Use Of Radioactive Substances Research Articles

Assessment of Area Radiation Dose for the National Cyclotron and PET Centre at Chulabhorn Hospital in Thailand.

The National Cyclotron and PET Centre at Chulabhorn Hospital offers nuclear medicine diagnostic services using state-of-the-art digital PET/CT and PET/MRI machines as well as other related devices. Additionally, the center plays a vital role by having a cyclotron to produce radiopharmaceuticals, which are used both in-house and in other hospitals throughout the country. Despite the center's strict adherence to international standards regarding the use of radioactive substances in patients, there remains a potential risk of radiation exposure for operators, workers, and the public due to radioactive contamination and emissions from unsealed sources. Hence, it is imperative to assess and continuously monitor radiation levels in the work area to ensure the utmost level of safety for personnel. Methods: This study used optically stimulated luminescence dosimeters to measure radiation levels in 17 areas, consisting of 9 controlled and 8 supervised areas. Over a 3-mo period, the average monthly radiation dose was recorded for each location. Results: The PET/CT room registered the highest radiation dose within the controlled area, with a monthly average of 1.81 ± 0.29 mSv, equivalent to an annual dose of 21.72 mSv. This higher dose can be attributed to the significant number of patients served in this room. In supervised areas, the nursing counter located between the examination room and the patient waiting area exhibited the highest radiation exposure. The average monthly dose measured at this location was 0.085 ± 0.019 mSv, resulting in an annual dose of 1.015 mSv. Conclusion: The evaluation of radiation dose in controlled and supervised areas indicated that the overall radiation level remains within the prescribed limits. However, the slight excess that was observed at the nursing counter indicates the need for improvement to ensure compliance with the as-low-as-reasonably-achievable principle. Continuous monitoring of radiation levels should be conducted annually to maintain safety standards and minimize the risk that workers and the general public will be exposed to radioactivity.

Review paper on Radioactive Wastes and its Management

The waste that is left over after the use of radioactive materials in atomic reactors or at some point after the progress of atomic weapons is known as radioactive waste. Since the use of radioactive substances has been completed on a large scale in recent years, resulting in the creation of a big amount of radioactive waste, radioactive material management has become an important stage in dealing with it. Even if not correctly implemented, light from radioactive material will cause problems for humans and the climate. The peer-review paper discusses a well-known assessment of globally nuclear waste research. The cutting-edge evaluation includes studies on protection tests, decommissioning and disinfection of nuclear power plants, fusion power plants, and haulage. Furthermore, the evaluation emphasizes radioactive wastewater remediation, its management and final disposal alternatives for consumed petroleum and waste materials, by keeping in mind its effects on ecology due to radio radioactive isotope mobility in the ecology.

РОСІЯ “РАННЬОГО ПУТІНАˮ В ПОШУКАХ НОВОЇ НАЦІОНАЛЬНОЇ ІДЕНТИЧНОСТІ: МОДЕРНА ІМПЕРСЬКА ІДЕОЛОГІЯ В ТІНІ “ГУМАНІТАРНОГОˮ “РУСЬКОГО МИРУˮ

