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At least 19 recordsLinked to original sources

PubMed1976

The toxicity of brominated sesame oil and brominated soybean oil in miniature swine.

Miniature swine were fed brominated sesame oil at dietary levels of 0, 5, 25, 50 or 500 mg/kg of body weight for 17 weeks and brominated soybean oil at levels of 0, 5, 50 or 500 mg/kg of body weight for 28 weeks. Growth rate and food intake were decreased only at the high dose level in the brominated sesame oil study. In both studies, signs of lethargy and ataxia occurred in pigs fed the highest dose, and were probably due to a dose-related increase in serum bromine concentrations. Marked elevations in lactic dehydrogenase (LDH), serum glutamic-oxalacetic transaminase (SGOT) and serum glutamicpyruvic transaminase (SGPT) values were seen at the highest dose level with both substances and these enzyme activities were increased at the 50 mg/kg dose level in the brominated sesame oil study. Histopathologic lesions were confined to animals given the highest dose level of either oil. Marked fatty degeneration of the hepatic plate cells and renal tubular epithelial cells were seen in both studies. In the brominated sesame oil study, neutral fat was moderately increased in the myocardium of the pigs fed 500 mg/kg. However, marked diffuse accumulation of LDH, marked diffuse fatty degeneration and focal degeneration, and/or necrosis of individual or small groups of cardiac muscle fibers were seen in the group fed brominated soybean oil at 500 mg/kg. A moderate to marked testicular atrophy was also observed in this group. A dose-related accumulation of total and hexane-soluble bromine was observed in all tissues examined in both studies; the highest concentrations occurred in adipose tissue of the pigs given the highest dose level. Kidneys, livers, hearts and thyroids of these groups also contained large amounts of bromine. In pigs given the 50 mg/kg dose level, total and hexane-soluble bromine concentrations were higher in the brominated sesame oil study than in the longer brominated soybean oil study and may be responsible for the elevations in LDH, SGPT and SGOT activities in this group.

Animals↗

PubMed1978

[Sister chromatid exchanges following incorporation of bromine into cytosine DNA nucleotides. I. Combined use of 5-bromdeoxycytidine and thymidine for the purpose of incorporating bromine into DNA cytosine].

In the cultured in vitro human blood lymphocytes treated with 5-bromodeoxycytidine (BrdC) plus thymidine (dT) in concentrations of 0.05 mM and 0.4 mM, respectively, metaphases of the second division, containing chromosomes with differentially stained sister chromatids appear after a 30 hours treatment, attaining 85 per cent at 36 hours. Under the treatment with BrdC or BrdU alone, the similar percentage of metaphases is observed at 28 hours. Similar results are obtained if, at 16--18 hours, the culture medium, containing BrdC plus dT is either replaced with a medium free of both the precursors, or supplied once more vith (0.05 mM) or dC(0.05 mM). The The observed slowing movement of cells through out the cell cycle, due to the treatment with BrdC plus dT, is explained by the inhibitory effect of dT on DNA synthesis which is manifested as BrdC catabolism. It is concluded that BrdC administered together with the cell cycle-slowing doses of thymidine is predominantly incorporated into cytosine of DNA.

Bromodeoxycytidine↗

PubMed1975

A review of bromine determination in foods.

Organic compounds containing bromine, including methyl bromide, ethylene dibromide, and 1,2-dibromo-3-chloropropane, have been used extensively for the fumigation of foods, or soils in which foods grow, making it necessary to determine residues of bromine and bromine-containing organic compounds. A large number of methods for the determination of bromine in foods, as organic, inorganic, and combined total bromide, have been developed. In methods for organic bromide, the bromine is converted to the inorganic form for measurement by titration, photometry, or other means. In recent years, instrumental methods have been developed in which the total bromine in the sample is determined, regardless of the state in which it exists. X-ray fluorescence and neutron activation analysis are the 2 instrumental methods used most widely. Residue data are presented for some typical bromine-containing samples.

Activation Analysis↗

PubMed1978

The bromine enhancement ratio in mammalian cells in vitro and experimental mouse tumours.

