The Association Between Race and Diagnostic Delay of Retinoblastoma in US Children

The Association Between Race and Diagnostic Delay of Retinoblastoma in US Children Alexander K. Black1, Amanda E. Kahn2, Roberto Warman3, Noël C. Barengo4 1 Florida International University Herbert Wertheim College of Medicine, [email protected], ORCID: 0000-0003-1688-5109 2 Florida International University Herbert Wertheim College of Medicine, [email protected], ORICD: 0000-0002-8045-4576 3 Florida International University Herbert Wertheim College of Medicine, [email protected]. 4 Florida International University Herbert Wertheim College of Medicine, [email protected], ORCID: 0000-0003-0660-3091 Objective: Explore associations between race and age at diagnosis of retinoblastoma in children in the United States between 1988-2018. Methods: An analytical non-concurrent cohort study was conducted using the Surveillance, Epidemiology, and End Results (SEER) database from 1988-2018. The cohort includes children ages 0-17 diagnosed with retinoblastoma. The exposure was race and the outcome was age at diagnosis. Primary diagnosis after two years old was considered diagnostic delay. Covariates include sex, rural-urban continuum, ethnicity, decade of diagnosis, and disease laterality. Unadjusted and adjusted logistic regression analysis were performed to calculate odds ratios (OR) and 95% confidence intervals (CI). Results: In total, 747 participants met inclusion criteria. By racial group, 70.15% of participants were white, 16.33% black, 10.98% Asian/Pacific Islander and 2.54% American Indian/Alaska native. By ethnicity, 84.34% were non-Hispanic. No statistically significant associations between racial or ethnic groups and age at diagnosis compared to the non-Hispanic white control group (black OR 0.92; 95% CI 0.58-1.54, Asian/Pacific Islander OR 1.15; 95% CI 0.50-19.95, American Indian/Alaska native OR 0.61; 95% CI 0.20-1.85, Hispanic OR 0.86; 95% CI 0.52 -1.41) were found. Females were significantly more likely to be diagnosed under age two compared to males (OR 0.62; 95% CI 0.44-0.88). Conclusion: While many variables affect development of retinoblastoma, this nationwide study of US children suggests that timely identification of retinoblastoma does not differ based on race or ethnicity. Keywords: retinoblastoma, race/ethnicity, epidemiolog

Thermal energy storage in a confined aquifer: Experimental results

This is the published version. Copyright 1979 American Geophysical UnionTo aid in testing the idea of storing thermal energy in aquifers, an experiment was performed by Auburn University in which 54,784 m3 of water was pumped from a shallow supply aquifer, heated to an average temperature of 55°C, and injected into a deeper confined aquifer where the ambient temperature was 20°C. After a storage period of 51 days, 55,345 m3 of water were produced from the confined aquifer. Throughout the experiment, which lasted approximately 6 months, groundwater temperatures were recorded at six depths in each of 10 observation wells, and hydraulic heads were recorded in five observation wells. In order to prevent errors due to thermal convection, most of the observation wells recording temperature had to be backfilled with sand. During the 41-day production period, the temperature of the produced water varied from 55° to 33°C, and 65% of the injected thermal energy was recovered. At no time was an appreciable amount of free thermal convection observed in the storage formation. The dominant heat dissipation mechanisms appeared to be hydrodynamic thermal dispersion and possible mixing of cold and hot water induced by clogging and unclogging of the injection-production well. On the basis of laboratory and field studies, it was concluded that clogging of the injection well, which constituted the major technical problem during the experiment, was caused by the freshwater-sensitive nature of the storage aquifer. Due to the relatively low concentration of cations in the supply water, clay particles would swell, disperse, and migrate until they became trapped in the relatively small pores connecting the larger pores. Surging the pump and back washing the injection well would dislodge the clogging particles and temporarily improve the storage formation permeability. The phenomenon seems largely independent of temperature because it was reproduced in the laboratory with unheated water. It may, however, depend on pore velocity. Future research should be directed toward procedures for selecting storage aquifers that will have minimal susceptibility to clogging and other geochemical problems. Procedures for overcoming such difficulties are needed also because clogging and related phenomena will be more the rule than the exception. Designing an aquifer thermal storage system for maximum energy recovery would involve selecting an appropriate aquifer, analyzing the effects of hydrodynamic thermal dispersion and thermal convection if it is predicted to occur, anticipating geochemical problems, designing the optimum supply-injection-production well configuration and injecting a sufficiently large volume of heated water to realize economies of scale related to increasing volume-surface area ratio

Expansion Thoracoplasty Affects Lung Growth and Morphology in a Rabbit Model: A Pilot Study

Background: Thoracic insufficiency syndrome represents a novel form of postnatal restrictive respiratory disease occurring in children with early-onset scoliosis and chest wall anomalies. Expansion thoracoplasty improves lung volumes in children with thoracic insufficiency syndrome; however, how it affects lung development is unknown. Questions/purposes: Using a rabbit model of thoracic insufficiency syndrome, we evaluated the effect of expansion thoracoplasty on the response of biologic mechanisms in the alveolar microstructure. Methods: Using archived material from a previous experiment, 10 4-week-old New Zealand rabbits were divided into three groups: normal (n = 3), disease (n = 3), and treated (n = 4). Left ribs four to eight were tethered in seven rabbits at age 5 weeks to induce hypoplasia of the left hemithorax (disease). At age 10 weeks, four of these rabbits were treated by expansion thoracoplasty (treated). At age 24 weeks, lungs were excised and processed. Alveolar density and parenchymal airspace were measured on histologic sections. Immunohistochemistry was performed for vascular endothelial growth factor receptor 2 (angiogenesis), KI-67 (cell proliferation), and RAM-11 (macrophages). Results: Alveolar walls were poorly perfused and airspace fraction was larger (emphysematous) in disease rabbits than normal or treated rabbits. Immunohistochemistry provided inconclusive evidence to support the concept that pulmonary hypoplasia is induced by thoracic insufficiency syndrome and controlled by expansion thoracoplasty. Conclusions: Treatment of thoracic insufficiency syndrome by expansion thoracoplasty may prevent emphysematous changes in the alveolar microstructure, thereby enhancing gas exchange