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PubMed2002

The relationship of oral malodor in patients with or without periodontal disease.

BACKGROUND: Halitosis has been correlated with the concentration of volatile sulfur compounds (VSC) produced in the oral cavity by metabolic activity of bacteria colonizing the periodontal area and the dorsum of the tongue. The aim of this study was to determine whether there is some relationship between the presence of N-benzoyl-DL-arginine-2-napthylamide (BANA)-positive species Treponema denticola, Porphyromonas gingivalis, and Bacteroides forsythus and clinical and oral malodor parameters. METHODS: Twenty-one subjects (21 to 59 years old) with probing depths (PD) > 3.0 mm and 20 subjects (21 to 63 years old) with PD < or = 3.0 mm (controls) participated. The quality of the mouth air was assessed organoleptically, and a portable sulfide monitor was used to measure the concentration of VSC. Clinical parameters, plaque index (PI) and gingival index (GI), were obtained from 6 teeth. Samples for BANA test were taken from the dorsal surface of the tongue, saliva, and the 6 reference teeth. RESULTS: The scores of PI, GI, subgingival samples that tested positive for BANA hydrolyzing species, organoleptic ratings, and VSC values were significantly higher in the subjects with PD > 3.0 mm (P < 0.01, Mann-Whitney U test). There was a correlation between BANA hydrolysis by subgingival plaque bacteria and VSC values (r = 0.55, P < 0.01), and between GI and VSC values (r = 0.48, P < 0.05) in patients with PD > 3.0 mm. There was no significant correlation between these parameters in the control group. CONCLUSION: These results confirm that the BANA hydrolyzing bacteria in the subgingival plaque are an important source of malodor production in the oral cavity.

Adult↗
PubMed2004

Use of a novel group of oral malodor measurements to evaluate an anti-oral malodor mouthrinse (TriOralTM) in humans.

OBJECTIVE: This study compared the ability of a test mouthwash containing zinc chloride and sodium chlorite (TriOral) to reduce intrinsic oral malodor, to that of two other mouthrinses, one with zinc chloride only and the other with no zinc chloride/no sodium chlorite, using a novel group of oral malodor parameter measurements. METHODOLOGY: Forty-eight subjects completed the study; 16 in the test group, 17 in the zinc only group, and 15 in the no zinc chloride/ no sodium chlorite group. At baseline and after two and four weeks, parameters assessed were 1) malodorants in the headspace of and in solution in resting whole saliva determined organoleptically, 2) breath volatile sulfur compounds (VSC) measured with a sulfide monitor (Halimeter), 3) fresh and incubated saliva oxidation-reduction potential (E(h)) measured with a platinum electrode, and 4) level of saliva indolic compounds (IC), indole and skatole, determined colorimetrically with Kovac's reagent. The VSC, E(h), and IC data for the three mouthrinses were analyzed statistically by repeated measures ANOVA between groups, and by 2-way ANOVA within groups. Corresponding organoleptic data were analyzed by Kruskal-Wallis and Friedman non-parametric tests. RESULTS: Organoleptic, VSC, and E(h) evaluations clearly showed the zinc chloride/sodium chlorite test mouthrinse to be more effective than the other two rinses. In all cases, the level of significance was p < 0.001 between the test mouthrinse and its no zinc chloride/no sodium chlorite control; between test mouthrinse and the zinc chloride only product, significance was p < 0.05, < 0.001 and < 0.01 for the organoleptic, VSC, and E(h) tests, respectively. Noteworthy was the observation that the mean organoleptic saliva headspace score with the test mouthrinse was reduced to zero, and VSC levels fell below 50 ppb S by the end of the study, a level where the breath is usually non-odorous. The test mouthwash also appeared more effective in reducing the salivary IC levels, but the results did not reach significance at p < 0.05 unless IC levels were amplified in the saliva by incubation overnight at 37 degrees C. Correlations between the various procedures were highly significant, achieving in almost all cases a probability level of p < 0.001. CONCLUSION: The results supported the conclusion that the zinc chloride plus sodium chlorite mouthrinse (TriOral) is more effective in reducing oral malodor than a zinc chloride alone mouthrinse, and even more effective than its no zinc chloride/no sodium chlorite mouthrinse control. The methods used in this study were consistent with one another, and highly effective in measuring various parameters that characterize oral malodor.

Adult↗
PubMed1977

Identification of dihydrothiazoles in urine of male mice.