Human kidney cells in culture and cells of mouse sarcoma-180 were allowed to incorporate bromine into their DNA. Cultured cells with and without incorporated BUdR were irradiated with electromagnetic radiations ranging in energy from 12 keV X-rays to 60Co gamma-rays to find out whether or not there exists any energy dependence of the bromine dose enhancement ratio BER. Such a dependence should show in the immediate neighbourhood of the K-absorption edge of bromine (13.5 keV). Any influence of the Auger effect triggered in bromine by external irradiation should show by a significant increase of the BER for energies rising from slightly below to slightly above the bromine K-edge. Values of D37, D0 and the extrapolation numbers of the cell survival curves served as biological endpoints. Measured values of BER ranged from 1.12-2.00 without any significant dependence energy. A weakly pronounced peak was found for 50 kV X-rays of 26 keV mean energy. Sarcoma-180 were irradiated with 14 kEV X-rays and 60C gamma-rays. BUdR was administered i.v., i.p. and directly into the tumours in quantities of up to 1 ml of a 10(-3) M solution. Tumour regression caused by the irradiations served as a measure of the radiation effects with and without incorporated BUdR. No significant dose enhancement effect of bromine was observed in this case. Within error limits, the combination of BUdR with 14 keV X-rays proved more effective than BUdR combined with 60Co gamma-rays.

Animals↗

PubMed1992

Comparison of bromine and permanganate as ultrastructural stains for lignin in plants infected by the fungus Colletotrichum lagenarium.

Transmission electron microscopy (TEM) and energy dispersive X-ray microanalysis (EDS) were used to localize manganese from KMnO4, and bromine, as ultrastructural stains for lignin in an herbaceous plant. The Spookie cultivar of pumpkin is susceptible to infection by the fungus Colletotrichum lagenarium and served as a model system to compare the Br and KMnO4 techniques. Bromine was used in a fixation/staining procedure, and in separate experiments, KMnO4 was used as either a fixative or as a postsection stain. The technique for using bromine was modified from the woody plant procedure by adding a paraformaldehyde prefixation step. With the bromine procedure, cell walls were well-preserved, but the cytoplasm was heavily extracted. The KMnO4 procedures produced well-fixed cytoplasm, but with some staining artifacts. With all procedures, EDS dot mapping demonstrated lignin deposition in the cell walls specifically associated with sites of fungal infection. Lignin was also localized in secondary walls of tracheary elements, sites known to be highly lignified. The bromine procedure provided the most specific localization of lignin with a minimum of artifact. The specific applications of these stains provided data on the ultrastructural localization of lignin which contributed to the elucidation of its role in the interactions between pathogenic fungi in both their resistant and susceptible plant hosts.

Bromine↗

PubMedDate not supplied

Bromine in human tissue.

The normal levels of bromine in human tissue are given and their use in the interpretation of levels found when over-exposure is a possibility is described. Bromine is "normally" distributed in human tissue as are essential trace elements. This allows a bromine (microgram) to chlorine (mg) ratio to be established (3.2) above which bromine exposure must be considered. The bromine concentrations in sections of hair can be used to establish the time of administration even when small amounts are ingested, but owing to the long half-life (about 15 days) found in human tissue interpretation after multiple doses may be difficult.

Bromine↗

PubMed1976

Initial fast reaction of bromine on reovirus in turbulent flowing water.

An apparatus is described for precise observation of the kinetics of the initial fast reaction of bromine with reovirus in turbulent flowing water. When quantitative electron microscopy shows that virus suspensions are essentially all single particles, the loss of infectivity follows first-order kinetics, the plaque titer falling at the rate of 3 log10 units/s at pH 7, 2 C, and at a 3-muM bromine concentration. Virus suspensions containing small aggregates (2 to 10/clump) exhibit a constantly decreasing disinfection rate with bromine. At a survival level of 10(-3) for single virions, the aggregated preparations have lost only 99% of their plaque titer and 10(-4) is reached only after 4 s of exposure. The disinfection rate does not appear to be a simple function of the size and frequency of aggregates in the virus suspension even when the aggregates contain no foreign material. Unpurified virus preparations (crude freeze-thaw lysates of infected cells) are shown, by zonal centrifugation, to contain 50% to over 90% of the infectivity in large, fast sedimenting aggregates. Such aggregates would strongly influence the bromine resistance of virus in polluted water.

