Evaluation of cellular toxicity of three denture base acrylic resins.

OBJECTIVE: This study aimed to evaluate the cellular toxicity of two newly-released acrylic resins (Futura Gen and GC Reline Hard) in comparison with the conventional heat-cure resin (Meliodent). MATERIALS AND METHODS: Sample discs from each acrylic resin were placed in 24-well culture plates along with L929 mouse fibroblast cell line. A mixture of the RPMI 1640 medium, antibiotics and 10% FBS was added to the plates and the specimens were incubated in a CO(2) incubator. The amount of light absorption by each plate was determined after 1 hour, 24 hours and 1 week by the MTT assay and ELISA. The cytotoxic effect of the resins was compared among groups using the two-way ANOVA and further paired comparison was performed using the post-hoc Tukey's test. RESULTS: After 1 hour, Futura Gen displayed a significantly lower level of light absorption in comparison with Meliodent (P=0.03). After 24 hours, GC Reline Hard rendered a significantly lower level of light absorption compared to Meliodent (P=0.02). After one-week of incubation, the mean absorption rates for GC Reline Hard, Meliodent and Futura Gen were relatively similar (P>0.05). The lowest and highest level of cytotoxicity among all resins were observed after one week and 1 hour of immersion in water, respectively. CONCLUSION: All the tested resins induced some degree of cytotoxicity. Cytotoxicity of Futura Gen, GC Reline Hard and Meliodent resins failed to show any significant reduction from 24 hours to one week. Thus, it is recommended to immerse the dentures in water for 24 hours prior to delivery to the patient.

Argentine intercomparison programme for personal dosimetry.

An Intercomparison Programme is being carried out in Argentina for individual monitoring services. The programme was designed to test, on a voluntary basis, the performance of the laboratories that provide individual monitoring services for X and gamma radiation fields in the range from low-level dose up to 100 mSv. Irradiations were performed in full accordance with ISO 4037-3 recommendations by the Regional Reference Centre for Dosimetry (CRRD), belonging to Atomic Energy Commission (CNEA) and the Physical Dosimetry Laboratory of the Nuclear Regulatory Authority (ARN). At the same time, several items have been asked to each participant pertaining to the action range, the detectors' characteristics, the laboratory procedures, the existence of an algorithm and its use for the dosemeter evaluation. In this study the evolution of the laboratories' performance throughout the programme, based on ISO 14146 acceptance criteria, is shown.

Grazing affects essential oil compositions of Artemisia sieberi Besser.

This study was conducted in order to study the effect of grazing on quality and quantity of Artemisia sieberi essential oil in Kerman province of Iran. Vegetation sites of Artemisia sieberi under three grazing intensity (heavy, moderate and non-grazed) with the same ecological conditions were selected based on distance of water resource and nomad tent in Khabre National Park and near rangelands. Within each sits, two individual plants sampled at random in full flowering stage. The oils were obtained by hydrodistillation of air-dried samples and were analyzed by GC-MS. The main constituents of oils were as follows: non-grazed site; 1,8cineol (29.9%), myrcene (14.1%), moderate grazed site; myrcene (15.9%), 1,8cineol (15.1%), Eudesm-7(11)-en-4-ol (11.1%) and heavy grazed site; 4-tepinyl acetate (23.3%), davanone (21.9%), p-cymene (19%).

Results of the regional intercomparison exercise for the determination of operational quantity HP(10) in Latin America.

Several intercomparison exercises were organised by the International Atomic Energy Agency (IAEA) on the determination of operational quantities at the regional or interregional basis. In the Latin American region an intercomparison for the determination of the operational quantity Hp(10) was completed mid-2004, as a follow-up to previous exercises carried out during the 1990s. Eighteen individual external monitoring services from nineteen Member States participated in the first phase. The second phase grouped 15 services that had participated in the first phase. Dosemeter irradiations in photon beams were done by four Secondary Standard Dosimetry Laboratories (SSDLs) of the region. The preparation of this exercises involved an audit by the IAEA SSDL, where reference irradiations were provided to all participants for verification of their systems. During the first phase (2002-2003) only 9 out of 18 services met the performance requirements for such monitoring services. Necessary corrective actions and procedure verification were implemented. During the second phase (2004) 11 out of 15 services fulfilled the performance criteria. This intercomparison shows that there has been improvement in the second phase and most participants demonstrated a satisfactory performance of the quantity tested.

ESR/Alanine gamma-dosimetry in the 10-30 Gy range.

We report Alanine Dosimeter preparation, procedures for using the ESR/Dosimetry method, and the resulting calibration curve for gamma-irradiation in the range from 10-30 Gy. We use calibration curve to measure the irradiation dose in gamma-irradiation of human blood, as required in Blood Transfusion Therapy. The ESR/Alanine results are compared against those obtained using the thermoluminescent dosimetry (TLD) method.

Comparative performance of the enzyme-linked immunosorbent assay (ELISA) and conventional assays in the diagnosis of bovine brucellosis in Argentina.

The FAO/IAEA enzyme-linked immunosorbent assay (ELISA) kit for the diagnosis of bovine brucellosis was compared in Argentina with two screening tests, the Rose Bengal (RB) and the buffered plate antigen (BPA) agglutination tests and with two confirmatory tests, the 2-mercaptoethanol (2-ME) agglutination and the complement fixation (CF) tests. In the testing of Brucella abortus Strain 19 (S19) vaccinated cattle from Brucella-free dairy herds, the diagnostic specificity estimate of the ELISA (99.7%) was shown to be comparable to the RB (99.7%), 2-ME (99.8%) and CF (99.9%) and greater than the BPA (90.6%). In the testing of S19 vaccinated cattle from infected herds, the sensitivity estimates of the BPA (99.5%, 99.6% and 98.6% respectively) relative to CF,2-ME and ELISA positive reactors were comparable and high. The relative sensitivity estimates of the RB (86.3%, 81.4% and 79.1%) in the same comparison were disparate and lower. The ELISA demonstrated the highest relative sensitivity estimates (97.1% and 95.2% respectively) in a three-way comparison between ELISA, CF and 2-ME positive reactors from these herds. Relative to BPA positive reactors from the same infected herds, the sensitivity estimate of the ELISA (57.0%) was comparable to the 2-ME (56.2%) and higher than the CF (51.8%). These results would suggest that the overall diagnostic specificity and sensitivity of the ELISA test is comparable, if not superior, to the tests used to confirm BPA positive reactor status.