At the beginning of the XXI century the leadership of the Kremlin significantly strengthened control over the processes in the Russian state, achieved certain successes in the implementation of integration projects in the post-Soviet space. To increase the geopolitical weight of the Russian Federation and further strengthen its position on the territory of the so-called “near abroadˮ, Kremlin political technologists developed a new imperial ideology. Ivan Ilyin, a critic of the Bolsheviks and a supporter of monarchism and fascism, acted as an ideological guide for the Russian ruling elite. A practical manifestation of the new ideological approaches was the introduction of the “Day of People’s Unityˮ associated with the traditions of tsarist Russia, which essentially replaced the celebration of the so called “Great October Socialist Revolutionˮ. In the same vein, we can consider the launch of the action called “Saint George's ribbonˮ, which is a kind of attempt to combine the legacy of the Romanovs with the pages of the history of the USSR convenient for the Kremlin. Criticizing the federal nature of the Soviet Union, the Kremlin at the same time actively used the victory of the USSR in World War II for its geopolitical purposes. To the greatest extent, this was manifested due to the active popularization of the myth of the “Great Victoryˮ and the hypertrophied celebration of “Victory Dayˮ − the so-called “Pobedobesieˮ. One of the important components of the new state ideology of the Russian Federation was the active use of the “besieged fortressˮ concept. Tough declarations of the leadership of Russia at that time were complemented by decisive steps. The use of radioactive substances on the territory of Great Britain to kill a former employee of the FSB, cyber-attacks on the governmental structure of a NATO and EU member – Estonia, a return to the Soviet practice of aviation combat duty, a missile strike on Georgian territory by a Russian aircraft demonstrated the readiness of official Moscow to raise the stakes in the framework of the struggle for the redistribution of geopolitical “chessboardˮ. The ideological project “Russian Worldˮ became the decoration for Russian imperialism and revanchism. During the second presidential term of Vladimir Putin, it was already possible to trace warming signals that unequivocally demonstrated that behind the “humanitarianˮ envelope of “Russian Worldˮ the aggressive foreign policy goals of the Russian leadership were hidden. The most openly imperial essence of the Putin regime in its early stages is reflected in the framework of the so-called “Russian doctrineˮ. This document included provisions on the messianic role of Russia, criticism of the Bolsheviks for the division of the USSR into republics, the postulate on the historical continuity of the Russian Federation from tsarist times, etc. In the context of outlining the foreign policy goals of the Russian Federation, the doctrine refers to the creation of a multipolar world, the non-recognition of the 1991 Belovezh Accords, and the beginning of the path that should lead to the “reunificationˮ of Russia with Belarus, Ukraine and Kazakhstan is declared.

RISK MANAGEMENT OF INDUSTRIAL RADIOGRAPHY PERSONNEL CERTIFICATION ACTIVITIES TO ENSURE WORKER SAFETY AND HEALTH

RISK MANAGEMENT of Industrial Radiography Personnel Certification Activities to Ensure Worker Safety and Health. The increasing use of radioactive substances and other radiation sources in the Indonesian industry for non-destructive testing lead to a rise in the need for radiographers. In carrying out certification activities, NQSC utilizes radioactive sources in the form of gamma rays from X-ray appliances. Therefore adequate risk management to ensure the safety and health of participants is needed. The risk management process carried out by PSMN uses the hierarchy principle at ISO 45001 and other preventive measures regulated in the IAEA Safety Guidelines, with the measures evaluated periodically using dose reading data. The dosage results on workers and examinees showed that the dose value is below the allowable value with a Dose Limit Value (NBD) of no more than 20 mSv per year. This means that the risk management measures guarantee worker safety and health in the certification activities of industrial radiography personnel in PSMN.

The use of radioactive substances in medicine - history and development prospects

Nuclear medicine (NM) is a medical specialty that uses radionuclides (radioactive tracers) and ionising radiation for diagnostic and therapeutic (theranostic) purposes. Nuclear medicine arose and developed at the intersection of physics, chemistry and clinical medicine. The radiation emitted by radioisotopes can consist of gamma-, beta- and alpha emission, or it's combination. Radioisotope of choice for medical purposes should have futher requirements: low radiotoxicity, suitable type of radiation, energy and half-life (several minutes to several hours and days), and also convenient detection of gamma ray radiation. The radionuclide is part of radiopharmaceutical (RP) and acts as its indicator. RP accumulates in morphological structures, becomes a carrier of coordinated information from patient to gamma camera or other equipment and reflects the dynamics of processes occurring in the examined organ. In 2021 NM celebrates its 80th anniversary. The trajectory of NM combines modern methods of radiotheranostics and applied genomic and post-genomic technologies.

Highlights of Radioisotope, Radiochemistry, and Radiotracer Development in Australia

Australia has a rich and long history in the nuclear science and technology sector. Nuclear medicine involves the use of radioactive substances and molecular imaging equipment to diagnose and treat diseases and is an ever-growing field around the globe. In fact, it is estimated that one in two Australians will require a nuclear medicine procedure during their lifetime. Progress by Australian scientists during the 21st century in radioisotope production, radiochemistry methodology, and radiotracer development for applications in nuclear medicine is reviewed. These developments will allow facile access to the next generation of nuclear medicines for diagnostic and therapeutic purposes.

