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PubMed2001

Effects of brine injection wells, dry holes, and plugged oil/gas wells on chloride, bromide, and barium concentrations in the Gulf Coast Aquifer, southeast Texas, USA.

Data from 1,122 brine injection wells, 24,515 dry holes, 20,877 plugged oil/gas wells, and 256 water wells were mapped with a geographic information system (GIS) and statistically analyzed. There were 9, 107, and 58 water wells within 750 m of a brine injection well, dry hole, or plugged oil/gas well, respectively. Computed median concentrations were 157 mg/l for chloride, 0.8 mg/l for bromide, and 169 microg/l for barium. The maximum chloride concentration was 2,384 mg/l, close to 10 times the secondary drinking water standard. Shallow water wells and water wells near plugged oil/gas wells had significantly higher chloride and bromide levels.

Barium↗
PubMed2001

Induction of urinary excretion of 3-nitrotyrosine, a marker of oxidative stress, following administration of pyridostigmine bromide, DEET (N,N-diethyl-m-toluamide) and permethrin, alone and in combination in rats.

In this study, we determined levels of 3-nitrotyrosine in rat urine following administration of a single oral dose of 13 mg/kg pyridostigmine bromide (PB) (3-dimethylaminocarbonyloxy-N-methylpyridinum bromide), a single dermal dose of 400 mg/kg N,N-diethyl-m-toluamide (DEET) and a single dermal dose of 1.3 mg/kg permethrin, alone and in combination. Urine samples were collected from five treated and five control rats at 4, 8, 16, 24, 48, and 72 h following dosing. Solid-phase extraction coupled with high-performance liquid chromatography with ultraviolet detection at 274 nm was used for the determination of tyrosine and 3-nitrotyrosine. A single oral dose of PB and a single dermal dose of DEET or their combination significantly (P<0.05) increased levels of 3-nitrotyrosine starting 24 h after dosing compared with control urine samples. The maximum increase of 3-nitroytyrosine was detected 48 h after combined administration of PB and DEET. The ratio of 3-nitrotyrosine to tyrosine in urine excreted 48 h after dosing was 0.19+/-0.04, 0.20+/-0.05, 0.28+/-0.03, 0.32+/-0.04, 0.19+/-0.05, 0.42+/-0.04, 0.27+/-0.03, 0.36+/-0.04, and 0.48+/-0.04 following administration of water, ethanol, PB, DEET, permethrin, PB+DEET, PB+permethrin, DEET+permethrin, and PB+DEET+permethrin, respectively. The results indicate that an oral dose of PB and a dermal administration of DEET, alone and in combination, could generate free radical species, and thus increase levels of 3-nitrotyrosine in rat urine. Induction of 3-nitrotyrosine, a marker of oxidative stress, following exposure to these compounds could be significant in understanding the proposed enhanced toxicity following combined exposure to these compounds.

Administration, Oral↗
PubMed2002

Comparison of urinary bromide levels among people in East Asia, and the effects of dietary intakes of cereals and marine products.

Groups of people with no occupational exposure to Br-containing chemicals (29-54 year old, mostly women) in Japan, China and Korea, respectively, offered spot urine samples. Those in China and Korea offered 24 h duplicates of foods of the day. Urine samples were analyzed for Br by ECD-gas chromatography (ECD-GC) after derivatization to methyl bromide, and the Br-U was adjusted for a specific gravity of 1.016. Food intake data were based on national statistics and supplemented by the food duplicate data. Mean Br-U was 5.4 and 6.5 mg/l for Japanese men and women, respectively. Mean levels were in a range of 1.8-2.8 mg/l for four groups of Chinese, and 8-12 mg/l for the four groups of women in Korea. Br-U levels among Korean women were close levels reported for occupational exposure to 1- or 2-bromopropane, or methyl bromide. Regression analyses showed that Br-U levels were influenced by the intake of marine products (such as sea algae, sea fish and shellfish) and fruits, and inversely relate to intakes of cereals and potato.

Adult↗
PubMed1985

Liquid chromatographic determination of bromide in human milk and plasma.