The compounds 2-isopropyl-4,5-dihydrothiazole and 2-sec-butyl-4,5-dihydrothiazole were identified in urine of male mice. Their excretion in mouse urine is sex-dependent. In the urine of female mice the two dihydrothiazoles are either absent or present only in trace amounts. The analytical procedure includes the adsorption of the volatile mouse urine constituents on Tenax GC, their gas chromatographic separation and the detection of the sulfur compounds by the sulfur-specific detector. The identified compounds were synthesized. Natural and synthetic compounds had the same mass spectrometric properties and retention data.

Animals↗
PubMed2005

Kinetics and stoichiometry of sulfide oxidation by sewer biofilms.

Oxidation of sulfide under aerobic conditions by biofilms grown on municipal wastewater in 6 identical pipe reactors was investigated. The biofilms were grown at pH 7.6 and temperatures of 20 and 25 degrees C under aerobic-anaerobic transient conditions with pulse dosing of sulfide in the bulk water. The pulse dosing of sulfide served to simulate conditions in a gravity sewer located downstream of a pressure main. During growth of the biofilms, sulfide was pulse dosed in concentrations of 0, 0.5, 2.0 and 5.0 g Sm(-3) with a frequency of 1h(-1). Based on a series of batch experiments, kinetics and stoichiometry of sulfide oxidation by the sewer biofilms was investigated and a rate equation and a stoichiometric constant proposed. Sulfide oxidation kinetics was significantly faster for biofilms grown at sulfide loadings of 0.5, 2.0 and 5.0 g Sm(-3)h(-1) than for biofilms grown in the absence of sulfide. However, the kinetics of sulfide oxidation was relatively constant for biofilms grown at sulfide loadings above 0.5 g Sm(-3)h(-1). Mass balance calculations of dissolved oxygen and sulfur compounds suggested the oxidation product to be elemental sulfur. Further oxidation of elemental sulfur could not be documented.

Biofilms↗
PubMed2003

Desulfurization of transportation fuels with zeolites under ambient conditions.

Deep desulfurization of transportation fuels (gasoline, diesel, and jet fuels) is being mandated by U.S. and foreign governments and is also needed for future fuel cell applications. However, it is extremely difficult and costly to achieve with current technology, which requires catalytic reactors operated at high pressure and temperature. We show that Cu+ and Ag+ zeolite Y can adsorb sulfur compounds from commercial fuels selectively and with high sulfur capacities (by pi complexation) at ambient temperature and pressure. Thus, the sulfur content was reduced from 430 to <0.2 parts per million by weight in a commercial diesel at a sorbent capacity of 34 cubic centimeters of clean diesel produced per gram of sorbent. This sulfur selectivity and capacity are orders of magnitude higher than those obtained by previously known sorbents.

Journal Article↗
PubMed2005

Sulfur accumulation in the timbers of King Henry VIII's warship Mary Rose: a pathway in the sulfur cycle of conservation concern.

In marine-archaeological oak timbers of the Mary Rose large amounts of reduced sulfur compounds abound in lignin-rich parts such as the middle lamella between the cell walls, mostly as thiols and disulfides, whereas iron sulfides and elemental sulfur occur in separate particles. Synchrotron-based x-ray microspectroscopy was used to reveal this environmentally significant accumulation of organosulfur compounds in waterlogged wood. The total concentration of sulfur in reduced forms is approximately 1 mass % throughout the timbers, whereas iron fluctuates up to several mass %. Conservation methods are being developed aiming to control acid-forming oxidation processes by removing the reactive iron sulfides and stabilizing the organosulfur compounds.

Archaeology↗
PubMed2005

Anti-thyroid drugs and thyroid hormone synthesis: effect of methimazole derivatives on peroxidase-catalyzed reactions.

Syntheses and characterization of the selenium analogue (MSeI) of anti-thyroid drug methimazole and a series of organoselenium compounds bearing N-methylimidazole pharmacophore are described. In contrast to the sulfur compound that exists predominantly in its thione form, the selenium analogue exists in a selenol form, which spontaneously oxidizes in air to produce the corresponding diselenide. The reduction of the diselenide by GSH or NaBH(4) affords the biologically active selenol, which effectively inhibits the lactoperoxidase (LPO) activity in vitro. The monoselenides having N-methylimidazole moiety are found to be much less active than the selenol, suggesting that the presence of a selenol moiety is important for the LPO inhibition. The kinetic and mechanistic studies reveal that MSeI inhibits the LPO activity by reducing the H(2)O(2), providing a novel method to reversibly inhibit the enzyme. Although MSeI strongly inhibits LPO, the enzyme's activity can be completely recovered by increasing the H(2)O(2) concentration. On the other hand, the inhibition by methimazole (MMI), the sulfur analogue, cannot be reversed by increasing the H(2)O(2) concentration, leading to a complete inactivation of the enzyme. The reversible inhibition of LPO by some of the selenium derivatives is correlated with their glutathione peroxidase (GPx) activity, and the high GPx activity of the selenium compounds as compared with their sulfur analogues suggests that the selenium derivatives may protect the thyroid gland from oxidative damage.

