Improved procedures of Sc(OH)3 precipitation and UTEVA extraction for 44Sc separation.

BACKGROUND: 44Sc is becoming attractive as a PET radionuclide due to its decay characteristics. It can be produced from 44Ca present in natural calcium with 2.08% abundance. MATERIALS AND METHODS: The targets were mostly prepared from natural CaCO3 or metallic calcium in the form of pellets. After irradiation they were dissolved in 3 M hydrochloric acid and 44Sc was separated from excess of calcium by precipitation of scandium hydroxide using ammonia. Alternatively, targets were dissolved in 11 M hydrochloric acid and 44Sc was separated by extraction chromatography on UTEVA resin. As the next step, in both processes 44Sc was further purified on a cation exchange resin. Initially, the separation procedures were developed with 46Sc as a tracer. Gamma spectrometry with a high purity germanium detector was used to determine the separation efficiency. Finally, the CaCO3 pellet with 99.2% enrichment in 44Ca was activated with protons via 44Ca(p,n)44Sc nuclear reaction. RESULTS: Altogether twenty two irradiations and separations were performed. The working procedures were developed and the quality of separated 44Sc solution was confirmed by radiolabeling of DOTATATE. The chemical purity of the product was sufficient for preclinical experiments. At the end of around 1 hour proton beam irradiation of CaCO3 pellet with 99.2% enrichment in 44Ca the obtained radioactivity of 44Sc was more than 4.8 GBq. CONCLUSION: 44Sc can be produced inexpensively with adequate yields and radionuclidic purity via 44Ca(p,n)44Sc nuclear reaction in small cyclotrons. The recovery yield in both investigated separation methods was comparable and amounted above 90%. The obtained 44Sc was pure in terms of radionuclide and chemical purity, as shown by the results of peptide radiolabeling.

Reported concepts for the treatment modalities and pain management of temporomandibular disorders.

BACKGROUND: Pain related to temporomandibular disorders (TMD) is a common problem in modern societies. The aim of the article is to present the concepts of TMD pain clinical management. METHODS: A survey was performed using the PubMed, SCOPUS and CINAHL databases for documents published between 1994 and 2014. The following search keywords were selected using MeSH terms of the National Library of Medicine in combination: TMD pain, TMD, TMJ, TMJ disorders, occlusal splint, TMD physiotherapy, TMJ rheumatoid disorders and TMJ surgery. Original articles and review papers which presented the clinical relevance and practical validity regarding the possibility of application in TMD management have been included. Authors have excluded articles without outstanding practical aspect and evidence-based background. A first selection was carried out by reviewing titles and abstracts of all articles found according to the criteria. After that the full texts of potentially suitable articles were assessed. In line with these criteria, among 11467 results the writers have included 66 papers. RESULTS: The most commonly reported conservative treatments are massage therapy and individually fabricated occlusal splints. In addition to massage, other popular methods include manual therapy and taping, warming/cooling of aching joints, and light and laser therapy. Drugs are also commonly used. In the most severe cases of the temporomandibular joint degeneration, surgical restoration of the joint is sometimes applied. CONCLUSIONS: The authors concluded that conservative treatment including counselling, exercises, occlusal splint therapy, massage, manual therapy and others should be considered as a first choice therapy for TMD pain because of their low risk of side effects. In the case of severe acute pain or chronic pain resulting from serious disorders, inflammation and/or degeneration pharmacotherapy, minimally invasive and invasive procedures should be considered.