Nanopore-Based, Label-Free, and Real-Time Monitoring Assay for DNA Methyltransferase Activity and Inhibition.

DNA methylation catalyzed by DNA methyltransferase plays an important role in many biological processes. However, conventional assays proposed for DNA methyltransferase activity are laborious and discontinuous. We have proposed a novel method for real-time monitoring of the activity and kinetics of Escherichia coli DNA adenine methyltransferase (Dam) using nanopore technique coupled with enzyme-linkage reactions. A double-stranded DNA probe AB having a recognition sequence 5'-GATC-3' for both Dam and MboI restriction endonuclease was prepared. Dam catalyzed the methylation of substrate probe AB, which blocked the cleavage reaction of MboI, while the absence of Dam resulted in cleavage of nonmethylated probe AB into four ssDNA fragments by MboI. When tested with nanopore, double-stranded methylated probe AB generated long-lived events, distinguished clearly from MboI-cleavage-mediated ssDNA fragments that generated only spikelike events. The proposed method has a detection limit of 0.03 U/mL for Dam in a short assay time of about 150 min. This sensing system is easy to perform, simple to design and circumvents the use of radioactive substances, resulting in efficient detection of the activity of Dam even in complex matrixes like human serum sample. Furthermore, it has the potential to screen Dam-targeted inhibitor drugs which may assist in the discovery of new anticancer medicines. This method is general and could be extended easily for monitoring activity of a wide variety of methyltransferases by coupling with their corresponding methylation-sensitive endonucleases.

ӨНДІРІСТІК АЙМАҚТАРДЫҢ РАДИАЦИЯЛЫҚ ФОНЫН ЗЕРТТЕУ

Because of the wide use of radioactive substances there is a threat of soil contamination with radionuclides.Sources of radiation – nuclear facilities, nuclear weapons testing, uranium mine waste. Potentialsources of radioactive contamination are accidents at nuclear installations. In the upper soil layer andconcentrate radioactive cesium and strontium, which enter the body of humans and animals.The accumulation of radionuclides in the environment in large quantities can lead to tragic situations.A large part of the radionuclides are in the soil, in its upper and lower layers, so their movementslargely depends on the types of soils, their granulometric composition and water-physical and agrochemical properties. The transfer speed depends on hydro-meteorological effects (wind speed andintensity of precipitation), topography, terrain, type of soil and plants and physico-chemical propertiesof the nuclides.Therefore it is necessary to carry out radiation monitoring of the environment.The article presents the results of a study of background radiation and the specific activity of the isotopecesium-137 near the industrial enterprises of Uralsk. The studies were conducted for each season ofthe year. The proposed pattern of change of the specific activity of the isotope cesium-137 in air, water,soil, plants nearby businesses.

Case Report: Unusual Radiation Risks in the Emergency Department –125I beads

The use of radioactive substances in medicine accounts for the largest radiation exposure to the population from non-natural sources worldwide. The use in healthcare confers many benefits, but inappropriate or unskilled use can result in health hazards and safety issues for both patients and healthcare workers. We present two cases of radiation safety issues related to patients presenting to our emergency department after receiving non-conventional brachytherapy in the form of radiation seeds being implanted in the abdominal wall. These were done for presumed treatment of metastatic cancer in another Asian country. We share our cases to all emergency department staff to heighten their alertness for potential exposure to radiation from patients with radionuclides.

Sensitive non-radioactive determination of aminotransferase stereospecificity for C-4′ hydrogen transfer on the coenzyme

A sensitive non-radioactive method for determination of the stereospecificity of the C-4′ hydrogen transfer on the coenzymes (pyridoxal phosphate, PLP; and pyridoxamine phosphate, PMP) of aminotransferases has been developed. Aminotransferase of unknown stereospecificity in its PLP form was incubated in 2 H 2 O with a substrate amino acid resulted in PMP labeled with deuterium at C-4′ in the pro -S or pro -R configuration according to the stereospecificity of the aminotransferase tested. The [4′- 2H]PMP was isolated from the enzyme protein and divided into two portions. The first portion was incubated in aqueous buffer with apo-aspartate aminotransferase (a reference si-face specific enzyme), and the other was incubated with apo-branched-chain amino acid aminotransferase (a reference re-face specific enzyme) in the presence of a substrate 2-oxo acid. The 2H at C-4′ is retained with the PLP if the aminotransferase in question transfers C-4′ hydrogen on the opposite face of the coenzyme compared with the reference aminotransferase, but the 2H is removed if the test and reference aminotransferases catalyze hydrogen transfer on the same face. PLP formed in the final reactions was analyzed by LC–MS/MS for the presence or absence of 2H. The method was highly sensitive that for the aminotransferase with ca. 50 kDa subunit molecular weight, only 2 mg of the enzyme was sufficient for the whole test. With this method, the use of radioactive substances could be avoided without compromising the sensitivity of the assay.

