Metals, Rare Earth
Radioisotope Dilution Technique
Changes in myocardial blood flow and S-T segment elevation following coronary artery occlusion in dogs. (1/12)The relationship between regional blood flow and epicardial S-T segment elevation was studied in 26 open-chest anesthetized dogs with left anterior coronary artery ligations. Changes in myocardial blood flow, measured with 15 plus or minus 5mu (diameter) microspheres labeled with 141-Ce, 85-Sr, and 169-Yb, were correlated with summated S-T segment elevations 15 minutes, 1 hour, and 2 hours after coronary artery occlusion. In normal areas, myocardial blood flow was 113 plus or minus 5 ml/min 100 g- minus 1 and summated S-T segment elevation was 0.3 plus or minus 0.2 mv. Fifteen minutes after coronary artery occlusion in 26 dogs, S-T segment elevation was 5.7 plus or minus 0.7 mv over the center of the infarct and myocardial blood flow was 10 plus or minus 1 ml/min 100 g- minus 1; over the border zone, myocardial blood flow was 63 plus or minus 4 ml/min 100 g- minus 1 and S-T segment elevation was 3.1 plus or minus 0.1 mv. One third of the areas with a myocardial blood flow of 10 ml/min 100 g- minus 1 or less had no S-T segment elevation. In the center and border zones of the infarct in 9 dogs, myocardial blood flow increased from 11 plus or minus 2 and 67 plus or minus 8 ml/min 100 g- minus 1 15 minutes after occlusion to 20 plus or minus 4 and 84 plus or minus 12 ml/min 100 g- minus 1, respectively, 2 hours after coronary artery occlusion. These increases were not associated with a significant reduction in summated S-T segment elevation. The results do not suggest a simple quantitative relationship between epicardial S-T segment elevation and myocardial blood flow following acute coronary artery occlusion. (+info)
Non-invasive quantification of liver perfusion with dynamic computed tomography and a dual-input one-compartmental model. (2/12)Various liver diseases lead to significant alterations of the hepatic microcirculation. Therefore, quantification of hepatic perfusion has the potential to improve the assessment and management of liver diseases. Most methods used to quantify liver perfusion are invasive or controversial. This paper describes and validates a non-invasive method for the quantification of liver perfusion using computed tomography (CT). Dynamic single-section CT of the liver was performed after intravenous bolus administration of a low-molecular-mass iodinated contrast agent. Hepatic, aortic and portal-venous time-density curves were fitted with a dual-input one-compartmental model to calculate liver perfusion. Validation studies consisted of simultaneous measurements of hepatic perfusion with CT and with radiolabelled microspheres in rabbits at rest and after adenosine infusion. The feasibility and reproducibility of the CT method in humans was assessed by three observers in 10 patients without liver disease. In rabbits, significant correlations were observed between perfusion measurements obtained with CT and with microspheres (r=0.92 for total liver perfusion, r=0.81 for arterial perfusion and r=0.85 for portal perfusion). In patients, total liver plasma perfusion measured with CT was 112+/-28 ml.min(-1).100 ml(-1), arterial plasma perfusion was 18+/-12 ml.min(-1).100 ml(-1) and portal plasma perfusion was 93+/-31 ml.min(-1).100 ml(-1). The measurements obtained by the three observers were not significantly different from each other (P>0.1). Our results indicate that dynamic CT combined with a dual-input one-compartmental model provides a valid and reliable method for the non-invasive quantification of perfusion in the normal liver. (+info)
Lung albumin accumulation is spatially heterogeneous but not correlated with regional pulmonary perfusion. (3/12)The contribution of pulmonary perfusion heterogeneity to the development of regional differences in lung injury and edema is unknown. To test whether regional differences in pulmonary perfusion are associated with regional differences in microvascular function during lung injury, pigs were mechanically ventilated in the prone position and infused with endotoxin (Escherichia coli 055:B5, 0.15 microg. kg(-1). h(-1); n = 8) or saline (n = 4) for 4 h. Extravascular albumin accumulation and perfusion were measured in multiple approximately 0.7-ml lung regions by injecting pigs with radiolabeled albumin and radioactive microspheres, respectively. Extravascular albumin accumulation was spatially heterogeneous but not correlated with regional perfusion. Extravascular albumin accumulation was greater in dorsal than ventral regions, and regions with similar albumin accumulation were spatially clustered. This spatial organization was less evident in endotoxemic than control pigs. We conclude that there are regional differences in lung albumin accumulation that are spatially organized but not mediated by regional differences in pulmonary perfusion. We speculate that regional differences in microvascular pressure or endothelial function may account for the observed distribution of extravascular albumin accumulation. (+info)
