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R M Maiorino

Bio: R M Maiorino is an academic researcher from University of Arizona. The author has contributed to research in topics: Toxaphene & Dimercaprol. The author has an hindex of 22, co-authored 30 publications receiving 1373 citations.

Papers
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Journal ArticleDOI
TL;DR: The Dimaval-mercury challenge test holds great promise as a diagnostic test for mercury exposure, especially for low level mercurialism.

255 citations

Journal ArticleDOI
TL;DR: The experimental results support the hypothesis that DMPS competes with endogenous ligands for MMA(III), forming a DMPS-MMA complex that is readily excreted in the urine and points out the need for studying the biochemical toxicology of MMA( III).

139 citations

Journal ArticleDOI
TL;DR: In this paper, the relative effectiveness or therapeutic index of these compounds in protecting mice from the lethal effects of an LD99 of sodium arsenite is DMSA greater than DMPS, DMPA more than DMPA, and N-(2,3-dimercaptopropyl )-phthalamidic acid (DMPA) greater than BAL in the magnitude of 42:14:4:1, respectively.

106 citations

Journal ArticleDOI
TL;DR: There was a positive correlation between the amount of mercury excreted and the amalgam score and DMPS might be useful for increasing the urinary excretion of mercury and thus increasing the significance and reliability of this measure of mercury exposure.
Abstract: Meso-2,3-dimercaptosuccinic acid (DMSA) is bound to plasma albumin in humans and appears to be excreted in the urine as the DMSA-cysteine mixed disulfide. The pharmacokinetics of DMSA have been determined after its administration to humans po. For the blood, the tmax and t1/2 were 3.0 h + 0.45 SE and 3.2 h + 0.56 SE, respectively. The Cmax was 26.2 microM + 4.7 SE. To determine whether dental amalgams influence the human body burden of mercury, we gave volunteers the sodium salt of 2,3-dimercaptopropane-1-sulfonic acid (DMPS). The diameters of dental amalgams of the subjects were determined to obtain the amalgam score. Administration of 300 mg DMPS by mouth increased the mean urinary mercury excretion of subjects over a 9 h period. There was a positive correlation between the amount of mercury excreted and the amalgam score. DMPS might be useful for increasing the urinary excretion of mercury and thus increasing the significance and reliability of this measure of mercury exposure. DMSA analogs have been designed and synthesized in attempts to increase the uptake by cell membranes of the DMSA prototype chelating agents. The i.v. administration of the monomethyl ester of DMSA, the dimethyl ester of DMSA or the zinc chelate of dimethyl DMSA increases the biliary excretion of platinum and cadmium in rats.

104 citations

Journal Article
TL;DR: The easily performed DMPS-mercury challenge test is useful for monitoring dental personnel for mercury vapor exposure and is a better indicator of exposure and renal mercury burden than is the mercury level measured in the urine before DMPS is given.
Abstract: The sodium salt of 2,3-dimercaptopropane-1-sulfonic acid (DMPS) challenge test (300 mg p.o. after an 11-hr fast) was given in Monterrey, Mexico to dental and nondental personnel. Urine samples were collected and analyzed for total mercury. The mean mercury urinary excretion (+/- S.E.) for 6 hr before and 6 hr after DMPS administration for 10 dental technicians, who formulate amalgam, was 4.84 micrograms +/- 0.742 and 424.0 micrograms +/- 84.9; for 5 dentists, who use amalgam in their practice, 3.28 micrograms +/- 1.11 and 162.0 micrograms +/- 51.2; and for 13 nondental personnel, 0.783 microgram +/- 0.189 and 27.3 micrograms +/- 3.19. The urinary coproporphyrin levels before DMPS administration, which are indicative of renal mercury content, were quantitatively associated with the urinary mercury levels among the three study groups after DMPS administration. This was not so if the urinary mercury level before DMPS administration was compared with the urinary coproporphyrin concentration. The urinary mercury level after DMPS administration is a better indicator of exposure and renal mercury burden than is the mercury level measured in the urine before DMPS is given. Regression analysis showed that the coefficient of urinary mercury was statistically and adversely associated with complex attention (switching task), the perceptual motor task (symbol-digit substitution), symptoms and mood. The easily performed DMPS-mercury challenge test is useful for monitoring dental personnel for mercury vapor exposure.

83 citations


Cited by
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Journal ArticleDOI
16 Aug 2002-Talanta
TL;DR: This review deals with environmental origin, occurrence, episodes, and impact on human health of arsenic, a metalloid occurs naturally, being the 20th most abundant element in the earth's crust.

3,166 citations

Journal ArticleDOI
TL;DR: An overview of redox and non-redox metal-induced formation of free radicals and the role of oxidative stress in toxic action of metals is provided.

2,429 citations

Journal ArticleDOI
TL;DR: A better understanding of the mechanism(s) of action) of arsenic will make a more confident determination of the risks associated with exposure to this chemical.

1,460 citations

Journal ArticleDOI
TL;DR: In this paper, the role of antioxidant defence systems against arsenic toxicity is discussed, and the role role of vitamin C (ascorbic acid), vitamin E (α-tocopherol), curcumin, glutathione and antioxidant enzymes such as superoxide dismutase, catalase, and peroxidase in their protective roles against arsenic-induced oxidative stress is also discussed.
Abstract: Arsenic (As) is a toxic metalloid element that is present in air, water and soil. Inorganic arsenic tends to be more toxic than organic arsenic. Examples of methylated organic arsenicals include monomethylarsonic acid [MMA(V)] and dimethylarsinic acid [DMA(V)]. Reactive oxygen species (ROS)-mediated oxidative damage is a common denominator in arsenic pathogenesis. In addition, arsenic induces morphological changes in the integrity of mitochondria. Cascade mechanisms of free radical formation derived from the superoxide radical, combined with glutathione-depleting agents, increase the sensitivity of cells to arsenic toxicity. When both humans and animals are exposed to arsenic, they experience an increased formation of ROS/RNS, including peroxyl radicals (ROO•), the superoxide radical, singlet oxygen, hydroxyl radical (OH•) via the Fenton reaction, hydrogen peroxide, the dimethylarsenic radical, the dimethylarsenic peroxyl radical and/or oxidant-induced DNA damage. Arsenic induces the formation of oxidized lipids which in turn generate several bioactive molecules (ROS, peroxides and isoprostanes), of which aldehydes [malondialdehyde (MDA) and 4-hydroxy-nonenal (HNE)] are the major end products. This review discusses aspects of chronic and acute exposures of arsenic in the etiology of cancer, cardiovascular disease (hypertension and atherosclerosis), neurological disorders, gastrointestinal disturbances, liver disease and renal disease, reproductive health effects, dermal changes and other health disorders. The role of antioxidant defence systems against arsenic toxicity is also discussed. Consideration is given to the role of vitamin C (ascorbic acid), vitamin E (α-tocopherol), curcumin, glutathione and antioxidant enzymes such as superoxide dismutase, catalase and glutathione peroxidase in their protective roles against arsenic-induced oxidative stress.

1,040 citations

ReportDOI
01 Aug 2007

824 citations