A liquid chromatographic method for the determination of bromide present in human body fluids at the level of 0.5-5.0 ppm is presented. The method involves liquid--liquid extraction of lipids and other lipophilic compounds, destruction of the aqueous phase and analysis of the residue on an aminopropyl bonded silica column with UV detection at 214 nm. The method was applied to the analysis of 278 samples of Dutch human milk. Comparison of the results obtained with those from a routinely used colorimetric procedure for plasma indicated excellent agreement. The ease of automation of the described procedure and its excellent reproducibility make it a good alternative to existing methods for bromide analysis in body fluids.

Bromides↗
PubMed2000

Successful control with bromide of two patients with malignant migrating partial seizures in infancy.

A 3-month-old male and a 4-month-old female infant with intractable seizures were diagnosed as having malignant migrating partial seizures in infancy (MMPSI) with developmental arrest on the basis of characteristics of symptoms, clinical courses and EEGs. We treated these two patients with potassium bromide (80 mg/kg) after conventional antiepileptic drugs failed to adequately control the seizures. The potassium bromide therapy resulted in complete control of seizures in one patient, and more than 95% reduction in seizure frequency in the other.

Bromides↗
PubMed2004

The effect of bromide on the ultrastructure of rat thyrocytes.

Electron microscopic examination of thyroid tissue following administration of bromide to rats showed marked hypertrophy and hyperplasia in the thyrocytes, microfollicular rearrangement and lowered volume of colloid. The luminal surface of the thyrocytes showed increased size and number of microvilli, often filling the microlumen. Most of the nuclei were irregular in shape with unusual incisions and a higher density of chromatin. Proliferation of ER was seen with significantly dilated cisterns containing low electron density material. The Golgi complex was well developed and larger in rats receiving 10 mg Br/l drinking water (16 days) and 100 mg Br/l (16 and 66 days) than in control rats. Granules and small spherical structures (50-100 nm) appeared in the subapical part of the cytoplasm and their number increased in animals after administration of 50 mg Br-/l (16 and 66 days), 100 mg Br-/l (16 and 66 days), 200 and 400 mg Br-/l (133 days). In contrast, their number was reduced in thyrocytes of rats treated with 100 mg Br/l (16, 66 and 133 days). Colloid droplets were only rarely found. There was no significant change in the amount of mitochondria, secondary lysosomes including phagolysosomes. Some thyrocytes showed signs of necrosis in animals following administration of 10 mg Br/l (16 days, 100 and 400 mg Br/l, 133 days). Clusters of thyrocytes with spongy cytoplasm and bizarre shaped nuclei were found in groups treated with 100 mg Br/l, and 400 mg Br-/l (133 days). These changes, with previously published light microscopical, radioanalytical and biochemical findings, confirm the goitrogenic effect of bromide.

Animals↗
PubMed1997

Potassium bromide and the thyroid gland of the rat: morphology and immunohistochemistry, RIA and INAA analysis.

The increasing environmental concentration of bromine has resulted in attempts to obtain information on its possibly deleterious effect on humans, particularly on a major target organ of this halogen i.e. the thyroid gland. In order to establish the morphological and functional effects of bromine on the thyroid, we have performed experiments on male rats which, in addition to a standard diet with an estimated iodine/bromine content, were fed for periods of 16 and 66 days with the small quantities of bromide expected to be encountered in the environment (10, 50 and 100 mg of Br-/l in drinking water). This treatment induced growth of the follicular epithelial component and microfollicular tissue rearrangement, a reduction of intrafollicular colloid, an increase in the height of the follicular cells and the number of mitoses, and it enhanced vascularization. Image analysis revealed a significant reduction in the volume of colloid, despite the accompanying rise in the number of minute follicles. The immunohistochemical positivity of the thyroglobulin fell in the microfollicular colloid of the exposed animals, although this was affected to a lesser extent in the larger follicles. The concentration of bromine in the thyroid increased with the amount of bromine intake, while at the same time the molar ratio of iodine/bromine decreased. The plasma level of T4 was lowered after both 16 and 66 days of treatment, but the T3 level only after 66 days treatment. The level of TSH did not exhibit any significant change. The observed changes, which have a parenchymatous goitre-like character, may have a direct relevance for human medicine, since the concentrations of bromide chosen in these experiments are readily encountered in the environment.

Animals↗
PubMed2002

Single crystal EPR studies on Mn(II)-doped sarcosine cadmium chloride and sarcosine cadmium bromide: study of zero-field splitting tensor in iso-structural complexes.