A Novel Continuous Breath Test Versus Scintigraphy for Gastric Emptying Rate Measurement

Gastric scintigraphy (GS) is considered the gold standard for gastric emptying rate (GER) measurement; however, it requires expensive equipment and special licensing for radioactive substances. To compare a new nonradioactive, real-time, continuous breath test (CBT) method with GS for the GER measurement. Simultaneous GER analysis by both GS and CBT was carried out on 8 dyspeptic patients and 6 healthy controls. After a 14 hour fast, participants ate a standard meal of 250 Kcal double labeled with 1 mCi of Tc-99m and 100 μg of C-13 labeled octanoic acid. The participants underwent simultaneous GS for 120 minutes on single-detector γ camera and CBT carried out by attaching the nasal cannula of the system (Oridion, BreathID, Israel), which automatically and continuously collected and analyzed breath samples with real time display. A linear fit model was used to calculate gastric empting half-time. A half-time of more than 100 minutes for GS and 80 minutes for CBT were considered pathologic. The GS and CBT were compared by κ test of agreement in normal/abnormal results. Good correlation was found for GER measurements between GS and the CBT methods with a linear correlation coefficient of R=0.74. The κ test indicated excellent agreement with value of 0.86 for the qualitative determination of pathologic and normal results. The novel CBT provides reliable and reasonably accurate data for on-line GER estimate, in a simple manner suitable for medical clinics or bedside setting, without the use of radioactive substances.

A Pervasive System for Nuclear Medicine Department

Pervasive Computing technologies can be successfully adopted in designing smart and enhanced healthcare services and applications. Within a typical healthcare institution, one particular facility which can greatly benefit from pervasive technologies is the Nuclear Medicine Department, where nuclear medicine diagnostic tests like PET scan and nuclear scintigraphy are routinely carried out involving the use of radioactive substances. This paper presents a pervasive healthcare system which is intended to support clinicians in handling nuclear medicine test sessions within an appropriate, safety-aware context. The proposed system also includes features to easily interoperate with heterogeneous software and databases already present in traditional hospitals. Its design lies on a methodology which integrates RFID and photoelectric sensor technologies. An experimental prototype has been implemented and tested showing the feasibility of the system in a real healthcare facility.

３．マイクロドーズ臨床試験の実践

Following the publication of the guidance information for clinical studies, it is increasingly important to create an environment conductive to the implementation of microdosing clinical trials. It is known that the accelerator mass spectrometry method using radiolabeled compounds is advantageous over liquid chromatograph/mass spectrometry/mass spectrometry method in detecting and determining Japanese-specific metabolites. However to date, no pharmacokinetic study using radiolabeled compounds has been conducted for drug development in Japan probably due to a resistance in the use of radioactive substances. It is important to demonstrate the safety of the administration of a small dose of radiolabeled compound. When a microdosing clinical trial is conducted as a first in a human trial in drug development, the principal investigator and the deliberators in the Institutional Review Board (Ethics Committee) should be cautious from both the scientific and ethical viewpoints.

Significance of terminal deoxynucleotidyl transferase in patients with acute leukemia and malignant lymphoma: results obtained by immunofluorescence assay (author's transl)

Deoxynucleotidyl transferase (TdT) is of diagnostic and therapeutic importance in acute leukaemia and malignant lymphoma. Previous methods for determining TdT activity by biochemical assay are complex and require the use of radioactive substances. There now is available a specific antibody for immunofluorescent demonstration of TdT. The two methods were compared on samples from 43 patients with leukemia or malignant lymphoma. There was very good agreement. High TdT activity was found in 12 of 14 patients with acute lymphatic leukemia and in one of two with acute undifferentiated leukaemia. TdT activity was absent with acute and chronic myeloid leukaemia, chronic lymphatic leukaemia and non-Hodgkin's lymphoma of low malignancy. Immunofluorescence assay, although its results are of similar significance to that obtained with the biochemical tests, is simpler to do. Furthermore, it can be done on normal bone-marrow smear or lymph-node preparations and can be correlated with the morphological findings.

