Author
Rodney R. Dietert
Other affiliations: University of Texas at Austin, North Carolina State University
Bio: Rodney R. Dietert is an academic researcher from Cornell University. The author has contributed to research in topics: Immune system & Immunotoxicology. The author has an hindex of 41, co-authored 161 publications receiving 4954 citations. Previous affiliations of Rodney R. Dietert include University of Texas at Austin & North Carolina State University.
Topics: Immune system, Immunotoxicology, Antigen, Disease, Microbiome
Papers published on a yearly basis
Papers
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TL;DR: Differential windows of vulnerability during development are identified in the context of available animal models as well as changes in target organ sensitivities to toxicant effects on the immune and respiratory systems.
Abstract: Fetuses, infants, and juveniles (preadults) should not be considered simply "small adults" when it comes to toxicological risk. We present specific examples of developmental toxicants that are more toxic to children than to adults, focusing on effects on the immune and respiratory systems. We describe differences in both the pharmacokinetics of the developing immune and respiratory systems as well as changes in target organ sensitivities to toxicants. Differential windows of vulnerability during development are identified in the context of available animal models. We provide specific approaches to directly investigate differential windows of vulnerability. These approaches are based on fundamental developmental biology and the existence of discrete developmental processes within the immune and respiratory systems. The processes are likely to influence differential developmental susceptibility to toxicants, resulting in lifelong toxicological changes. We also provide a template for comparative research. Finally, we discuss the application of these data to risk assessment.
314 citations
TL;DR: It is demonstrated that functional immaturity alone predisposes the young to infection, and the developing immune system was found to be at greater risk than that of the adult, either because lower doses produced immunotoxicity, adverse effects were more persistent, or both.
Abstract: It is well established that human diseases associated with abnormal immune function, including some common infectious diseases and asthma, are considerably more prevalent at younger ages. Although not established absolutely, it is generally believed that development constitutes a period of increased immune system susceptibility to xenobiotics, since adverse effects may occur at lower doses and/or immunomodulation may be more persistent, thus increasing the relative risk of xenobiotic exposure to the immunologically immature organism. To address this issue, a brief overview of immune matura- tion in humans is provided to demonstrate that functional immaturity alone predisposes the young to infection. Age-dependent differences in the immunotoxic effects of five diverse compounds, diethylstilbestrol (DES), diazepam (DZP), lead (Pb), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and tributyltin oxide (TBTO), which have undergone adult and developmental immunotoxicity testing in rodents, are then reviewed, as are human data when available. For all five chemicals, the develop- ing immune system was found to be at greater risk than that of the adult, either because lower doses produced immunotox- icity, adverse effects were more persistent, or both. It is well established that diseases associated with abnormal immune function, including com- mon infectious diseases and asthma, are considerably more prevalent at younger ages. Several fac- tors are thought to account for this increased susceptibility, including functional immaturity of the immune system and age-related differences in the integrity of the host's anatomical and functional barriers. Although not established absolutely, it is generally believed that the immature immune sys- tem is also more susceptible to xenobiotics than the fully mature system, and that sequela of devel- opmental immunotoxicant exposure may be particularly persistent, in contrast to effects observed following adult exposure, which generally occur at higher doses and are expected to resolve soon after exposure ends. Based on experimental animal studies, perturbations of the developing immune system may be manifested as a qualitative (i.e., affecting the developing immune system without affecting the adult immune system) or a quantitative (i.e., affecting the developing immune system at lower doses than in adults) difference. Immune maturation may simply be delayed by
167 citations
TL;DR: This review considers the animal and human evidence that lead exposure can produce a stark shift in immune functional capacity with a skewing predicted to elevate the risk of atopic and certain autoimmune diseases.
