Publications by authors named "David A Geier"

DNA alterations in gametes, which may occur either spontaneously or as a result of exposure to genotoxicants, can lead to constitutional chromosomal anomalies in the offspring. Alcohol is an established genotoxicant. The goal of this hypothesis-testing longitudinal cohort study was to evaluate the effect of significant/sustained maternal alcohol exposure on clinically diagnosed constitutional chromosomal anomalies among children diagnosed with fetal alcohol syndrome (FAS).

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This study examined the impact of mercury (Hg) vapor exposure from amalgams among all American pregnant women. Amalgam-Hg vapor exposure among 1,665,890 weighted-pregnant women ( = 37) was examined in the 2015-2020 National Health and Nutrition Examination Survey (NHANES). Correlation coefficients between amalgam surfaces and daily micrograms (µg) of urinary Hg excretion and daily µg of Hg vapor exposure from amalgams per kilogram (Kg) bodyweight were calculated.

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Environmental mercury exposure possesses a significant risk to many human populations. At present there are no effective treatments for acute mercury toxicity. A new compound, N,N'bis-(2-mercaptoethyl) isophthalamide (NBMI), a lipophilic chelating agent was created to tightly/irreversibly bind mercury.

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Background: The gut microbiome may play an important role in the etiology and progression of colon cancer. The present hypothesis-testing study compared the colon cancer incidence rate among adults diagnosed with intestinal (formerly (Cdiff) (the Cdiff cohort) to adults not diagnosed with intestinal Cdiff infection (the non-Cdiff cohort).

Methods: De-identified eligibility and claim healthcare records within the Independent Healthcare Research Database (IHRD) from a longitudinal cohort of adults (the overall cohort) enrolled in the Florida Medicaid system between 1990 through 2012 were examined.

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Glyphosate-based herbicides (GBHs) are one of the most commonly used herbicides worldwide. Numerous in vitro and in vivo model system studies have demonstrated endocrine-disrupting chemical (EDC) properties associated with glyphosate/GBH exposure. The present hypothesis-testing study evaluated the potential inverse dose-dependent relationship between increasing urinary glyphosate and decreasing concentrations of blood sex hormones.

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Background: This hypothesis-testing study evaluated the relationship between fetal alcohol syndrome (FAS) and neurodevelopmental disorder (ND) diagnoses within the Independent Healthcare Research Database (IHRD).

Methods: De-identified eligibility and claim healthcare records prospectively generated from the 1990-2012 Florida Medicaid system were analyzed using SAS software. There were 89,766 children continuously eligible with ≥10 outpatient office visits during the 120 month period following birth in the cohort examined.

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The vaccine effectiveness (VE) of childhood measles-mumps-rubella (MMR) vaccine to reduce childhood rubella infections in the US during the 1990s/2000s was undertaken in a retrospective longitudinal cohort study. SAS and StatsDirect software were utilized to examine non-identifiable linked eligibility and claim healthcare records prospectively generated from the Florida Medicaid system in the Independent Healthcare Research Database (IHRD). A total of 33 839 children received a single MMR vaccination (vaccinated) and 44 154 children never received a rubella-containing vaccine (unvaccinated) were continuously eligible from 1990 to 2009 for Florida Medicaid within the first 10 years following birth.

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Mercury (Hg)-based amalgam is a dental restorative material in common use. This hypothesis-testing study evaluated the relationship between dental amalgam exposure and the risk of reported asthma diagnoses in American adults. A total of 97,861,577 weighted-persons with one or more dental amalgam surfaces (exposed group) and 31,716,558 weighted-persons with one or more other dental surfaces (no dental amalgams, unexposed group) were examined in the 2015-2016 National Health and Nutrition Examination Survey.

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Introduction: Autism spectrum disorder (ASD) is defined by persistent deficits in communication, socialization, and stereotypic behaviors. It was previously hypothesized that hormone dysfunction is a frequent occurrence among children diagnosed with an ASD.

Objectives: A hypothesis-testing epidemiological study examined the relationship between precocious puberty (PP) (a known disorder of childhood sex hormone dysfunction) and ASD diagnoses.

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This hypothesis-testing study evaluated the relationship between mercury (Hg)-based dental amalgams and arthritis diagnoses among adults in the United States (US). A total of 86 305 425 weighted-persons with ⩾1 dental amalgam filling surface (DAFS) (exposed group) and 32 201 088 weighted-persons with ⩾1 other dental filling surface (ODFS) (no DAFS, unexposed group) were examined in the 2015 to 2016 National Health and Nutritional Examination Survey (NHANES). All persons were 20 to 80 years-old with known demographic characteristics and arthritis status.

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Background: Measles (rubeola) is a highly contagious infectious disease with significant morbidity/mortality. Measles-Mumps-Rubella (MMR) is a live-attenuated vaccine used in the United States (US) to prevent measles. This retrospective longitudinal cohort study evaluated childhood MMR vaccination and the risk of a seizure episode and seizure disorder.

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Background: Mercury has many direct and well-recognized neurotoxic effects. However, its immune effects causing secondary neurotoxicity are less well-recognized. Mercury exposure can induce immunologic changes in the brain indicative of autoimmune dysfunction, including the production of highly specific brain autoantibodies.