Mobile PET in the UK: legislative, regulatory and cost-effectiveness considerations

Mobile PET/CT or mobile stand alone PET, is becoming more widely available throughout the developed world, allowing many small and medium-sized hospitals that do not have the scale or financial resources to purchase the static diagnostic equipment, to benefit from this imaging technology. Before embarking on such a service, a number of legislative, logistical and administrative issues have to be addressed to ensure that a mobile PET/CT service is run with optimal efficiency and safety and in compliance with the regulations governing the use of radioactive substances. Some of these issues are similar to those encountered in operating a mobile magnetic resonance imaging scanner but there are important differences owing to the use of both sealed and open radioactive sources. This article highlights the legislative, administrative and practical issues relevant to the UK and also discusses some of the practical issues that need to be addressed to ensure the operation of a safe and effective PET service.

An exercise to estimate differential gene expression in human cells

The expression of genes in cells of various tissue types varies considerably and is correlated with the function of a particular organ. The pattern of gene expression changes in diseased tissues, in response to therapy or infection and exposure to environmental mutagens, chemicals, ultraviolet light, and ionizing radiation. To better understand the disease at the molecular level, the alterations in gene expression can provide clues to identify the cellular pathways involved. There are a wide variety of techniques that have been developed to study differential gene expression. Most of these methodologies are technically challenging. We developed an exercise to examine and quantify differential gene expression based on reverse transcription-PCR. Our goal was to have this technique successfully performed by college level students. This technique is easy to perform and does not require the use of radioactive substances. We examined the ionizing radiation-induced changes in gene expression in human cells. After exposure to ionizing radiation, total RNA was isolated at 4, 8, 12, and 24 h. The RNA was converted to cDNA and subjected to PCR amplification using gene-specific primers and commercially available β-actin internal standards in a multiplex format. The differences in gene expression were quantified with freely available imaging software. This technique should have a wide application to investigate differential gene expression in a variety of organisms and under various experimental and treatment conditions.

Skin microcirculation in healthy subjects and patients with arteriosclerosis.

The concept to use the human skin microcirculation as a pharmacological in-vivo test system is old; however, methods developed in the 50s have been abandoned because of side effects and/or use of radioactive substances. We describe a newly developed minimally invasive method that allows in-vivo pharmacology in the human skin microcirculation injecting very low doses of a substance of drug without any systemic effects. The double injection technique (DIT) bears the potential to predict the effects of a drug and/or the vascular reactivity or dysfunction of other less accessible areas of the circulation (e.g. the myocardium). The DIT has been applied for studies in healthy volunteers and patients with atherosclerosis; the focus of interest was endothelial (dys-)function and the effect of exogenous vasoactive drugs. Using endothelin antagonists, we investigated the role of endogenous endothelin under physiological conditions and in atherosclerosis. The NO-synthase inhibitor L-NMMA has been applied to study the L-arginine-NO-pathway and the role of endothelial adrenoceptors. Ongoing studies with the DIT comparing coronary and skin microcirculation may help to develop minimally invasive methods to predict the effects of drugs and vascular function in the heart.

