Polymorphonuclear leukocytes (PMN) isolated from human blood were exposed to various levels of hydrogen sulfide. The effect on respiratory burst, myeloperoxidase activity, and capacity to phagocytose and kill bacteria were studied. A 1-h exposure of the PMN to 1 mM sulfide did not decrease their myeloperoxidase activity or their capacity to initiate a respiratory burst. Actually the products of...

Microbial activity associated with produced water from hydraulic fracturing operations can lead to gas souring and corrosion of carbon-steel equipment. We examined the microbial ecology of produced water and the prospective role of the prevalent microorganisms in corrosion in a gas production field in the Barnett Shale. The microbial community was mainly composed of halophilic, sulfidogenic bac...

A field of growing interest in environmental health is that of lead speciation, the study of the various chemical forms of lead. Different lead compounds have different solubilities, which in turn affect bioavailability. Descriptions of lead exposure such as concentrations in air or settled dust are telling quantities, but can only relate part of the story. A variety of biological and geochemic...

Hydrogen sulfide is gaining acceptance as an endogenously produced modulator of tissue function. The present paradigm of H(2)S (diprotonated, gaseous form of hydrogen sulfide) as a tissue messenger consists of H(2)S being released from the desulfhydration of l-cysteine at a rate sufficient to maintain whole tissue hydrogen sulfide concentrations of 30 microM to >100 microM, and these tissue con...

Chicken liver mitochondria consumed O2 at an accelerated rate when supplied with low concentrations of hydrogen sulfide. Maximum respiration occurred in 10 microM sulfide, and continued more slowly up to concentrations as high as 60 microM. Sulfide oxidation was coupled to adenosine triphosphate (ATP) synthesis, as shown by firefly luciferase luminescence and by measurement of the mitochondrial...

Vesicomyid clams, vestimentiferans, and some bathymodiolin mussels from hydrothermal vents and cold seeps possess thiotrophic endosymbionts, high levels of hypotaurine and, in tissues with symbionts, thiotaurine. The latter, a product of hypotaurine and sulfide, may store and/or transport sulfide non-toxically, and the ratio to hypotaurine plus thiotaurine (Th/[H+Th]) may reflect an animal's su...

Heavy metals pollution is one of the key environmental problems. In this research, the effect of seed priming with salicylic acid and sodium hydrosulfide was investigated on methionine and arginine amino acids contents and some compounds derived from their metabolism as well as ZmACS6 and ZmSAMD transcripts levels in maize plants under lead stress. For this purpose, maize seeds were soaked in s...

Hydrogen sulfide is an essential gasotransmitter associated with numerous pathologies. We assert that hydrogen sulfide plays an important role in regulating macrophage function in response to subsequent inflammatory stimuli, promoting clearance of leukocyte infiltrate and reducing TNF-α levels in vivo following zymosan-challenge. We describe two distinct methods of measuring leukocyte hydrogen ...

Respiration of plume tissue of the hydrothermal vent tube worm Riftia pachyptila is insensitive to sulfide poisoning in contrast to tissues of animals that do not inhabit vents. Permeability barriers may not be responsible for this insensitivity since plume homogenates are also resistant to sulfide poisoning. Cytochrome c oxidase of plume, however, is strongly inhibited by sulfide at concentrat...

Anti-oxidant cellular defenses have typically been considered an obligatory protective response to the Great Oxidation Event (GOE) some 600 million years ago. However, recent evidence suggests that the earliest forms of Life arose sometime between 3.7 and 1.9 billion years ago, long before the GOE [1,2]. The earth's environment during the Arachean and Proterozoic periods contained ferrunginous ...