Antithyroid Agents↗
PubMed1987

Sulfate reduction in peat from a new jersey pinelands cedar swamp.

Microbial sulfate reduction rates in acidic peat from a New Jersey Pine Barrens cedar swamp in 1986 were similar to sulfate reduction rates in freshwater lake sediments. The rates ranged from a low of 1.0 nmol cm day in February at 7.5- to 10.0-cm depth to 173.4 nmol cm day in July at 5.0- to 7.5-cm depth. The presence of living Sphagnum moss at the surface generally resulted in reduced rates of sulfate reduction. Pore water sulfate concentrations and water table height also apparently affected the sulfate reduction rate. Concentrations of sulfate in pore water were nearly always higher than those in surface water and groundwater, ranging from 26 to 522 muM. The elevated pore water sulfate levels did not result from the evapotranspiratory concentration of infiltrating stream water or groundwater, but probably resulted from oxidation of reduced sulfur compounds, hydrolysis of ester sulfates present in the peat, or both. The total sulfur content of peat that had no living moss at the surface was 164.64 +/- 1.5 and 195.8 +/- 21.7 mumol g (dry weight) for peat collected from 2.5 to 5.0 and 7.5 to 10.0 cm, respectively. Organosulfur compounds accounted for 84 to 88% of the total sulfur that was present in the peat. C-bonded sulfur accounted for 91 to 94% of the organic sulfur, with ester sulfate being only a minor constituent. Reduced inorganic sulfur species in peat from 2.5 to 7.5 cm were dominated by H(2)S-FeS (68%), while pyritic sulfide was the predominant inorganic sulfur species in the peat from depths of 7.5 to 10.0 cm (75%).

Journal Article↗
PubMedDate not supplied

Occupational exposure to chemical and biological agents in the nonproduction departments of pulp, paper, and paper product mills: an international study.

As part of an international epidemiological study of workers in the pulp and paper industry, previously unpublished exposure measurements were assembled in a database. This article describes 7293 measurements in nonproduction departments from 147 mills in 11 countries. The greatest variety of agents was measured in the maintenance, construction, and cleaning department, where high exposures to asbestos, chromium [VI] compounds, copper, mercury in urine, nitrogen dioxide, ozone, styrene, sulfur dioxide, trichloroethylene, and welding fumes were observed. Measurements in the storage, yard, loading, and shipping department indicated high exposures to asbestos, carbon monoxide, fungal spores, nitrogen oxides, sulfur dioxide, and total dust. The steam and power generation department had high exposures to methyl mercaptan, silica, and total dust. Measurements in process and effluent water treatment, laboratory and research, engineering, and office, administration, and cafeteria areas had few elevated exposures. Throughout the nonproduction departments, measurements of pulp-production chemicals such as chlorine and sulfur compounds tended to be low, with many below detection limits. There were some problems with the available data; in particular, detection limits were often not specified, and the data tended to be clustered in such a way that sources of exposure variability could not be distinguished. Despite these problems, the data provide new insight into the exposures of nonproduction pulp and paper industry personnel.

Databases, Factual↗
PubMed2002

Biodesulfurization of naphthothiophene and benzothiophene through selective cleavage of carbon-sulfur bonds by Rhodococcus sp. strain WU-K2R.