Bromine↗

PubMed1978

The fate of brominated soya oil in the animal body.

1. The bromine-containing material accumulated in tissues of rats dosed with brominated soya oil gradually decreased when the oil was no longer administered. 2. G.l.c. of the transesterified ether extracts of tissues from dosed animals showed 9,10-dibromostearic acid in extracts from fat, heart, kidney, liver and muscle with much smaller amounts of 9,10,12,13-tetrabromostearic acid in all extracts except that from liver. 3. An ether-soluble bromine-containing metabolite excreted by rats dosed with brominated soya oil was tentatively identified as 5,6-dibromosebacic acid. 4. The same metabolite was excreted by rabbits, rats and marmosets dosed with 9,10-dibromostearic acid.

Animals↗

PubMed1992

Cholesterol modulation of lipid intermixing in phospholipid and glycosphingolipid mixtures. Evaluation using fluorescent lipid probes and brominated lipid quenchers.

Carbazole- and indole-labeled phospholipids have been used to monitor the homo- or heterogeneity of lipid mixing in several types of lipid bilayers combining a brominated and a nonbrominated lipid with varying amounts of cholesterol. Experimental quenching curves (relating the normalized probe fluorescence intensity to the mole fraction of brominated lipid) show a characteristic smooth, monophasic form for homogeneous liquid-crystalline lipid mixtures. However, for mixtures exhibiting lipid lateral segregation, such curves show marked perturbations in form over the region of composition where segregation occurs. Using this approach, it is found that high mole fractions of cholesterol (40-50 mol %) promote the formation of apparently homogeneous solutions in mixtures of disaturated and monounsaturated phosphatidylcholines (PCs) that exhibit extensive thermotropic phase separations in the absence of sterol. At only slightly lower levels of cholesterol, however, these systems exhibit inhomogeneous lipid mixing over a wide range of relative proportions of the two PC components. Mixtures of cerebroside and monounsaturated PCs, even at high bilayer cholesterol contents, exhibit significant inhomogeneity in lipid mixing over a wide range of cerebroside/PC ratios. Phase-separating PC/PC and PC/cerebroside mixtures can readily form long-lived metastable solutions when the level of the higher-melting component in the liquid-crystalline phase exceeds its equilibrium solubility by as much as 20-30 mol %; this tendency is significantly increased by cholesterol. Cholesterol shows no significant ability to enhance lipid intermixing in a third type of phase-separating lipid system, combining a monounsaturated PC with a monounsaturated phosphatidic acid--calcium complex. Experiments using cleavable phospholipid conjugates, linking a fluorescent lipid to a brominated lipid, suggest that each fluorescent molecule probes a local lipid domain comprising approximately less than 40-50 nearby acyl chains.

Animals↗

PubMed1976

Inactivation by bromine of single poliovirus particles in water.

Quantitative electron microscopy shows that Freon-extracted poliovirus, velocity banded in a sucrose gradient, contains over 95% single particles. This well-dispersed virus reacts quite rapidly with bromine in turbulent flowing water, losing plaque titer at the rate of one log10 unit in 10s at pH 7, 2 C, and at a bromine concentration of 2.2 muM. At 10 and 20 C the rate of disinfection (log10 plaque-forming units per second) is faster, and at both temperatures it increases in approximately linear fashion with increasing bromine concentration. At 2 C such a linear relationship is not observed.

Bromine↗

PubMed1975

Nature of the surviving plaque-forming unit of reovirus in water containing bromine.

The initial inactivation of reovirus in water containing 3 to 7 microns M bromine as HOBr was very rapid. Electron microscopy revealed extensive physical damage to the virions in as little as 1 min, but none were degraded beyond recognition. As treatment time continued, the reaction rate decreased toward a plateau of resistance, usually at about the 10-4 survival level; still no particles were lost. Progeny grown from these resistant plaque-forming units (PFU) were no more resistant to HOBr than the parent cultures. Small-number aggregation (adhering groups of two to ten virions counted by electron microscopy) had no detectable effect on the level of persistant PFU. Large aggregates seemed to be involved. Sonic treatment at 20 kHz after bromine exposure increased survival PFU titer 10- to 43-fold. Virus exposed to light centrifugation prior to bromine treatment did not show the plateau of resistance. Surviving PFU sedimented faster in a shallow sucrose gradient than single virions. Large aggregates were apparently too few to be counted by electron microscopy, but their penetration and inactivation must be achieved by any disinfectant chosen to rid water of reovirus.