Pulmonary neoplasms in rats that inhaled cerium-144 dioxide. (4/12)The lung neoplasms induced in rats by inhaled, internally deposited 144CeO2 were described and classified using histologic criteria. F344 rats were exposed once or repeatedly by inhalation to 144CeO2 and observed for their life span. There was significant life shortening only in those rats with the highest radiation doses. In these rats, there was a high percentage of squamous cell carcinomas of the lung, as well as much lower percentages of adenocarcinomas of the lung, hemangiosarcomas of the lung, and pleural mesotheliomas. At lower doses, adenocarcinomas were the most predominant tumor. These adenocarcinomas were subdivided based on their histologic pattern: alveolar, papillary, tubular, or undifferentiated. Neither the mode of exposure (single or repeated) nor the sex of the rat influenced the lung tumor incidence or tumor type. The lung neoplasms induced by this beta-emitting radionuclide are similar in nature to those induced by alpha-emitting radionuclides deposited in the lung in rats. However, the radiation-induced squamous cell carcinomas of the lung differ from those induced by heavy particle loads of nonradioactive compounds. The radiation-induced squamous cell carcinomas occur in higher incidence and have a more malignant behavior than those induced by heavy particle loads. (+info)
Revascularisation of bone grafts in rats. (5/12)Revascularisation of syngeneic and allogeneic intramuscular bone grafts have been studied using radioactive microspheres to measure the ingrowth of blood vessels. New bone formation and resorption were measured by 85strontium uptake and by graft weight reduction. Revascularisation, and mineralisation rate were significantly higher in syngeneic grafts than in allogeneic grafts at two, three and six weeks after implantation. The syngeneic grafts lost weight faster indicating that the allogeneic grafts resorbed more slowly. The ingrowth of new vessels is impaired in allogeneic bone, and this probably inhibits the rate of bone formation and resorption of the grafts. (+info)
Distribution and Translocation of 141Ce (III) in Horseradish. (6/12)BACKGROUND AND AIMS: Rare earth elements (REEs) are used in agriculture and a large amount of them contaminate the environment and enter foods. The distribution and translocation of (141)Ce (III) in horseradish was investigated in order to help understand the biochemical behaviour and toxic mechanism of REEs in plants. METHODS: The distribution and translocation of (141)Ce (III) in horseradish were investigated using autoradiography, liquid scintillation counting (LSC) and electron microscopic autoradiography (EMARG) techniques. The contents of (141)Ce (III) and nutrient elements were analysed using an inductively coupled plasma-atomic emission spectrometer (ICP-AES). RESULTS: The results from autoradiography and LSC indicated that (141)Ce (III) could be absorbed by horseradish and transferred from the leaf to the leaf-stalk and then to the root. The content of (141)Ce (III) in different parts of horseradish was as follows: root > leaf-stalk > leaf. The uptake rates of (141)Ce (III) in horseradish changed with the different organs and time. The content of (141)Ce (III) in developing leaves was greater than that in mature leaves. The results from EMARG indicated that (141)Ce (III) could penetrate through the cell membrane and enter the mesophyll cells, being present in both extra- and intra-cellular deposits. The contents of macronutrients in horseradish were decreased by (141)Ce (III) treatment. CONCLUSIONS: (141)Ce (III) can be absorbed and transferred between organs of horseradish with time, and the distribution was found to be different at different growth stages. (141)Ce (III) can enter the mesophyll cells via apoplast and symplast channels or via plasmodesmata. (141)Ce (III) can disturb the metabolism of macronutrients in horseradish. (+info)