Naphtho[2,1-b]thiophene (NTH) is an asymmetric structural isomer of dibenzothiophene (DBT), and in addition to DBT derivatives, NTH derivatives can also be detected in diesel oil following hydrodesulfurization treatment. Rhodococcus sp. strain WU-K2R was newly isolated from soil for its ability to grow in a medium with NTH as the sole source of sulfur, and growing cells of WU-K2R degraded 0.27 mM NTH within 7 days. WU-K2R could also grow in the medium with NTH sulfone, benzothiophene (BTH), 3-methyl-BTH, or 5-methyl-BTH as the sole source of sulfur but could not utilize DBT, DBT sulfone, or 4,6-dimethyl-DBT. On the other hand, WU-K2R did not utilize NTH or BTH as the sole source of carbon. By gas chromatography-mass spectrometry analysis, desulfurized NTH metabolites were identified as NTH sulfone, 2'-hydroxynaphthylethene, and naphtho[2,1-b]furan. Moreover, since desulfurized BTH metabolites were identified as BTH sulfone, benzo[c][1,2]oxathiin S-oxide, benzo[c][1,2]oxathiin S,S-dioxide, o-hydroxystyrene, 2-(2'-hydroxyphenyl)ethan-1-al, and benzofuran, it was concluded that WU-K2R desulfurized NTH and BTH through the sulfur-specific degradation pathways with the selective cleavage of carbon-sulfur bonds. Therefore, Rhodococcus sp. strain WU-K2R, which could preferentially desulfurize asymmetric heterocyclic sulfur compounds such as NTH and BTH through the sulfur-specific degradation pathways, is a unique desulfurizing biocatalyst showing properties different from those of DBT-desulfurizing bacteria.

Carbon↗
PubMed1999

The effect of nitrogen oxide level modulation on the content of thiol compounds and anaerobic sulfur metabolism in mice brains.

Aminoguanidine (AG) an inhibitor of NO-synthase reduces cysteine (Cys), cystine (CC), sulfane sulfur (SS) and glutathione (GSH) in brain stems but practically has no effects on the levels of reactive oxygen species (ROS). In cortex AG decreases to a lower degree the concentration of Cys, CC, GSH but in this brain part significantly decreases ROS levels and increases SS. Under the AG action cystathionase (CST) activity very seriously decreases in stems and in cortex and simultaneously activity of 3-mercaptopyruvate sulfurtransferase (MPST) increases. The morpholinosydnonimine (SIN-1) the specific donor of NO and O2 only slightly reduces Cys and GSH in brain stems and ROS and SS remain at the control levels. Simultaneously, there is an increase in cortex of the amounts of GSH with the reduction of ROS and SS. Furthermore, SIN-1 seriously decreases in stems and cortex the activity of CST and increases the activity of MPST. These results confirmed the relationship between intracellular levels of NO, sulfhydryl groups, ROS, and anaerobic sulfur metabolism.

Anaerobiosis↗
PubMed2001

Regional characteristics of sulfur and lead isotope ratios in the atmosphere at several Chinese urban sites.

Sulfur and lead isotope ratios in the atmosphere were measured at several selected sites (Harbin, Changchun, Dalian, Waliguan, Shanghai, Nanjing, Guiyang) in China and Tsukuba (Japan), to reveal regional sources characteristics over Eastern Asia. Average S isotope ratios for SO2 and sulfate in the atmosphere in China were close to those of the coals used in each region, indicating a considerable contribution of coal combustion to the sulfur compounds in the atmosphere. Most northern cities had around 5% sulfur isotope ratio, while Guiyang, a southwestern city in China, showed a considerably lower sulfur isotope ratio (about -3%) because of the unusually light sulfur isotope ratio of coals in this region. These were considerably different from the value (-1.4%) for Tsukuba (Japan). Lead isotope ratios also suggested that coal combustion considerably contributed to atmospheric lead in some cases in China. At the same time, influences by the emission of Chinese lead ores were also observed in northern cities. Seasonal variations of both sulfur and lead isotope ratios indicated the existence of a certain amount of industrial sources other than coal combustion. In addition, fractionation effect between SO2 and sulfate showed a seasonal tendency (high in winter (0-6%) and low in summer (-1-3%)), suggesting the oxidation pathway of SO2 changed seasonally.

Air Pollution↗
PubMed2001

Enzymology and molecular biology of prokaryotic sulfite oxidation.

Despite its toxicity, sulfite plays a key role in oxidative sulfur metabolism and there are even some microorganisms which can use it as sole electron source. Sulfite is the main intermediate in the oxidation of sulfur compounds to sulfate, the major product of most dissimilatory sulfur-oxidizing prokaryotes. Two pathways of sulfite oxidation are known: (1) direct oxidation to sulfate catalyzed by a sulfite:acceptor oxidoreductase, which is thought to be a molybdenum-containing enzyme; (2) indirect oxidation under the involvement of the enzymes adenylylsulfate (APS) reductase and ATP sulfurylase and/or adenylylsulfate:phosphate adenylyltransferase with APS as an intermediate. The latter pathway allows substrate phosphorylation and occurs in the bacterial cytoplasm. Direct oxidation appears to have a wider distribution; however, a redundancy of pathways has been described for diverse photo- or chemotrophic, sulfite-oxidizing prokaryotes. In many pro- and also eukaryotes sulfite is formed as a degradative product from molecules containing sulfur as a heteroatom. In these organisms detoxification of sulfite is generally achieved by direct oxidation to sulfate.