EPR spectra of single crystals of Mn(II)-doped sarcosine cadmium chloride and sarcosine cadmium bromide are studied in Q-band and in X-band at room temperature. Two magnetically inequivalent sites are observed in both the lattices in a distorted octahedral environment. The spin-Hamiltonian parameters are extracted and are found to have a rhombic symmetry. The angular variation of the zero-field transitions is simulated for one of the sites with an asymmetric zero-field tensor D = 480 x 10(-4) cm(-1), E = -115 x 10(-4) cm(-1) and a = 10 x 10(-4) cm(-1) for Mn(II) in sarcosine cadmium chloride and with D = 460 x 10(-4) cm(-1) E = -98 x 10(-4) cm(-1) and a = 10 x 10(-4) cm(-1) for Mn(II) in sarcosine cadmium bromide. The observed large value of zero-field tensor is due to the steric effects of the crystal packing caused by the ligands. Matumura's plot predicts an average covalency of 8.8 and 7.7% for the manganese-ligand bond in SCC and SCB lattices respectively.

Bromides↗
PubMed1979

Fragmentation of the human transplantation antigen heavy chain by limited proteolysis, acid cleavage, and cyanogen bromide treatment.

Highly purified, papain-solubilized HLA-A, -B, and -C antigens comprising a mixture of a great number of allelic forms from at least three loci have been fragmented by limited proteolysis, acid cleavage, and cyanogen bromide treatment. Limited proteolysis of 125I-labeled HLA-A, -B, and -C antigens with trypsin, chymotrypsin, thermolysin, and pepsin resulted in the production of two large fragments. One fragment was associated with beta 2-microglobulin and contained all of the carbohydrate. The other fragment, which had a molecular weight of about 13,000, is most probably derived from the COOH-terminal part of the heavy chain. Acid cleavage of the HLA antigen heavy chain gave rise to two main fragments with molecular weights of 22,000 and 11,000. Both fragments contained disulfide bonds. Two minor components, representing further cleavage products of the 22,000-dalton fragment, were also observed. Cleavage of the HLA antigen heavy chain at methionyl residues gave rise to one carbohydrate-containing, cysteine-free 14,000-dalton fragment and one 20,000-dalton fragment that contained all cysteines but no carbohydrate. NH2-terminal amino acid sequence analyses demonstrated that the 22,000-dalton acid cleavage fragment and the 14,000-dalton cyanogen bromide fragment were derived from the NH2-terminal part of the HLA antigen heavy chain.

Amino Acid Sequence↗
PubMed1978

Amino acid sequence of two cyanogen bromide fragments of glycogen phosphorylase.

This communication presents the strategy and experimental details to prove the amino acid sequence of two large fragments of rabbit muscle glycogen phosphorylase generated by cleavage with cyanogen bromide. These fragments, CB18 and CB15, represent 241 of the 841 residues in the whole molecule. In addition to applying methods of automated liquid phase Edman degradation, techniques of selective immobilization and solid phase Edman degradation are used. One of the two cyanogen bromide fragments (CB15) contains two of the sites of cleavage with hydroxylamine which have proved to be important in the overall strategy of determining the complete sequence of this molecule. Together with the accompanying reports by Koide, A., et al., and Titani, K., et al. ((1978) Biochemistry 17 (first and third papers, respectively, in a series in this issue)), the present communication completes the proof of the amino acid sequence of phosphorylase and provides the basis for examining the relationship between its structure and function.

Amino Acid Sequence↗
PubMed1977

Amino acid sequence studies on the alpha chain of human fibrinogen. Characterization of 11 cyanogen bromide fragments.

The alpha chain of human fibrinogen consists of 600 +/- 25 amino acid residues, 10-11 of which are methionines. In this regard, we have identified and characterized 11 cyanogen bromide peptide fragments of 2, 3, 26, 28, 28, 37, 51, 56, 60 +/- 5, 64 +/- 5, and 260 +/- 20 residues, respectively. The sequences of five of these and a portion of a sixth have been reported previously. We now report the complete amino acid sequences of another of these fragments (56 residues), partial sequences for four others, and a preliminary characterization of the largest fragment. In a companion study (Doolittle, R. F., Cassman, K. G., Cottrell, B. A., Friezner, S. J., and Takagi, T. (1977), Biochemistry 16 (following paper in this issue)), we have obtained key overlap sequences from plasmic digests of fibrinogen which allow all but one of these cyanogen bromide peptides to be arranged in order. The sequences of some of these newly reported fragments have revealed an internal homology in the alpha chain, as well as structural similarities to the corresponding portions of the beta and gamma chains.