Intestinal circulation during inhalation anesthesia. (7/12)This study was designed to evaluate the influence of inhalational agents on the intestinal circulation in an isolated loop preparation. Sixty dogs were studied, using three intestinal segments from each dog. Selected intestinal segments were pumped with aortic blood at a constant pressure of 100 mmHg. A mixture of 86Rb and 9-microns spheres labeled with 141Ce was injected into the arterial cannula supplying the intestinal loop, while mesenteric venous blood was collected for activity counting. A very strong and significant correlation was found between rubidium clearance and microsphere entrapment (r = 0.97, P less than 0.0001), suggesting that the shunting of 9-microns spheres through the intestines reflects the arteriovenous shunting of blood. Nitrous oxide anesthesia was accompanied by a higher vascular resistance (VR), lower flow (F), rubidium clearance (Cl-Rb), and microspheres entrapment (Cl-Sph) than pentobarbital anesthesia, indicating that the vascular bed in the intestinal segment was constricted and flow (total and nutritive) decreased. Halothane, enflurane, and isoflurane anesthesia were accompanied by a much lower arteriovenous oxygen content difference (AVDO2) and oxygen uptake than pentobarbital or nitrous oxide. Compared with pentobarbital, enflurane anesthesia was not accompanied by marked differences in VR, F, Cl-Rb, and Cl-Sph; halothane at 2 MAC decreased VR and increased F and Cl-Rb while isoflurane increased VR and decreased F. alpha-Adrenoceptor blockade with phentolamine (1 mg . kg-1) abolished isoflurane-induced vasoconstriction, suggesting that the increase in VR was mediated via circulating catecholamines.(ABSTRACT TRUNCATED AT 250 WORDS) (+info)
Total cerebral ischemia: a new model system for the study of post-cardiac arrest brain damage. (8/12)The pathophysiology of post-cardiac arrest brain damage is not well understood. Many of the model systems presently used to study global ischemia have serious limitations. A new model system for total cerebral ischemia (TCI), using aortic and inferior vena caval occlusion balloons, is described. This model system produces verifiable TCI and avoids surgical invasion of the thorax or the use of vasoactive drugs. It does not impede cerebral venous return and protects the cardiopulmonary system from damage. This model system can be used to study the efficacy of various therapeutic interventions following a standardized CNS global ischemic insult. (+info)
Cerium radioisotopes are radioactive isotopes of the element cerium that are used in various medical applications. These isotopes are typically produced by bombarding cerium targets with high-energy particles, such as protons or neutrons, in a nuclear reactor or particle accelerator. Cerium radioisotopes have a variety of uses in medicine, including: 1. Diagnostic imaging: Some cerium radioisotopes, such as cerium-144, are used as tracers in diagnostic imaging studies. These isotopes can be attached to molecules that are specific to certain organs or tissues in the body, allowing doctors to visualize the distribution of the tracer and diagnose various medical conditions. 2. Radiation therapy: Cerium radioisotopes can also be used in radiation therapy to treat cancer. For example, cerium-144 has been used in the treatment of bone metastases, a condition in which cancer has spread to the bones. 3. Nuclear medicine: Cerium radioisotopes can be used in nuclear medicine to treat a variety of conditions, including hyperthyroidism, thyroid cancer, and certain types of bone disease. These isotopes can be administered to the body in the form of a radioactive pill or injection, and they work by emitting radiation that destroys cancer cells or slows down the overactivity of certain organs. Overall, cerium radioisotopes play an important role in medical imaging and treatment, and they are widely used in hospitals and clinics around the world.
Cerium is a chemical element with the symbol Ce and atomic number 58. It is a soft, silvery-white metal that is rarely found in its pure form in nature. In the medical field, cerium is not commonly used as a treatment or medication. However, some studies have suggested that cerium may have potential therapeutic applications in the treatment of certain conditions, such as diabetes and cardiovascular disease. For example, cerium has been shown to have antioxidant properties and may help to reduce inflammation and oxidative stress in the body. However, more research is needed to fully understand the potential benefits and risks of using cerium in medicine.
