1276-84
25. Maina T, Nikolopoulou A, Stathopoulou E, Galanis AS, Cordopatis P, Nock BA. [99mTc]Demotensin 5 and 6 in the NTS1-R-targeted imaging of tumours: synthesis and preclinical results. 2007;34:1804-14
14th Synthesis Imaging Workshop — Science Website
The main steps involved in developing a radiolabeled peptide for clinical application are as follows: (i) identification of the molecular target (receptor) with relevance to human disease and search for a lead peptide, which may be a natural or synthetic peptide, (ii) solid-phase peptide synthesis of a peptide or its analogs. In general, the design of a peptide is based on the structural composition of the endogenous ligand (natural peptide ligand), which exhibits high affinity for the corresponding receptor system. The natural peptide molecule is often structurally modified to produce a metabolically stabilized analog, which preserves most of the biological activity and receptor affinity of the original peptide molecule, (iii) covalent attachment of a chelating agent or a prosthetic group to the peptide either directly or through a linker/spacer group, (iv) radiolabeling that allow high labeling efficiency and high specific activity radiolabeled peptide preparation, (v) in vitro characterization, such as the binding of a radiopeptide with tumor cells, determination of receptor binding affinity, internalization into the tumor cells and dissociation from the tumor cells, (vi) in vivo evaluation to assess the biological behavior, biokinetics and tumor targeting capacity of the radiolabeled peptide in animal models. Many aspects should be considered for further development, such as the accumulation of radiolabeled peptide in target and non-target tissues, the rate and extent of the clearance of radioactivity from the body, the excretory pathway and in vivo stability of the radiolabeled peptide. (vii) The radiolabeled peptides, which successfully passed all the preclinical tests, after toxicological studies and established radiopharmaceutical preparation, may enter clinical studies in humans .
Synthesis imaging | Article about Synthesis imaging by …
The development of radiotracers for use in positron emission tomography (PET) requires consideration of biological and chemical issues . In the first place, the tracer must image a target of relevance to human disease either as a research tool to better understand the disease or as a clinical tool to benefit individual patients. The radiotracer must exhibit specific binding to the desired target, an appropriate signal to noise ratio to allow visualization of desired target over background, pharmacokinetics appropriate for the biological system and the incorporated radionuclide, and metabolic kinetics and clearance that do not interfere with image interpretation. In addition, the radiotracer must be synthesized using a chemical procedure that is robust and easily transferable to other facilities.
15/12/2017 · Looking for Synthesis imaging
We obtain by the synthesized beam by filling in our sampled real part = 1imaginarypart = 0()()= () = 1 + 0,