Animals↗

PubMed1975

Micro-determination of bromine in biological samples using proton-induced x-ray emission spectroscopy.

The plasma level of bromine was measured by a proton-induced X-ray emission spectroscopy. Since bromine is the most difficult halogen to be determined and appears only in trace quantities, powerful techniques are required. The excellent reproducibility was obtained on 19 measurements on a sample of a single individual; the coefficient of variation was 6.3%. The average and standard deviation of plasma bromine levels on 47 young women were 0.50 and 0.10 mg/100 ml, respectively. Results by other methods in the literature were briefly reviewed.

Animals↗

PubMed1992

[Chronic consumption of brominated vegetable oils: their effect on liver secretion and catabolism of plasma lipoproteins].

We have previously reported that normal Wistar rats fed during 105 days with standard laboratory chow, supplemented with 0.5g of brominated vegetable oil (olive, sunflower) per 100 g of diet showed a significant increase of triglyceride and cholesterol content in both heart and liver. This was accompanied by a significant decrease of plasma lipid levels. Fluctuations in plasma triglyceride concentrations may be a result of either variations in the liver secretion rate of very low density lipoprotein-triglyceride (VLDL-TG), or changes in their removal rate by extrahepatic tissues or both. In the present work we have studied the contribution of both VLDL-TG secretion, and removal rates of plasma TG in the decrease of plasma TG levels, in rats fed during 105 days with a standard laboratory chow supplemented with 0.5 g per 100 g of brominated vegetable oil. VLDL-TG secretion was estimated by measuring the accumulation of plasma TG following the injection of TRITON WR 1339 and the removal rate of plasma TG by assaying plasma post-heparin lipolytic total (PHLA) and hepatic (H-TGL) lipase activities. In addition, the major lipid composition of plasma lipoprotein fractions were measured. Results were compared to those of a control group fed a laboratory chow diet during the same period of time. Our results show a decrease in both VLDL-TG secretion and plasma TG pool size accompanied by normal PHLA and H-TGL activities in animals fed the diet supplemented with brominated oils. However, the proportion of the major lipid components of the plasma lipoproteins fractions were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1977

[Aqueous chloride and bromine solutions as disinfectants: composition, redox potential, differences of reactivity (author's transl)].

A method is given to calculate the equilibrium concentrations of the molecules and ions emerging from the hydrolysis and dissociation of chlorine and bromine in aqueous soltuion. The differing influence the pH value and the initial (total) halogene concentration exerts to the HOX- and X2-equilibrium concentration is discussed. From the calculated equilibrium concentrations and tabulated standard reduction potentials the redox potentials of chlorine and bromine solutions at various pH values are calculated. No correlation between the reactivity and the redox potential of the two halogens was observed. Two possible explanations for the differing reactivity of chlorine and bromine against proteins are presented.

Bromine↗

PubMedDate not supplied

[Morphofunctional characteristics of the thyroid gland after correction of iodine and bromine deficiency].

Experiments were conducted on rats; morphofunctional changes of the thyroid gland in correction of iodine and bromine deficiency, depending on the regimen of the microelements administration in the course of a one-week cycle were studied. Daily administration of a one-week dose of iodine and bromine proved to be most effective in respect to the normalization of the morphofunctional condition of the thyroid gland in animals given iodine-deficient diet. The lowest thyroid gland weight, intensification of the synthetic processes in the thyrocytes, complete utilization of the thyroid gland iodine, and enrichment of the organism with trace elements were noted. Recommendations are given concerning the expediency of the change of regimen of iodine and bromine administration in group antigoiter prophylaxis.

Animals↗

PubMed1976

Investigation and identification of the bromination products of dimethoxyamphetamines.