Amino Acid Sequence↗
PubMed2001

Human myeloperoxidase: structure of a cyanide complex and its interaction with bromide and thiocyanate substrates at 1.9 A resolution.

The 1.9 A X-ray crystal structure of human myeloperoxidase complexed with cyanide (R = 0.175, R(free) = 0.215) indicates that cyanide binds to the heme iron with a bent Fe-C-N angle of approximately 157 degrees, and binding is accompanied by movement of the iron atom by 0.2 A into the porphyrin plane. The bent orientation of the cyanide allows the formation of three hydrogen bonds between its nitrogen atom and the distal histidine as well as two water molecules in the distal cavity. The 1.85 A X-ray crystal structure of an inhibitory complex with thiocyanate (R = 0.178, R(free) = 0.210) indicates replacement of chloride at a proximal helix halide binding site in addition to binding in the distal cavity in an orientation parallel with the heme. The thiocyanate replaces two water molecules in the distal cavity and is hydrogen bonded to Gln 91. The 1.9 A structures of the complexes formed by bromide (R = 0.215, R(free) = 0.270) and thiocyanate (R = 0.198, R(free) = 0.224) with the cyanide complex of myeloperoxidase show how the presence of bound cyanide alters the binding site for bromide in the distal heme cavity, while having little effect on thiocyanate binding. These results support a model for a single common binding site for halides and thiocyanate as substrates or as inhibitors near the delta-meso carbon of the porphyrin ring in myeloperoxidase.

Binding, Competitive↗
PubMed2006

Bromide does not bind to the Mn4Ca complex in its S1 state in Cl(-)-depleted and Br(-)-reconstituted oxygen-evolving photosystem II: evidence from X-ray absorption spectroscopy at the Br K-edge.

Chloride is an important cofactor in photosynthetic water oxidation. It can be replaced by bromide with retention of the oxygen-evolving activity of photosystem II (PSII). Binding of bromide to the Mn(4)Ca complex of PSII in its dark-stable S(1) state was studied by X-ray absorption spectroscopy (XAS) at the Br K-edge in Cl(-)-depleted and Br(-)-substituted PSII membrane particles from spinach. The XAS spectra exclude the presence of metal ions in the first and second coordination spheres of Br(-). EXAFS analysis provided tentative evidence of at least one metal ion, which may be manganese or calcium, at a distance of approximately 5 A to Br(-). The native Cl(-) ion may bind at a similar distance. Accordingly, water oxidation may not require binding of a halide directly to the metal ions of the Mn complex in its S(1) state.

Bromides↗
PubMed1998

Reaction of myeloperoxidase compound I with chloride, bromide, iodide, and thiocyanate.

Myeloperoxidase plays a fundamental role in oxidant production by neutrophils. The enzyme uses hydrogen peroxide to oxidize chloride (Cl-), bromide (Br-), iodide (I-), and the pseudohalide thiocyanate (SCN-) to their respective hypohalous acids. This study for the first time presents transient kinetic measurements of the oxidation of these halides and thiocyanate by the myeloperoxidase intermediate compound I, using the sequential mixing stopped-flow technique. At pH 7 and 15 degrees C, the two-electron reduction of compound I to the native enzyme by Cl- has a second-order rate constant of (2.5 +/- 0.3) x 10(4) M(-1) s(-1), whereas reduction of compound I by SCN- has a second-order rate constant of (9.6 +/- 0.5) x 10(6) M(-1) s(-1). Iodide [(7.2 +/- 0.7) x 10(6) M(-1) s(-1)] is shown to be a better electron donor for compound I than Br- [(1.1 +/- 0.1) x 10(6) M(-1) s(-1)]. The pH dependence studies suggest that compound I reduction by (pseudo-)halides is controlled by a residue with a pKa of about 4.6. The protonation of this group is necessary for optimum (pseudo-)halide anion oxidation. These transient kinetic results are underlined by steady-state spectral and kinetic investigations. SCN- is shown to be most effective in shifting the system myeloperoxidase/hydrogen peroxide from the peroxidatic cycle to the halogenation cycle, whereas iodide is shown to be more effective than bromide which in turn is much more effective than chloride. Decreasing pH increases the rate of this transition. Our results show that thiocyanate is an important substrate of myeloperoxidase in most environments and that hypothiocyanate is likely to contribute to leukocyte antimicrobial activity.

