Influence of Feeding and Organism Age on the Acute Toxicity of Sodium Bromide to Artemia salina

Bromide is a common ion found in freshwater and marine systems. Although normally at relatively low concentrations, higher levels may occur in point-released wastewaters as well as nonpoint runoff from agricultural or industrial locations where bromide compounds are used as biocides and disinfectants. In this study, the potential toxicity of NaBr in a saltwater environment was studied using the brine shrimp, Artemia salina. The confounding factors of organism age at test initiation and pre-test feeding were included in the test design. Survival of brine shrimp nauplii in several NaBr treatments up to 11,000 mg Br−/L (measured) was assessed after 24 h in both fed- and unfed-tests. In tests with unfed organisms, only the youngest (< 24 h old) nauplii had acceptable control survival (≥90%), while control survival for all of the tests with fed organisms (< 24 h old, < 48 h old, < 72 h old) was acceptable. There was also greater and more erratic mortality in the unfed tests. These data indicate feeding A. salina prior to initiating a short-term acute test improved performance. Not feeding the test organisms, especially in longer tests or when using > 24 h old organisms, may result in excessive control mortality and an invalid test. These studies show that, when healthy organisms are used in the toxicity tests, 11,000 mg/L of Br− (~ 14,200 mg/L NaBr) is not acutely toxic to Artemia salina.

Evaluation of early skin or laryngeal reaction at oral food challenge

Background: An oral food challenge (OFC) is required for diagnosing food allergies; however, uncertain reactions can impair the determination of when to stop the test. We aimed to determine the associations between immediately occurring mild allergic skin signs/laryngeal symptoms and positive OFC results. Methods: We retrospectively included children (aged 6 months to 15 years) who underwent open OFC for hen’s egg (HE), cow’s milk (CM), or wheat at a single centre between May 2012 and March 2020. Participants with mild skin signs or laryngeal symptoms at OFC initiation were classified as “skin” or “laryngeal” cases, respectively. Using logistic regression, the risk of positive OFC results, in a skin or laryngeal case, was assessed using univariate and multivariate analyses. Age, sex, total target dose, and serum levels of total and food-specific immunoglobulin E were used as covariates in prediction models. Results: In total, 2954, 1126, and 850 tests for HE, CM, and wheat, respectively, were included and comprised 115 (4%) and 25 (0.9%), 92 (9%) and 24 (2%), and 7 (1.3%) and 0 (0%) skin and laryngeal cases, respectively. Children with reactions to both HE and CM had a higher risk of a positive OFC than controls (odds ratio [95% confidence interval]: 4.6 [3.3–6.4], 2.9 [2.0–4.1] and 6.5 [3.0–10.9], 4.9 [2.2–10.9], respectively). Areas under the curves of prediction models ranged from 0.61 to 0.71. Conclusions: Uncertain reactions immediately after test initiation could not robustly predict OFC results, indicating the OFC could be continued under careful observation.

Practical implications of single-gene versus NGS testing in advanced NSCLC.

e23106 Background: Genetic testing to guide 1st-line treatment is recommended for advanced non-small cell lung cancer (aNSCLC), but is complicated by small biopsy specimens available to test increasing numbers of biomarkers. This study compared commercially-available genetic tests for aNSCLC and the investigational use Oncomine™ Dx Target Test next generation sequencing (NGS) assay. Methods: This retrospective analysis used data from a large commercial lab, which offered clinical single-gene tests (EGFR therascreen, ALK Vysis, BRAF cobas, laboratory developed tests [LDT] for ROS1, BRAF, KRAS, MET, RET, and FGFR1); and NGS LDT (Illumina NextSeq 500). The lab also conducted investigational use of Oncomine Dx Target Test assay (Ion Torrent PGM Dx) on archival tissue. Clinical test orders received September 2015 – October 2016 were included. Sample rejection, test initiation, success rates, slide consumption, testing time, and turnaround time (TAT) were assessed. Results: Clinically, 3,857 single-gene and 219 NGS LDT tests were ordered on 1,479 samples for 1,436 patients. A total of 169 Oncomine Dx Target Tests were conducted. Conclusions: Investigational use of Oncomine Dx Target Test at this laboratory showed higher rates of test initiation and successful completion while using less tissue compared to either single-gene testing for ≥4 biomarkers or NGS LDT. This early experience suggests Oncomine Dx Target Test may enable therapy selection with multiple biomarker testing on small tissue samples for more aNSCLC patients compared to current methods. [Table: see text]

Large-scale geomechanical model testing of an underground cavern group in a true three-dimensional (3-D) stress state

The stability of a large cavern group at great depth is discussed on the basis of large-scale three-dimensional (3-D) geomechanical model tests and numerical simulations. The model tests are described in detail. Improvements in the tests were made in terms of experimental techniques and advanced measurement methods. The model tests utilized active loading on six sides of a rock mass in a true 3-D stress state. During the model construction, precast blocks were fabricated and monitoring holes were defined prior to test initiation. Newly developed combination ball-sliding walls were installed on each of the major loading surfaces to reduce the friction induced by model deformation. A unique grouting and installation technique employing prestressed cables was adopted in the tests. A digital photogrammetric technique, displacement sensing bars using fiber Bragg grating (FBG) technology, and mini multipoint extensometers were developed for measuring deformation. Overloading tests were then conducted for different overburden depths, and 3-D numerical analyses were performed to simulate the testing procedures. Conclusions regarding the stability of the cavern group were developed based on a comparison between the experimental and numerical results.