The qualitative analysis of the aromatic bromination products of the 6 isomeric dimethoxyamphetamines and their hydrochloride or hydrobromide salts is described. Their ultraviolet, mass, and proton magnetic resonance spectra are not sufficiently different for distinction but infrared spectra allow a positive identification to be made and reference spectra are provided for the bromination products of 2,4-, 2,5-, 2,6-, 4,5-, and 3,5-dimethoxyamphetamines. The application of gas-liquid and thin layer chromatography for the analysis of these products is discussed. The bromination of 2,3-dimethoxyamphetamine consistently gave mixtures which could not be separated satisfactorily; spectra are included for completeness of the comparison of products.

DOM 2,5-Dimethoxy-4-Methylamphetamine↗

PubMed1992

Brominated phospholipids as a tool for monitoring the membrane insertion of colicin A.

The intrinsic fluorescence of the colicin A thermolytic fragment does not change after insertion into normal phospholipid vesicles and is thus an unsuitable probe for monitoring the membrane insertion process. In this paper, we report the results of studies on the quenching of this fluorescence by brominated dioleoylphosphatidylglycerol (Br-DOPG) vesicles. Bromine atoms located at the midpoint of the phospholipid acyl chain quench the tryptophan fluorescence, indicating contact between fluorophores of the protein and the bilayer's hydrophobic core. Addition of Br-DOPG vesicles to a protein solution quenches the tryptophan fluorescence in a time-dependent manner. This quenching can be fitted to a single-exponential function, and thus interpreted as a one-step process. This allows calculation of an apparent rate constant of protein insertion into the membrane. Parameters known to affect the insertion of the thermolytic fragment into phospholipid monolayers or vesicles (pH and negative charge density) also affect the rate constant in comparable ways. In addition to the information gained concerning membrane exposure in the steady state, this approach provides the first real-time method for measuring the insertion of colicin into membranes. It is highly quantitative and can be used on all versions of the protein, e.g., full size, proteolytic fragments, and mutants. Brominated lipids provide experimental conditions identical to normal lipids and allow for great flexibility in protein/lipid ratios and concentrations. The kinetic analysis shows clearly the existence of a two-step process involving a rapid adsorption of the protein to the lipid surface followed by a slow insertion.

Citrobacter freundii↗

PubMed1976

Active-site-directed inactivation of aromatase from human placental microsomes by brominated androgen derivatives.

Several brominated androgen derivatives were tested for their ability to inactivate microsomal aromatase from term human placenta. In the experimental protocol, the microsomal homogenate was incubated either with androstenedione or a brominated derivative of androstenedione (16alpha-bromo-6-ketoandrostenedione, 16alpha-bromoandrostenedione, 7alpha-(3'-bromoacetoxypropyl)androstenedione, 6alpha-bromoandrostenedione, or 6beta-bromoandrostenedione) and reduced nicotinamide adenine dinucleotide phosphate in a nitrogen saturated buffer composed of glycerol, ethylenediaminetetraacetic acid, and dithiothreitol in tris(hydroxymethyl)aminomethane hydrochloride (pH 7.4) under nitrogen at 4 degrees C with shaking. After the incubation period, the microsomes were recovered by centrifugation and washed once before determining aromatase specific activity. The brominated androgen derivatives which inactivated aromatase were 7alpha-(3'-bromoacetoxypropyl)androstenedione and 6alpha-bromoandrostenedione. The structures of 6alpha- and 6beta-bromoandrostenedione were unequivocally established by single crystal x-ray diffraction techniques. The extent of the enzyme inactivation by 6alpha-bromoandrostenedione was linearly proportional to the logarithm of its concentration. The evidence that this inactivation occurs at the aromatase active site is that androstenedione, when coincubated with 6alpha-bromoandrostenedione, protected aromatase from this inactivation. Progesterone provided much less protection than androstenedione. Furthermore, both 6alpha- and 6beta-bromoandrostenedione are competitive inhibitors of androstenedione aromatization, as determined by a Lineweaver-Burk plot, and 6alpha-bromoandrostenedione gives the same type I cytochrome P-450 binding spectrum with placental microsomes as androstenedione. These data suggest that 6alpha-bromandrostenedione is effective as an active-site-directed inhibitor of placental microsomal aromatase.

Androstenedione↗