Radioisotopes are isotopes of an element that emit radiation, such as alpha particles, beta particles, or gamma rays. In the medical field, radioisotopes are used in a variety of diagnostic and therapeutic applications. In diagnostic imaging, radioisotopes are used to create images of the body's internal structures. For example, a radioisotope such as technetium-99m can be injected into the bloodstream and then detected by a gamma camera to create an image of the heart, lungs, or other organs. This type of imaging is commonly used to diagnose conditions such as cancer, heart disease, and bone disorders. Radioisotopes are also used in therapeutic applications, such as radiation therapy for cancer. In this treatment, a radioisotope is introduced into the body, usually by injection or inhalation, and then targeted to a specific area of the body where it emits radiation that destroys cancer cells. Radioisotopes are also used in targeted radionuclide therapy, where a radioisotope is attached to a molecule that specifically targets cancer cells, allowing for more precise delivery of radiation. Overall, radioisotopes play a critical role in medical imaging and therapy, allowing for the diagnosis and treatment of a wide range of conditions.
Zinc radioisotopes are radioactive isotopes of the element zinc that are used in medical applications. These isotopes are typically produced by bombarding zinc targets with high-energy particles, such as protons or neutrons, in a nuclear reactor or particle accelerator. There are several different zinc radioisotopes that are used in medicine, including: * 67Zn: This isotope is used in positron emission tomography (PET) scans to image the brain and other organs. It is taken up by cells in the body and emits positrons, which can be detected by a PET scanner to create detailed images of the tissue. * 64Zn: This isotope is used in nuclear medicine to diagnose and treat certain types of cancer. It is taken up by cancer cells and can be used to image the tumor or to deliver radiation therapy to the cancer cells. * 70Zn: This isotope is used in research to study the metabolism and function of zinc in the body. It can be administered to animals or humans and then monitored to see how the zinc is distributed and used in the body. Zinc radioisotopes are typically administered to patients through injection or inhalation, and the amount of radiation exposure is carefully controlled to minimize any potential risks. They are an important tool in medical imaging and cancer treatment, and are used by healthcare professionals around the world.
Cerium isotopes are radioactive forms of the element cerium that are used in the medical field for various diagnostic and therapeutic purposes. Cerium-144 is a synthetic radioisotope that is used in nuclear medicine for imaging bone and soft tissue. It is produced by bombarding a target with high-energy protons, and is then used in diagnostic procedures such as bone scans to detect bone metastases, fractures, and other bone abnormalities. Cerium-144 is also used in radiation therapy for the treatment of certain types of cancer, such as prostate cancer. It is administered as a radioactive implant in the prostate gland, where it emits low-energy beta particles that destroy cancer cells while minimizing damage to surrounding healthy tissue. Cerium-144 has several advantages over other radioisotopes used in nuclear medicine, including a relatively long half-life of 182 days, low toxicity, and low energy emissions that minimize radiation exposure to patients and medical staff.
In the medical field, "Metals, Rare Earth" typically refers to a group of elements that are commonly used in medical devices and implants. These metals include titanium, stainless steel, cobalt-chromium alloys, and tantalum, among others. Rare earth metals, such as neodymium and samarium, are also used in some medical devices, such as MRI machines and dental implants. These metals are chosen for their biocompatibility, strength, and durability. They are often used in orthopedic implants, such as hip and knee replacements, dental implants, and spinal implants, as well as in cardiovascular devices, such as stents and pacemakers. However, it is important to note that some metals, such as nickel and cobalt, can cause allergic reactions in some patients. Therefore, medical professionals must carefully consider the patient's medical history and potential allergies before selecting a metal for a medical device or implant.
Auranofin is a medication that is used to treat rheumatoid arthritis. It is a gold-containing compound that works by reducing inflammation and slowing the progression of joint damage. Auranofin is usually taken orally in the form of a tablet. It is also sometimes used to treat psoriasis, a skin condition that causes red, scaly patches on the skin. Auranofin is generally well-tolerated, but it can cause side effects such as nausea, diarrhea, and an increased risk of infection. It is important to take Auranofin exactly as prescribed by your doctor, and to let your doctor know if you experience any side effects while taking this medication.
