Potentiating effects of manganese dioxide on experimental respiratory infections

Maigetter, Robert Z.; Ehrlich, R.; Fenters, James D.; Gardner, Donald E.

doi:10.1016/0013-9351(76)90100-6

Cited by 40 publications

(22 citation statements)

References 6 publications

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“…In rodents, inhalation of insoluble Mn at milligram concentrations impairs pulmonary bacterial clearance and increases bacterial-associated host mortality (30). Other studies have demonstrated that exposure of hosts already bearing a viral lung infection for 24 or 48 hr prior to a 3-hr exposure to insoluble Mn had a shorter time to death than their air-exposed counterparts (38,39). Furthermore, although the effects of soluble Mn on alveolar Mø function are still being debated, in vitro studies have demonstrated reductions in phagocytic activity.…”

Section: Discussionmentioning

confidence: 99%

A role for associated transition metals in the immunotoxicity of inhaled ambient particulate matter.

Zelikoff

Schermerhorn

Fang

et al. 2002

Environ Health Perspect

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Epidemiologic studies demonstrate that infection, specifically pneumonia, contributes substantially to the increased morbidity and mortality among elderly individuals following exposure to ambient particulate matter (PM). This laboratory has previously demonstrated that a single inhalation exposure of Streptococcus pneumoniae-infected rats to concentrated ambient PM 2.5 (particulate matter with aerodynamic diameter ≤ 2.5 µm) from New York City (NYC) air exacerbates the infection process and alters pulmonary and systemic immunity. Although these results provide some basis for explaining the epidemiologic findings, the identity of specific PM constituents that might have been responsible for the worsening pneumonia in exposed hosts remains unclear. Thus, studies were performed to correlate the physicochemical attributes of ambient PM 2.5 with its in vivo immunotoxicity to identify and characterize the role of constitutive transition metals in exacerbating an ongoing streptococcal infection. Uninfected or previously infected rats were exposed in the laboratory to soluble divalent Fe, Mn, or Ni chloride salts. After exposure, uninfected rats were sacrificed and their lungs were lavaged. Lungs from infected hosts were used to evaluate changes in bacterial clearance and effects of exposure on the extent/severity of infection. Results demonstrated that inhalation of Fe altered innate and adaptive immunity in uninfected hosts, and both Fe and Ni reduced pulmonary bacterial clearance in previously infected rats. The effects on clearance produced in infected Fe-exposed rats were similar to those seen in infected rats exposed to ambient NYC PM. Taken together, these studies demonstrate that inhaled ambient PM can worsen the outcome of an ongoing pulmonary infection and that associated Fe may play some role in the immunotoxicity.

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Section: Discussionmentioning

confidence: 99%

A role for associated transition metals in the immunotoxicity of inhaled ambient particulate matter.

Zelikoff

Schermerhorn

Fang

et al. 2002

Environ Health Perspect

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“…When these criteria are met, the extrapolation to a similar effect, i.e., increased pulmonary infections occurring in man, becomes reasonable providing the microorganism present is capable of multiplying and invading that host and that the actual dose of the inhaled pollutant reaching these defenses is sufficient to cause an adverse effect. Evidence exists that a number of trace metals which alter either biochemical, physiological, morphological or functional mechanisms of the macrophage also cause a significant increase in susceptibility to infection. Examples of some of the particles that have been shown to cause an enhancement of bacterial pulmonary infection include: Ni2 I, Cd2 +, Zn2 +, Pb2 +, H2SO4 and coal fly ash (35,37,55,62,74,117,132,219,222,225). It is important to note that in many of these studies, dose-response data indicated that an effect could be produced with concentrations similar to those seen in the working environ-ment.…”

Section: The Bottom Linementioning

confidence: 99%

“…A number of different experimental approaches, using intact animals, have been employed in an effort to determine the degree of efficiency of the pulmonary defense system in the pollutant-exposed, compromised host (61,63,134,141,(218)(219)(220)(221)(222)(223).…”

Section: The Bottom Linementioning

confidence: 99%

Alterations in Macrophage Functions by Environmental Chemicals

Gardner¹

1984

Environmental Health Perspectives

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“…This system has been efficiently utilized in environmental toxicologic studies of ozone (9, 10), nitrogen dioxide (11), irradiated auto smog (12), and trace metals, such as NiO and MnO2 (13,14). This model has been successfully employed to enhance the pulmonary infectivity in mice (10,11,13,14), rats (15), hamsters (11), and squirrel monkeys (16).…”

Section: Introductionmentioning

confidence: 99%

“…This model has been successfully employed to enhance the pulmonary infectivity in mice (10,11,13,14), rats (15), hamsters (11), and squirrel monkeys (16). Among the infectious agents eliciting this reaction in the above animals are Streptococcus pyogenes, Klebsiella pnedmoniae, Diplococcus pneumoniae, and influenza PR-8 virus.…”

Section: Introductionmentioning

confidence: 99%

Time-Dose Response for Nitrogen Dioxide Exposure in an Infectivity Model System

Coffin¹,

Gardner²,

Blommer³

1976

Environmental Health Perspectives

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The concentration of NO; in polluted atmosphere is subject to wide variation, according to peak traffic load, industrial productivity, intensity of sunlight and meteorological conditions. Normally NO2 has a low basal concentration with superimposed spikes when the above conditions are optimal for its production. Thus, it is important to determine the relative importance of a short-term, relatively high concentration of NO2 versus exposure for longer periods of minimal dose levels. This problem was approached experimentally by measuring the effect of NO on an animal's resistance to the induction of bacterial pneumonia. The data collecteA indicate that: (1) in short-term dose-response studies using the same Ct (concentration x time) product of 7, the actual concentration exerts a greater influence on NO2 effect than does the duration of exposure; (2) when concentration is held constant and the time increased, the average difference in mortality from controls can be seen after only 1 hr exposure to 3.5 ppm and after 3 weeks of exposure to 0.5 ppm; and (3) the relative mean survival time at 3.5 ppm for 1 hr was 18-36 hr less than that of the control animals.

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Potentiating effects of manganese dioxide on experimental respiratory infections

Cited by 40 publications

References 6 publications

A role for associated transition metals in the immunotoxicity of inhaled ambient particulate matter.

A role for associated transition metals in the immunotoxicity of inhaled ambient particulate matter.

Alterations in Macrophage Functions by Environmental Chemicals

Time-Dose Response for Nitrogen Dioxide Exposure in an Infectivity Model System

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