Anions↗
PubMed2004

Chlorination byproduct formation in the presence of humic acid, model nitrogenous organic compounds, ammonia, and bromide.

The formation of trihalomethanes (THMs), haloacetic acids (HAAs), and cyanogen halides (CNXs) after chlorination of synthetic solutions containing humic acid, nitrogenous organic (N-organic) compounds, ammonia, and bromide ions was studied. Humic acid (from Aldrich) was used to provide the source of the precursors. Glycine was chosen as the primary model N-organic compound and other four model N-organic compounds (including glutamic acid, glycylglycine, diethylamine, and methylamine) were also evaluated for comparison. The formation of THMs and HAAs was found to decrease with increasing glycine and ammonia concentrations but to increase with increasing bromide ion concentration. CNX formation was found to be highly sensitive to free chlorine to glycine ratios, and its formation trends were significantly affected bythe presence/absence of ammonia. The incorporation of bromine changed the byproducts speciation toward brominated species and enhanced the yields of total THMs, HAAs, and CNXs. Different model N-organic compounds exerted different effects on the formation of THMs, HAAs, and CNXs. Their effects on the formation of THMs and HAAs were likely dependent on their reactivity to chlorine in competing with the humic acid chlorination reactions. The difference in the CNCI yields was attributable to the variations in the compound structures.

Ammonia↗
PubMed2001

Use of WO(4)(2-) on layered double hydroxides for mild oxidative bromination and bromide-assisted epoxidation with H(2)O(2).

Tungstate, exchanged on a (Ni,Al) layered double hydroxide, is applied as a heterogeneous catalyst in the oxidation of bromide with H(2)O(2) and the ensuing electrophilic bromination of olefins. The high halogenation activity of the catalyst in essentially neutral conditions mimicks the activity of V-bromoperoxidase enzymes. In water, aromatic and aliphatic olefins are selectively converted to bromohydrins; in methanol, methoxybromides are produced. In appropriate solvent conditions, the bromohydroxylation of geminally di-, tri-, and tetrasubstituted olefins proceeds via dehydrobromination to the epoxide. Evidence for this mechanism is provided by kinetic and labeling experiments. This one-pot alternative for the two-step halohydrin epoxidation process is enabled by the mild pH conditions; bromide is effective in substoichiometric, catalytic amounts. All new catalytic procedures are characterized by a high oxidative stability of the catalyst, high productivity of the catalyst on weight basis, high W turnover frequencies in ambient conditions (up to 50 mol of product per W per h), and high chemo-, regio-, and stereoselectivities.

Alkenes↗
PubMed2006

Iron-catalyzed homocoupling of bromide compounds.

The homocoupling of bromide compounds was successfully performed in one pot by a combination of metallic magnesium and a catalytic amount of iron salts. The binary catalytic system differentiates itself from other homocoupling reactions catalyzed by iron salts in that it requires neither the in situ preparation of Grignard reagent nor the addition of a 1,2-dihalogen compound as an oxidant. Various aromatic and alkyl bromides underwent the homocoupling smoothly affording the corresponding symmetrical hydrocarbon compounds in moderate to excellent yields.

Bromides↗
PubMed2006

Palladium(0)-catalyzed suzuki-miyaura cross-coupling reactions of potassium aryl- and heteroaryltrifluoroborates with alkenyl bromides.

Efficient palladium(0)-catalyzed Suzuki-Miyaura cross-couplings are described. The reactions involving potassium aryl- and heteroaryltrifluoroborates with alkenyl bromides can generally be carried out using < or =2 mol % of palladium catalyst and 3 equiv of base in toluene/H2O. When stereodefined alkenyl bromides are employed, the resulting styrene derivatives are accessed stereospecifically. A variety of functional groups are tolerated in both coupling partners.

Alkenes↗