Amino Acid Sequence↗
PubMed1985

Transpositional Mutagenesis of Thiobacillus novellus and Thiobacillus versutus.

Transpositional mutagenesis of Thiobacillus novellus by Tn501 was achieved by means of the incompatibility of IncP plasmids. Tn501 insertion caused three types of mutant phenotypes: isoleucine auxotrophy, lysine auxotrophy, and a reduced ability to oxidize reduced sulfur compounds and to fix CO(2). Oxidation rates for elemental sulfur (S), thiosulfate (S(2)O(3)), and tetrathionate (S(4)O(6)) in mutants of the latter type were reduced relative to those of the nonmutant control strain. Incorporation of labeled bicarbonate (HCO(3)) was also significantly impaired. Although suicide vehicles were not useful for the introduction of transposons into T. novellus, this method was effective for the Tn1721-induced mutagenesis of Thiobacillus versutus. Tn1721 insertions resulted in the loss of the natural resistance of T. versutus to arsenate and gentamicin and in auxotrophies for isoleucine-valine, arginine, phenylalanine, valine, and panthothenate. Transpositional mutagenesis by either method should prove to be a useful tool for further study of these and other members of the genus Thiobacillus.

Journal Article↗
PubMed1991

[Correlation between odor thresholds and saturated vapor pressures of odorants].

The purpose of our work is to develop an estimation method for odor thresholds on the basis of physicochemical properties of odorous compounds. In this report, we examined the correlation between odor thresholds (Cth) and the saturated vapor pressures (Pvp) of various odorants. Results. 1) There were very good correlations between Pvp and k. k represents an indicator of lipid affinity. In our earlier report, k was obtained by the analysis of the gas chromatography with a column packed with a support coated by a phospholipid. Accordingly the correlations show that Pvp may be an indicator of solubility into the lipid phase. 2) It was found that correlations between Pvp and Cth were very good in several homologous series of aliphatic compounds. However ionized substances, such as acids and amines, and sulfur compounds had no good correlations. 3) In odorants having more than 3-5 carbon atoms, odor thresholds of normal types were higher than those of iso types. 4) In the series of amines, the relationship between Cth and Pvp depended upon the length and the number of alkyl chains combined with the contained nitrogen atom. 5) In the series of alcohol and aldehyde, the decrease of Cth in the rate became smaller with the decrease of Pvp.

Air Pollutants↗
PubMed2002

Effect of wild strains of Lactococcus lactis on the volatile profile and the sensory characteristics of ewes' raw milk cheese.

The production of volatile compounds by wild strains of Lactococcus lactis used as starter cultures and their effect on the sensory characteristics of ewes' raw milk cheese were investigated. Sixteen vats of cheese were manufactured and ripened for 120 d in two experiments, each of them duplicated. In the first experiment, milk was inoculated with different ratios of four wild Lactococcus lactis strains, two producing and two not producing branched-chain volatile compounds, and in the second experiment with different ratios of a commercial starter culture and the two strains producing branched-chain volatile compounds. Cheese pH, proteolysis, and aminopeptidase activity increased when the strains producing branched-chain volatile compounds were inoculated at a higher rate. Fifty volatile compounds were identified in cheeses using a purge and trap system coupled to a gas chromatography-mass spectrometry apparatus. The relative abundances of 30 volatile compounds (8 alcohols, 5 aldehydes, 3 ketones, 12 esters, 1 sulfur compound, and 1 benzenic compound) were influenced by starter culture composition. 2-Methylpropanol, 3-methylbutanol, isobutyl acetate, isoamyl acetate, ethyl butyrate, isobutyl butyrate, and isoamyl butyrate were always more abundant in the cheeses made with a higher level of L. lactis strains producing branched-chain volatile compounds. Flavor intensity was enhanced by a high level of L. lactis strains producing branched-chain volatile compounds in the first experiment, in which four wild L. lactis strains were used as starter culture, but not in the second experiment, in which a combination of two wild L. lactis strains and the commercial starter culture were used. Flavor quality, as judged by trained panelists, was impaired in both experiments by a high level of L. lactis strains producing branched-chain volatile compounds.

Aminopeptidases↗