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M.H. Samitz

Bio: M.H. Samitz is an academic researcher from University of Pennsylvania. The author has contributed to research in topics: Chromium & Hexavalent chromium. The author has an hindex of 10, co-authored 17 publications receiving 249 citations.

Papers
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Journal ArticleDOI
TL;DR: Baetjer, Damron and Budacz as mentioned in this paper investigated the interactions of both tri-and hexavalent chromium with lung tissue, and found that only trivalent was bound to the tissue.

55 citations

Journal ArticleDOI
TL;DR: Two factors must be taken into account in order to interpret the results of patch test reactions of chromate-sensitive subjects to trivaient chromium compounds: the penetrability of the compound through the epidermal barrier and the concentrations of the test solutions.

34 citations

Journal ArticleDOI
TL;DR: The nickel uptake of these modified epidermis powders as compared to the untreated material indicates that carboxyl groups are involved in the binding of nickel to a greater extent than are amino groups.

34 citations

Journal ArticleDOI
05 Mar 1973-JAMA
TL;DR: It is suggested that nickel released from the stainless steel screws (a tenable thesis because Ferguson and co-workers 3 and Mears 4 have reported increased nickel concentrations in parenchymal tissues from implantation of stainless steel rods containing nickel) produced the allergic reaction.
Abstract: To the Editor.— Two letters relating to this subject were published recently inThe Journal. 1,2 The following comments are pertinent to this problem. Barranco and Soloman 1 reported a case of eczematous dermatitis from internal exposure to nickel from a stainless steel screw in the patella. (Nickel sensitivity was demonstrated by patch testing: pure nickel, 3% nickel sulfate, and pieces of the stainless steel screw gave positive results; test results were negative with metallic salts such as potassium dichromate, cobalt sulfate, and mercuric chloride.) The stainless steel contained 14% nickel. Following removal of the screws, the dermatitis subsided within 72 hours. This would imply that nickel released from the stainless steel screws (a tenable thesis because Ferguson and co-workers 3 and Mears 4 have reported increased nickel concentrations in parenchymal tissues from implantation of stainless steel rods containing nickel) produced the allergic reaction. Fisher, on the other hand, rejected

22 citations

Journal ArticleDOI
TL;DR: The mechanism for the inactivation of hexavalent chromium by ascorbic acid involves reduction to trivalent Chromium and subsequent complex formation of the trivalents species.
Abstract: The mechanism for the inactivation of hexavalent chromium by ascorbic acid involves reduction to trivalent chromium and subsequent complex formation of the trivalent species. Ascorbic acid and hexavalent chromium react in a ratio of 5:2. This is slightly less than could be expected for oxidation of all the ascorbic acid to dehydroascorbic acid. The chromium-ascorbic acid complex exhibits a strong absorption near 390mμ. The 7:3 ratio may indicate a polymeric species in which the chromium is bound to more than one ascorbic acid molecule.

17 citations


Cited by
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Journal ArticleDOI
TL;DR: The chemical nature of chromium compounds and how these properties impact upon the interactions ofchromium with cellular and genetic targets, including animal and human hosts, are discussed.
Abstract: Chromium, like many transition metal elements, is essential to life at low concentrations yet toxic to many systems at higher concentrations. In addition to the overt symptoms of acute chromium tox...

504 citations

Journal ArticleDOI
TL;DR: One of the most promising research directions deals with the administration of citrulline as a more efficient alternative to arginine, especially against underlying splanchnic sequestration of amino acids.
Abstract: Citrulline (Cit, C6H13N3O3), which is a ubiquitous amino acid in mammals, is strongly related to arginine. Citrulline metabolism in mammals is divided into two fields: free citrulline and citrullinated proteins. Free citrulline metabolism involves three key enzymes: NO synthase (NOS) and ornithine carbamoyltransferase (OCT) which produce citrulline, and argininosuccinate synthetase (ASS) that converts it into argininosuccinate. The tissue distribution of these enzymes distinguishes three “orthogonal” metabolic pathways for citrulline. Firstly, in the liver, citrulline is locally synthesized by OCT and metabolized by ASS for urea production. Secondly, in most of the tissues producing NO, citrulline is recycled into arginine via ASS to increase arginine availability for NO production. Thirdly, citrulline is synthesized in the gut from glutamine (with OCT), released into the blood and converted back into arginine in the kidneys (by ASS); in this pathway, circulating citrulline is in fact a masked form of arginine to avoid liver captation. Each of these pathways has related pathologies and, even more interestingly, citrulline could potentially be used to monitor or treat some of these pathologies. Citrulline has long been administered in the treatment of inherited urea cycle disorders, and recent studies suggest that citrulline may be used to control the production of NO. Recently, citrulline was demonstrated as a potentially useful marker of short bowel function in a wide range of pathologies. One of the most promising research directions deals with the administration of citrulline as a more efficient alternative to arginine, especially against underlying splanchnic sequestration of amino acids. Protein citrullination results from post-translational modification of arginine; that occurs mainly in keratinization-related proteins and myelins, and insufficiencies in this citrullination occur in some auto-immune diseases such as rheumatoid arthritis, psoriasis or multiple sclerosis.

497 citations

OtherDOI
TL;DR: The sections in this article are: Manifestations of Skin Permeability, Structure of the Skin, Effect of Solvents and Surfactants, and Regional Variations in Permeable.
Abstract: The sections in this article are: 1 Manifestations of Skin Permeability 2 Structure of the Skin 2.1 Relevant Structural Features of the Whole Skin 3 The Stratum Corneum 3.1 Regional Variations in Structure 4 Human Versus Other Mammalian Skin 5 Biophysics of Skin Permeability 5.1 Mathematical Analysis of Skin Permeability 5.2 Steady-State Permeability of Skin—Fick's Law 5.3 Appendageal Diffusion 5.4 Concentration Levels in the Skin 5.5 Regional Variations in Permeability 6 Effect of Solvents and Surfactants 6.1 Water 6.2 Aprotic Solvents 6.3 Surfactants 6.4 Organic Solvents

481 citations

Book
01 Oct 1998
TL;DR: Ecological and toxicological aspects of silver (Ag) and silver salts in the environment are briefly summarized with an emphasis on natural resources.
Abstract: : Selective review and synthesis of the technical literature on copper and copper salts in the environment and their effects primarily on fishes, birds, mammals, terrestrial and aquatic invertebrates, and other natural resources. The subtopics include copper sources and uses; chemical and biochemical properties; concentrations of copper in field collections of abiotic materials and living organisms; effects of copper deficiency; lethal and sublethal effects on terrestrial plants and invertebrates, aquzatic organisms, birds, and mammals, including effects on survival, growth, reproduction, behavior, metabolism, carcinogenicity, mutagenicity, and teratogenicity; proposed criteria for the protection of human health and sensitive natural resources; and recommendations for additional research.

463 citations

Journal ArticleDOI
TL;DR: From the failure to select lymphocytes directed specifically against a chromium determinant of a particular valence it is concluded that by sensitization with chromium salts of different valences a common determinant or closely related determinants are formed.

345 citations