Formation of Nonextractable Soil Residues: A Stable Isotope Approach

Stable carbon isotopic measurements were employed to characterize the transformation of a 13C-labeled polycyclic aromatic hydrocarbon (PAH), anthracene, in a closed soil bioreactor system. The 13C-label was used to calculate a carbon mass balance including mineralization and the formation of nonextractable soil-bound residues. Similar results were obtained from 13C-labeled carbon and 14C-labeled carbon mass balance calculations for separate batch experiments with labeled anthracene. In concentration ranges typical for real PAH-contaminated sites, the sensitivity of the 13C tracer method meets the requirements of classical radiotracer experiments. Therefore, our balancing method based on stable isotope-labeled chemicals may supplement or substitute radiotracer experiments under many circumstances. One major advantage of using stable isotope-labeled tracers is the possible application in transformation studies where the use of radioactive substances is of environmental concern. The transformation of 13C-labeled PAH into nonextractable residues clearly depends on the metabolic activity of the soil microflora and occurs during an early phase of biodegradation. Successive contamination of the soil by anthracene leads to a progressive adaptation of the microflora to a complete mineralization of anthracene in the soil. The extent of residue formation is controlled by the capability of the microflora to degrade the contaminant. Results of long-term experiments indicate that nonextractable residues are relatively stable over time.

Strontium as a Tracer for Calcium in Biological and Clinical Research

The calcium ion is required for the operation of a number of physiological processes, such as bone and tooth formation, blood coagulation, nerve impulse transmission, and muscle contraction. At the cellular-biochemical level, the calcium ion participates in signal transduction and is a significant factor in cell replication and cell division. The ultimate source of this important element is the diet, and the proper absorption of calcium is required to meet body needs. Abnormal or inadequate calcium absorption is a contributing factor in certain disease states, including osteoporosis, vitamin D-deficiency rickets, vitamin D-dependent rickets types I and II, and chronic renal failure, to name a few. The continued study of calcium absorption and calcium metabolism in animals and humans is essential for further elucidation of basic mechanisms, for understanding of disease processes, and for assessment of the efficacy of therapeutic strategies. Importantly, the use of tracer methodologies in studies of calcium metabolism has provided valuable information not otherwise attainable. The radionuclides of calcium that have been widely used with considerable advantage as tracers in the study of calcium and bone metabolism are the beta-emitting Ca and the gamma-emitting Ca. However, the use of radioactive substances in basic and clinical research is dwindling because of the costs of radionuclides, the costs of disposal of radioactive wastes, and the justifiable reticence of giving potentially hazardous radionuclides to human subjects, particularly to the young and the pregnant. Stable isotopes of calcium are available that have been beneficially used in human and animal studies but here the disadvantages are the cost of the stable isotopes of calcium (Ca, Ca) and the more specialized equipment required for their analysis. For these and other reasons, researchers have turned to the use of strontium as a surrogate for calcium. The strontium and the calcium ions, members of the …

Chemical synovectomy vs. radioactive synovectomy for the treatment of chronic haemophilic synovitis: a prospective short-term study.

Between January 1992 and December 1994, a prospective study was performed in two centres comparing chemical synovectomy using repeated weekly injections (range, 1-17) of Rifampicin (Group R) vs. radioactive synovectomy using 1-2 injections of Yttrium-90 (Group Y). The study was performed on 38 joints in a total of 35 haemophilic patients suffering from chronic haemophilic synovitis unresponsive to 3 months of conservative treatment (substitution therapy with the deficient coagulation factor plus a rehabilitation protocol). Group R included 18 patients with an average age of 9 years, with an average follow-up time of 25 months. In Group R, 19 joints were treated: nine knees, four elbows and six ankles. Group Y included 17 patients with an average age of 18 years, with an average follow-up time of 23 months. In Group Y, 19 joints were treated: 14 knees, two elbows and three ankles. The joints were evaluated according to the frequency of bleeding episodes and the Pettersson radiographic score. On the basis of the radiographic scale at the time of the synoviortheses, the joints were categorized as stage I (0 points), stage II (1-2 points), stage III (3-7 points), stage IV (8-10 points) and stage V (11-13 points). The overall results showed that in Group R, bleeding decreased in 12 joints, remained the same in six and worsened in one. In Group Y, bleeding decreased in 11 joints, remained the same in seven and worsened in one. In both Groups, bleeding was controlled best if joints were in stages I and II. In stages III, IV and V, synoviorthesis should not be carried out in haemophilia because it is not effective. Use of radioactive substances in persons under the age of 9 years has been discouraged in the past and therefore only Rifampicin was used in this age group. However, in patients over 9 years of age, this study showed similar decrease of bleeding in both treatment groups. Taking into account the advantages and disadvantages of both agents, we suggest the use of Rifampicin in elbows and ankles but prefer Yttrium-90 for the knees.