Publications by authors named "John Brockman"

Since 1968, the United States Transuranium and Uranium Registries (USTUR) has studied the biokinetics and tissue dosimetry of uranium and transuranium elements in nuclear workers. As part of the USTUR collaboration with the Million Person Study (MPS) of Low-Dose Health Effects, radiation dose to different parts of the human heart is being estimated for workers with documented intakes of 239Pu or 226Ra. The study may be expanded for workers with intakes of 238U and other radionuclides.

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Background And Objectives: Studies have indicated that cadmium (Cd) exposure is associated with neurotoxicity. However, data linking Cd exposure to cognitive impairment are sparse. We aimed to investigate the association between urinary Cd concentration and cognitive impairment in US adults.

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Environmental exposures such as cadmium might be contributing to the increasing incidence of pancreatic cancer. Few prospective studies have examined the association between trace elements and pancreatic ductal adenocarcinoma (PDAC). We conducted a nested case-control study in participants aged 55-74 years at baseline from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial cohort to examine the association between 12 trace elements measured in predignostic whole blood and PDAC.

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Purpose: There are several pathways by which zinc may be a modifiable factor to slow age-related cognitive decline. We investigated the associations between serum and dietary zinc and cognitive impairment in a longitudinal cohort.

Methods: We used data from the REasons for Geographic and Racial Differences in Stroke (REGARDS) Cohort (n = 30,239) and the REGARDS Trace Element Study (n = 2666).

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The levels of the SELENOF selenoprotein are dramatically reduced in prostate cancer compared to adjacent benign tissue and reducing SELENOF in prostate epithelial cells results in the acquisition of features of the transformed phenotype. It was hypothesized that the aberrant increase in the eiF4a3 translation factor, which has an established role in RNA splicing and the regulation of selenoprotein translation, contributes to the lower levels of SELENOF. Using the available databases, eIF4a3 messenger RNA (mRNA) levels are elevated in prostate cancer compared to normal tissue as is the hypomethylation of the corresponding gene.

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Lower back pain is one of the leading causes of disability, affecting 11.9% of the population worldwide and studies have shown that intervertebral disc degeneration is a common cause for chronic lower back pain. We have explored the combination of three components, viscoelastic collagen, genipin, and gold nanoparticles to determine its potential to promote regeneration of the intervertebral disc, specifically for nucleus pulposus regeneration.

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Polymer interlayer materials are utilized in laminated glass systems to provide increased resilience from blast incidents. The polymer chains within the interlayer material can benefit from material modifications that increase the crosslinking between adjacent chains. One theorized method of targeted crosslinking is made possible through a boron neutron capture process.

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Largemouth bass (LMB, 265-475 mm) were collected to document whether changes in fish condition and reproductive status influenced the concentration of total mercury (Hg) and selenium (Se) in axial muscle by season and sex. The fatty acid (FA) composition of fish was also examined to describe seasonal and sexual differences and identify whether arachidonic acid (ARA) could be used as a biomarker of Hg toxicity. There was a trend for females to have lower (p < 0.

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Purpose: Human data are limited linking magnesium (Mg) intake to the risk of non-alcoholic fatty liver disease (NAFLD). We aimed to examine the association between Mg intake and the risk of NAFLD among young adults in the US with a 25-year follow-up.

Methods: This study included 2685 participants from the Coronary Artery Risk Development in Young Adult (CARDIA) study.

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Surgical repair of the anterior cruciate ligament (ACL) can involve autograft or allograft materials. Allografts are typically chosen to avoid donor site morbidity associated with autografts harvest, but they can also result in a prolonged inflammatory period and delayed graft remodeling when compared to autografts. The aim of this study was to investigate the use of gold nanoparticles (AuNPs) conjugated to allografts to determine if AuNPs can reduce inflammation and enhance graft remodeling in an ovine model.

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Background And Purpose: Despite zinc's role as an antioxidant and anti-inflammatory agent, prospective studies relating zinc levels to ischemic stroke risk are lacking. To examine the association between serum zinc levels and incidence of ischemic stroke in a US population.

Methods: Using a case-cohort study nested within the Reasons for Geographic and Racial Differences in Stroke cohort, participants were randomly selected from the Reasons for Geographic and Racial Differences in Stroke cohort to generate a sub-cohort (n=2346).