Plutonium is a radioactive element that is not naturally occurring in the environment. It is a synthetic element that is produced in nuclear reactors and is used as a fuel in nuclear weapons and as a component in nuclear power plants. In the medical field, plutonium has been studied for its potential use in cancer treatment. It has been shown to be effective in killing cancer cells, but it is also highly toxic and can cause serious health problems if not handled properly. As a result, the use of plutonium in medicine is limited and is only done in specialized research settings under strict safety protocols.
In the medical field, radioactive pollutants refer to any substances that contain radioactive isotopes and are present in the environment at levels that may pose a risk to human health. These pollutants can come from a variety of sources, including nuclear power plants, medical facilities, and the natural decay of radioactive elements in the earth. Radioactive pollutants can be inhaled or ingested, and can cause a range of health problems, including cancer, genetic mutations, and damage to the immune system. Exposure to high levels of radioactive pollutants can be particularly dangerous, as it can lead to acute radiation sickness and death. In medical settings, radioactive pollutants may be used for diagnostic and therapeutic purposes, such as in nuclear medicine and radiation therapy. However, proper handling and disposal of these substances are essential to prevent accidental exposure and minimize the risk of harm to patients and medical staff.
Americium is a radioactive element that is not commonly used in the medical field. It is a synthetic element with the atomic number 95 and the symbol Am. Americium has a half-life of about 432 years, which means that it takes that amount of time for half of the atoms of the element to decay into other elements. There are a few potential medical applications of americium, but they are not widely used. One possible use is in the treatment of certain types of cancer. Americium-241, a radioactive isotope of americium, has been used in some experimental cancer treatments, although it has not been approved for general use. Another potential use of americium in medicine is as a source of radiation for imaging studies. However, this use is also not widely used, and other types of radiation, such as X-rays and gamma rays, are more commonly used for imaging in the medical field.
Actinoid Series Elements are a group of elements in the periodic table that are located in the f-block, between actinium and lawrencium. These elements are highly radioactive and have unique chemical and physical properties. They are not commonly used in the medical field, but some of them have potential applications in nuclear medicine and radiation therapy. For example, actinium-225 is a promising isotope for targeted alpha therapy, a type of cancer treatment that uses alpha particles to destroy cancer cells. Thorium-227 is another actinoid isotope that is being studied for its potential use in cancer treatment.
Isotopes of cerium
Systems for Nuclear Auxiliary Power
Bioremediation of radioactive waste
List of MeSH codes (D01)
Fission products (by element)
Isotopes of praseodymium
Prices of chemical elements
Nuclear fission product
Radionuclide identification device
Ligand binding assay
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Pesquisa | Prevenção e Controle de Câncer
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Standardization of radioactivity|INIS
The EPA National Library Catalog | EPA National Library Network | US EPA
National Ambulatory Medical Care Survey, 1993
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Elements, Radioactive | Profiles RNS
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Picture of Neutron Poisons - Energy From Thorium
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Physicochemical Problems of Mineral Processing - Topic Properties of mineral materials
- In this study, an effective and efficient separation method for separating praseodymium from cerium was designed, optimized, and successfully implemented. (nstri.ir)
- Cerium, lanthanum, neodymium, and praseodymium, commonly in the form of a mixed oxide known as mischmetal, are used in steel making to remove impurities and in the production of special alloys. (knowinsiders.com)
- In 1938, during a nuclear experiment conducted at Ohio State University , a few radioactive nuclides were produced that certainly were not radioisotopes of neodymium or samarium, but there was a lack of chemical proof that element 61 was produced, and the discovery was not generally recognized. (wikipedia.org)
- Cr-50 is used for the production of the radioisotope Cr-51 which is used for measuring blood volume and red blood cell survival. (webelements.com)
- Li-7 is also used for the production of the medical research radioisotope Be-7. (shef.ac.uk)
- Li-6 can also be used for the production of the radioisotope H-3, which is used in biochemistry research. (shef.ac.uk)
- In nature, lanthanum mostly exists in combination with cerium. (periodic-table.com)
- K are found in all potassium, and it is the most common radioisotope in the human body. (wiki2.org)