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A novel virus named 2019 novel coronavirus (2019-nCoV/SARS-CoV-2) causes symptoms that are classified as coronavirus disease (COVID-19). Respiratory conditions are extensively described among more serious cases of COVID-19, and the onset of acute respiratory distress syndrome (ARDS) is one of the hallmark features of critical COVID-19 cases. ARDS can be directly life-threatening because it is associated with low blood oxygenation levels and can result in organ failure.

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Autism spectrum disorder (ASD) is defined by persistent deficits in social communication/interaction and stereotypic behaviors with many diagnosed persons experiencing a developmental regression at >1 year‑old. It was hypothesized that progressive childhood encephalopathy is an important etiological factor in ASD pathogenesis. This hypothesis‑testing study examined the relationship between diagnosed childhood encephalopathy and ASD.

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Scientific research can provide us with factual, repeatable, measurable, and determinable results. As such, scientific research can provide information that can be used in the decision-making process in the care of patients and in public policy. Although it has been suggested that ethylmercury (CHHg)-containing compounds do not cross the blood-brain barrier (BBB), this review examines the literature that addresses the question as to whether ethylmercury-containing compounds cross the BBB.

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Autism spectrum disorder (ASD) is a neurodevelopmental disorder in which evidence reveals oxidative stress and transsulfuration pathway abnormalities. Down syndrome (DS) is a genetic disorder characterized by similar oxidative stress and transsulfuration pathway abnormalities. This hypothesis-testing longitudinal cohort study determined whether transsulfuration abnormalities and oxidative stress are important susceptibility factors in ASD etiology by evaluating the rate of ASD diagnoses in DS as compared to the general population.

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Cognitive health is an emerging public health concern for the aging American population. Mercury (Hg) is a toxic element that can cause nervous system damage. This hypothesis-testing study evaluated the relationship between blood ethyl-Hg levels and cognitive decline in an older adult and elderly American population.

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Background: Measles (rubeola) is a highly contagious disease with significant morbidity/mortality. Measles-Mumps-Rubella (MMR) is a live-attenuated vaccine used in the United States (US) since the early 1970s to prevent measles infection. This retrospective longitudinal cohort study examined childhood MMR vaccination effectiveness (VE) on preventing diagnosed measles cases.

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Objectives: Asthma is a chronic disorder that affects persons of all ages impacting the quality of their lives. This cross-sectional hypothesis-testing study evaluated the relationship between human papillomavirus vaccine and the risk of an incident asthma diagnosis in a defined temporal period post-vaccination.

Methods: The 2015-2016 National Health and Nutrition Examination Survey data were examined for a group of 60,934,237 weighted persons between 9 and 26 years old in Statistical Analysis Software.

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Studies suggest a relationship between exposure to endocrine disrupters, such as mercury (Hg), and premature puberty. Hg exposure from Thimerosal-containing hepatitis B vaccine, administered at specific intervals within the first six months of life, and the child's long-term risk of being diagnosed with premature puberty (ICD-9 code: 259.1), was retrospectively examined, using a hypothesis-testing, longitudinal case-control design on prospectively collected data, in the Vaccine Safety Datalink (VSD).

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Influenza is an acute respiratory disease with significant annual global morbidity/mortality. Influenza transmission occurs in distinct seasonal patterns suggesting an importance of climate conditions on disease pathogenesis. This hypothesis-testing study evaluated microenvironment conditions within different demographic/geographical groups on seasonal influenza deaths in the United States.

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Cerebral hypoperfusion, or insufficient blood flow in the brain, occurs in many areas of the brain in patients diagnosed with autism spectrum disorder (ASD). Hypoperfusion was demonstrated in the brains of individuals with ASD when compared to normal healthy control brains either using positron emission tomography (PET) or single‑photon emission computed tomography (SPECT). The affected areas include, but are not limited to the: prefrontal, frontal, temporal, occipital, and parietal cortices; thalami; basal ganglia; cingulate cortex; caudate nucleus; the limbic system including the hippocampal area; putamen; substantia nigra; cerebellum; and associative cortices.

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Investigators postulated that early-life exposure to organic mercury (Hg) significantly increases the risk of childhood neurodevelopmental disorders (NDs). The Vaccine Adverse Event Reporting System database was utilized to conduct a hypothesis testing case-control study by evaluating 3486 total adverse event reports reported following Haemophilus influenza type b (Hib) vaccination. Exposed subjects received a Thimerosal-containing formulation (HIBTITER™, Wyeth-Lederle), while unexposed subjects received a Thimerosal-free formulation (PEDVAXHIB™, Merck).

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Nelson and Bauman (Pediatrics 111:674-679, 2003) previously hypothesized that pervasive developmental disorder (PDD) was not associated with mercury (Hg) exposure because the medical conditions associated with Hg exposure were not associated with PDD. A hypothesis-testing longitudinal case-control study evaluated the frequency of medically diagnosed conditions previously associated with Hg poisoning, including: epilepsy, dysarthria, failure to thrive, cerebral palsy, or contact dermatitis and other eczema among children preceding their eventual PDD diagnosis (cases) compared to controls. A retrospective examination of medical records within the Vaccine Safety Datalink (VSD) was undertaken.

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