Abstract: The heavy metal lead is a widely deposited environmental toxicant known to impact numerous physiological systems, including the reproductive, neurological, hepatic, renal, and immune systems. Studies illustrating the capacity of lead to impair immune function and/or host resistance to disease date back to at least the 1960s. However, it has only been in recent years that lead has been recognized among a new category of immunotoxicants-those that dramatically shift immune functional capacity while producing only modest changes to immune cell populations and lymphoid organs. These relatively noncytotoxic immunomodulating chemicals and drugs represent the immunotoxic hazards most difficult to identify and problematic for risk assessment using historic approaches. As a result, such environmental factors are also among the most likely to contribute to chronic immune-related disease at relevant exposure levels. This review considers the animal and human evidence that lead exposure can produce a stark shift in immune functional capacity with a skewing predicted to elevate the risk of atopic and certain autoimmune diseases. At the same time, host defenses against infectious agents and cancer may be reduced. Age-based exposure studies also suggest that levels of blood lead previously thought to be safe, that is, below 10 microg/dl, may be associated with later life immune alterations.
155 citations
TL;DR: The results suggest that at the Pb dosage employed, the embryo may be more sensitive to the full range of Pb-induced immunotoxic effects with late gestational Pb exposure, and the effects of P b on DTH function are more pronounced in females.
137 citations
TL;DR: Genetic variation in the ability to recruit and activate peritoneal macrophages was examined in seven partially developed 15I5-B congenic White Leghorn chicken lines and suggest that the chicken major histocompatibility complex may influence certain properties of chicken macrophage function.
Abstract: Genetic variation in the ability to recruit and activate peritoneal macrophages was examined in seven partially developed 15I5-B congenic White Leghorn chicken lines. While the ability to generate peritoneal exudate cells (PECs) was similar in all lines, major differences were observed in the numbers, composition, and functional activity of harvestable peritoneal adherent cell populations. In response to a general stimulant, Sephadex, lines .7-2 and .6-2 produced the greatest numbers of adherent peritoneal cells while lines .C-12 and .15I-5 were among the poorest responders. Macrophage percentage of adherent PECs varied between lines. 15I5 chickens produced a consistently high percentage of adherent macrophages while .6-2 birds exhibited the lowest macrophage percentage at all ages examined. Phagocytosis was used as one measure of the level of macrophage activation and similar results were obtained using both opsonized and unopsonized sheep erythrocytes; adherent peritoneal cells from lines .6-2, .7-2, and .P-13 exhibited the highest activity and .C-12, .15I-5, and background 15I5(B15) lines produced cells with the lowest phagocytic activity. In a second functional assay, the killing of Salmonella typhimurium, macrophage-rich cells from line .P-13 exhibited the lowest activity which was significantly lower than that obtained with cells from lines .6-2 and .15I-5. Antigen-specific stimulation of peritoneal adherent cells by ferritin also showed that .C-12 was a low responder in contrast with other lines. The results indicate that these genetic lines differ in peritoneal macrophage function and suggest that the chicken major histocompatibility complex may influence certain properties of chicken macrophage function.
136 citations
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TL;DR: This year's edition of the Statistical Update includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association’s 2020 Impact Goals.
Abstract: Background: The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovas...
5,078 citations
TL;DR: The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascul...
Abstract: Background: The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascul...
3,034 citations
TL;DR: A draft genome sequence of the red jungle fowl, Gallus gallus, provides a new perspective on vertebrate genome evolution, while also improving the annotation of mammalian genomes.
Abstract: We present here a draft genome sequence of the red jungle fowl, Gallus gallus. Because the chicken is a modern descendant of the dinosaurs and the first non-mammalian amniote to have its genome sequenced, the draft sequence of its genome--composed of approximately one billion base pairs of sequence and an estimated 20,000-23,000 genes--provides a new perspective on vertebrate genome evolution, while also improving the annotation of mammalian genomes. For example, the evolutionary distance between chicken and human provides high specificity in detecting functional elements, both non-coding and coding. Notably, many conserved non-coding sequences are far from genes and cannot be assigned to defined functional classes. In coding regions the evolutionary dynamics of protein domains and orthologous groups illustrate processes that distinguish the lineages leading to birds and mammals. The distinctive properties of avian microchromosomes, together with the inferred patterns of conserved synteny, provide additional insights into vertebrate chromosome architecture.
2,579 citations
TL;DR: The strategy of using food additives to protect farm animals from the toxin may also provide effective and economical new approaches to protecting human populations.
1,624 citations
TL;DR: The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update as discussed by the authors .
Abstract: The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2022 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population and an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, and the global burden of cardiovascular disease and healthy life expectancy.Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.
1,483 citations