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Minigastrin
Minigastrin (also mini gastrin) is a form of gastrin. Its sequence is H-Leu-Glu-Glu-Glu-Glu-Glu-Ala-Tyr-Gly-Trp-Met-Asp-Phe-NH2. Minigastrin is a potential therapeutic agent for thyroid carcinoma by targeting cancer-promoting cholecystokinin receptors. Applications ''Peptide Receptor Radionuclide Therapy (PRRT)'' A radioactively labeled analogue of minigastrin, PP-F11, conjugated with NOTA, DOTA, or NODAGA, was studied to view the effects they have on peptide receptor radionuclide therapy (PRRT) and cancer cell tracing. When mice with CCK2 tumors were injected with 64Cu-labeled DOTA-PP-F11, NOTA-PP-F11, and NODAGA-PP-F11, the mice labeled with NOTA displayed a tumor uptake of 7.20 ± 0.44% ID/g and a high tumor-to-blood ratio. Further studies are being investigated on how to reduce the background levels to obtain clearer images. The inhibition of rapamycin Sirolimus, also known as rapamycin and sold under the brand name Rapamune among others, is a macrolide compound that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastrin
Gastrin is a peptide hormone that stimulates secretion of gastric acid (HCl) by the parietal cells of the stomach and aids in gastric motility. It is released by G cells in the pyloric antrum of the stomach, duodenum, and the pancreas. Gastrin binds to cholecystokinin B receptors to stimulate the release of histamines in enterochromaffin-like cells, and it induces the insertion of K+/H+ ATPase pumps into the apical membrane of parietal cells (which in turn increases H+ release into the stomach cavity). Its release is stimulated by peptides in the lumen of the stomach. Physiology Genetics In humans, the ''GAS'' gene is located on the long arm of the seventeenth chromosome (17q21). Synthesis Gastrin is a linear peptide hormone produced by G cells of the duodenum and in the pyloric antrum of the stomach. It is secreted into the bloodstream. The encoded polypeptide is preprogastrin, which is cleaved by enzymes in posttranslational modification to produce progastri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thyroid Carcinoma
Thyroid neoplasm is a neoplasm or tumor of the thyroid. It can be a benign tumor such as thyroid adenoma, or it can be a malignant neoplasm (thyroid cancer), such as papillary, follicular, medullary or anaplastic thyroid cancer.Hu MI, Vassilopoulou-Sellin R, Lustig R, Lamont JP"Thyroid and Parathyroid Cancers"in Pazdur R, Wagman LD, Camphausen KA, Hoskins WJ (EdsCancer Management: A Multidisciplinary Approach 11 ed. 2008. Most patients are 25 to 65 years of age when first diagnosed; women are more affected than men. The estimated number of new cases of thyroid cancer in the United States in 2023 is 43,720 compared to only 2,120 deaths. Of all thyroid nodules discovered, only about 5 percent are cancerous, and under 3 percent of those result in fatalities. Diagnosis The first step in diagnosing a thyroid neoplasm is a physical exam of the neck area. If any abnormalities exist, a doctor needs to be consulted. A family doctor may conduct blood tests, an ultrasound, and nuclear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cholecystokinin Receptor
Cholecystokinin receptors or CCK receptors are a group of G-protein coupled receptors which bind the peptide hormones cholecystokinin (CCK) and gastrin. There are two different subtypes CCKA and CCKB which are ~50% homologous: Various cholecystokinin antagonist A cholecystokinin receptor antagonist is a specific type of receptor antagonist which blocks the receptor sites for the peptide hormone cholecystokinin (CCK). Classification There are two subtypes of this receptor known at present, defined as ...s have been developed and are used in research, although the only drug of this class that has been widely marketed to date is the anti-ulcer drug proglumide. References External links * G protein-coupled receptors {{Cell-biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioactive Tracer
A radioactive tracer, radiotracer, or radioactive label is a synthetic derivative of a natural compound in which one or more atoms have been replaced by a radionuclide (a radioactive atom). By virtue of its radioactive decay, it can be used to explore the mechanism of chemical reactions by tracing the path that the radioisotope follows from reactants to products. Radiolabeling or radiotracing is thus the radioactive form of isotopic labeling. In biological contexts, experiments that use radioisotope tracers are sometimes called radioisotope feeding experiments. Radioisotopes of hydrogen, carbon, phosphorus, sulfur, and iodine have been used extensively to trace the path of biochemical reactions. A radioactive tracer can also be used to track the distribution of a substance within a natural system such as a cell or tissue, or as a flow tracer to track fluid flow. Radioactive tracers are also used to determine the location of fractures created by hydraulic fracturing in nat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptide Receptor Radionuclide Therapy
Peptide receptor radionuclide therapy (PRRT) is a type of radionuclide therapy, using a radiopharmaceutical that targets peptide receptors to deliver localised treatment, typically for neuroendocrine tumours (NETs). Mechanism A key advantage of PRRT over other methods of radiotherapy is the ability to target delivery of therapeutic radionuclides directly to the tumour or target site. This works because some tumours have an abundance (overexpression) of peptide receptors, compared to normal tissue. A radioactive substance can be combined with a relevant peptide (or its analogue) so that it preferentially binds to the tumour. With a gamma emitter as the radionuclide, the technique can be used for imaging with a gamma camera or PET scanner to locate tumours. When paired with alpha or beta emitters, therapy can be achieved, as in PRRT. The current generation of PRRT targets somatostatin receptors, with a range of analogue materials such as octreotide and other DOTA compounds. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sirolimus
Sirolimus, also known as rapamycin and sold under the brand name Rapamune among others, is a macrolide compound that is used to coat coronary stents, prevent organ transplant rejection, treat a rare lung disease called lymphangioleiomyomatosis, and treat perivascular epithelioid cell tumour (PEComa). It has immunosuppressant functions in humans and is especially useful in preventing the rejection of kidney transplants. It is a mammalian target of rapamycin (mTOR) kinase inhibitor that reduces the sensitivity of T cells and B cells to interleukin-2 (IL-2), inhibiting their activity. This compound also has a use in cardiovascular drug-eluting stent technologies to inhibit restenosis. It is produced by the bacterium '' Streptomyces hygroscopicus'' and was isolated for the first time in 1972, from samples of ''Streptomyces hygroscopicus'' found on Easter Island. The compound was originally named rapamycin after the native name of the island, Rapa Nui. Sirolimus was initially deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Everolimus
Everolimus, sold under the brand name Afinitor among others, is a medication used as an immunosuppressant to prevent rejection of organ transplants and as a targeted therapy in the treatment of renal cell cancer and other tumours. This compound also has a use in cardiovascular drug-eluting stent technologies to inhibit restenosis. It is the 40-''O''-(2-hydroxyethyl) derivative of sirolimus and works similarly to sirolimus as an inhibitor of mammalian target of rapamycin (mTOR). It is marketed by Novartis under the trade names Zortress (US) and Certican (European Union and other countries) in transplantation medicine, and as Afinitor (general tumours) and Votubia (tumours as a result of Tuberous Sclerosis Complex (TSC)) in oncology. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication. Medical uses Everolimus is approved for various conditions: * Advanced kidney cancer (US FDA approved in March 2009) * Prevention of org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