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Purpose: This paper reviews the history of the radium dial workers in the United States, summarizes the scientific progress made since the last evaluation in the early 1990s, and discusses current progress in updating the epidemiologic cohort and applying new dosimetric models for radiation risk assessment.

Background: The discoveries of radiation and radioactivity led quickly to medical and commercial applications at the turn of the 20th century, including the development of radioluminescent paint, made by combining radium with phosphorescent material and adhesive. Workers involved with the painting of dials and instruments included painters, handlers, ancillary workers, and chemists who fabricated the paint.

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Background: It is unclear whether arsenic exerts adverse health effects on the kidney at low- and moderate- levels of exposure. We prospectively examined toenail arsenic concentrations measured during young adulthood in relation to incidence of chronic kidney disease (CKD) in midlife.

Methods: A total of 3768 participants (53 % female and 48 % blacks) in the Coronary Artery Risk Development in Young Adults (CARDIA) study were included.

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Background: Bromine is a naturally occurring element that is widely present in the human environment in various chemical forms primarily as flame retardants, pesticides, and water treatments.

Objective: In this exploratory study, we investigated the association of brain bromine concentrations on Alzheimer's disease (AD) neuropathology, cerebral infarcts, and Lewy bodies.

Methods: The study was conducted in 215 deceased participants of the Memory and Aging Project, a clinical-pathologic cohort study.

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The fast neutron spectrum was measured in an irradiation position adjacent to two F (fluorine-18) production targets at a medical cyclotron. The neutron spectrum was modeled using MCNP6 and experimentally determined using activation foils. A three-group neutron spectrum was determined using an over-determined least squares fitting method.

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Methylmercury (MeHg) is an environmental neurotoxin with human exposure mainly from dietary intake of contaminated fish. Exposure to MeHg has been implicated in neurological damage, but research on its role in cancers, specifically glioma, is limited. In a glioma case-control study, we examined associations between toenail mercury (Hg) and glioma risk.

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Cortical iron has been shown to be elevated in Alzheimer's disease (AD), but the impact of the directly measured iron on the clinical syndrome has not been assessed. We investigated the association between post-mortem iron levels with the clinical and pathological diagnosis of AD, its severity, and the rate of cognitive decline in the 12 years prior to death in subjects from the Memory and Aging Project (n = 209). Iron was elevated (β [SE] = 9.

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Soy lecithin has been shown to play a critical role in cell signaling and cellular membrane structure. In addition, it has been shown to increase biocompatibility, hydrophilicity, and decrease cytotoxicity. Gold nanoparticles have also shown to improve cellularity.

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Quantitative neutron capture radiography (QNCR) of B found in pre-dried maize samples has been conducted. Calibration standards constructed from filter paper mimicked plant tissues to reduce confounding matrix effects. A mathematical track elimination method improves the LOD as well as the visual contrast image at low boron concentration levels.

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Objectives: To examine the association between urinary cadmium levels and the incidence of ischemic stroke and to explore possible effect modifications.

Methods: A case-cohort study was designed nested in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, including 680 adjudicated incident cases of ischemic stroke and 2,540 participants in a randomly selected subcohort. Urinary creatinine-corrected cadmium concentration was measured at baseline.

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Background: Selenium is an essential trace element obtained through diet that plays a critical role in DNA synthesis and protection from oxidative damage. Selenium intake and polymorphisms in selenoproteins have been linked to the risk of certain cancers though data for glioma are sparse.

Methods: In a case-control study of glioma, we examined the associations of selenium in toenails and genetic variants in the selenoenzyme pathway with the risk of glioma and patient survival.

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Background: Although biologically plausible, epidemiological evidence linking exposure to methylmercury with increased risk of ischemic stroke is limited. The effects of methylmercury may be modified by selenium, which is an anti-oxidant that often co-exists with mercury in fish.

Objectives: To examine the association between serum mercury levels with the incidence of ischemic stroke and to explore the possible effect modifications by serum selenium levels and demographic and geographic factors.

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This pilot study represents a paradigm shift, using BNCT for the treatment of bacterial overgrowth on surgically implanted medical devices. In this study, titanium diboride disks were inoculated with S. aureus and irradiated in a thermal neutron beam.

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Objective: To determine whether an enhance recovery protocol for radical cystectomy patient affected the length of stay or the number and type of readmissions that occurred after hospital discharge.

Materials And Methods: We prospectively assessed 152 cystectomy patients after initiation of the pathway. These patients were compared with the previous 147 patient operated on before the pathway initiation.

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