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PubMed2002

Evaluation of the cholinomimetic actions of trimethylsulfonium, a compound present in the midgut gland of the sea hare Aplysia brasiliana (Gastropoda, Opisthobranchia).

Trimethylsulfonium, a compound present in the midgut gland of the sea hare Aplysia brasiliana, negatively modulates vagal response, indicating a probable ability to inhibit cholinergic responses. In the present study, the pharmacological profile of trimethylsulfonium was characterized on muscarinic and nicotinic acetylcholine receptors. In rat jejunum the contractile response induced by trimethylsulfonium (pD2 = 2.46 +/- 0.12 and maximal response = 2.14 +/- 0.32 g) was not antagonized competitively by atropine. The maximal response (Emax) to trimethylsulfonium was diminished in the presence of increasing doses of atropine (P<0.05), suggesting that trimethylsulfonium-induced contraction was not related to muscarinic stimulation, but might be caused by acetylcholine release due to presynaptic stimulation. Trimethylsulfonium displaced [3H]-quinuclidinyl benzilate from rat cortex membranes with a low affinity (Ki = 0.5 mM). Furthermore, it caused contraction of frog rectus abdominis muscles (pD2 = 2.70 +/- 0.06 and Emax = 4.16 +/- 0.9 g), which was competitively antagonized by d-tubocurarine (1, 3 or 10 microM) with a pA2 of 5.79, suggesting a positive interaction with nicotinic receptors. In fact, trimethylsulfonium displaced [3H]-nicotine from rat diaphragm muscle membranes with a Ki of 27.1 microM. These results suggest that trimethylsulfonium acts as an agonist on nicotinic receptors, and thus contracts frog skeletal rectus abdominis muscle and rat jejunum smooth muscle via stimulation of postjunctional and neuronal prejunctional nicotinic cholinoreceptors, respectively.

Animals↗
PubMed2003

Silicibacter pomeroyi sp. nov. and Roseovarius nubinhibens sp. nov., dimethylsulfoniopropionate-demethylating bacteria from marine environments.

Three Gram-negative, rod-shaped, aerobic bacteria that were capable of degrading dimethylsulfoniopropionate (DMSP) were isolated from marine waters. These isolates (DSS-3(T), DSS-10 and ISM(T)) exhibited the ability to demethylate and cleave DMSP, as well as to degrade other sulfur compounds related to DMSP that are cycled in marine environments. Intracellular poly-beta-hydroxybutyrate inclusions, surface blebs and one polar, complex flagellum that rotated exclusively in the clockwise direction were observed for DSS-3(T). The outer membrane of ISM(T) was separated from the cytoplasm at the poles in a toga-like morphology. The primary fatty acid in both strains was C(18 : 1)omega7c. DNA G+C contents for the isolates were 68.0+/-0.1, 68.1+/-0.1 and 66.0+/-0.2 mol% for DSS-3(T), DSS-10 and ISM(T), respectively. 16S rRNA gene sequence analyses placed these organisms within the Roseobacter lineage of the alpha-PROTEOBACTERIA: Closely related species were Silicibacter lacuscaerulensis and Ruegeria atlantica (DSS-3(T) and DSS-10) and Roseovarius tolerans (ISM(T)). Neither DSS-3(T) nor ISM(T) exhibited 16S rRNA similarity >97 % or DNA-DNA hybridization values >45 % to their nearest described relatives. Genotypic and phenotypic analyses support the creation of two novel species: Silicibacter pomeroyi sp. nov. with strain DSS-3(T) (=ATCC 700808(T)=DSM 15171(T)) as the type strain, and Roseovarius nubinhibens sp. nov. with strain ISM(T) (=ATCC BAA-591(T)=DSM 15170(T)) as the type strain.

Base Composition↗
PubMed1993

Suppression of IgE production by IPD-1151T (suplatast tosilate), a new dimethylsulfonium agent: (1). Regulation of murine IgE response.

The effect of IPD-1151T, a new dimethylsulfonium compound, on the IgE response was investigated in the mouse system. The oral administration of IPD-1151T to immunized BALB/c mice suppressed the primary IgE antibody response and depressed the elevation of serum IgE levels, whereas the same treatment did not affect the IgG antibody response. The enhanced expression of low-affinity IgE receptor (Fc epsilon RII/CD23) on the spleen cells of immunized mice was also inhibited by IPD-1151T administration. It was further demonstrated from the adoptive transfer experiment that IPD-1151T, administered to hapten-primed B cell donors, but not to carrier-primed T cell donors, exerted its suppressive influence on the hapten-specific secondary IgE antibody response in irradiated syngeneic recipients. Interestingly, IPD-1151T concentration-dependently inhibited the production of interleukin 4 (IL-4) by D10G4.1, known to be a typical Th2 clone. However, IPD-1151T did not suppress the production of IgE and IgG1 by normal splenic B cells stimulated with lipopolysaccharide and IL-4. Moreover, IL-4-induced expression of Fc epsilon RII on normal spleen cells was not inhibited by the agent. These results strongly suggest that the IgE-suppressive activity of IPD-1151T is most likely due to the inhibition of IL-4 production at the T cell level.

Administration, Oral↗
PubMed1999

Transformation of sulfur compounds by an abundant lineage of marine bacteria in the alpha-subclass of the class Proteobacteria.

Members of a group of marine bacteria that is numerically important in coastal seawater and sediments were characterized with respect to their ability to transform organic and inorganic sulfur compounds. Fifteen strains representing the Roseobacter group (a phylogenetic cluster of marine bacteria in the alpha-subclass of the class Proteobacteria) were isolated from seawater, primarily from the southeastern United States. Although more than one-half of the isolates were obtained without any selection for sulfur metabolism, all of the isolates were able to degrade the sulfur-containing osmolyte dimethyl sulfoniopropionate (DMSP) with production of dimethyl sulfide (DMS). Five isolates also degraded DMSP with production of methanethiol, indicating that both cleavage and demethylation pathways for DMSP occurred in the same organism, which is unusual. Five isolates were able to reduce dimethyl sulfoxide to DMS, and several isolates also degraded DMS and methanethiol. Sulfite oxygenase activity and methanesulfonic acid oxygenase activity were also present in some of the isolates. The ability to incorporate the reduced sulfur in DMSP and methanethiol into cellular material was studied with one of the isolates. A group-specific 16S rRNA probe indicated that the relative abundance of uncultured bacteria in the Roseobacter group increased in seawater enriched with DMSP or DMS. Because this group typically accounts for >10% of the 16S ribosomal DNA pool in coastal seawater and sediments of the southern United States, clues about its potential biogeochemical role are of particular interest. Studies of culturable representatives suggested that the group could mediate a number of steps in the cycling of both organic and inorganic forms of sulfur in marine environments.

Alphaproteobacteria↗
PubMed2005

Dimethylsulfoniopropionate turnover is linked to the composition and dynamics of the bacterioplankton assemblage during a microcosm phytoplankton bloom.

Processing of the phytoplankton-derived organic sulfur compound dimethylsulfoniopropionate (DMSP) by bacteria was studied in seawater microcosms in the coastal Gulf of Mexico (Alabama). Modest phytoplankton blooms (peak chlorophyll a [Chl a] concentrations of approximately 2.5 microg liter(-1)) were induced in nutrient-enriched microcosms, while phytoplankton biomass remained low in unamended controls (Chl a concentrations of approximately 0.34 microg liter(-1)). Particulate DMSP concentrations reached 96 nM in the enriched microcosms but remained approximately 14 nM in the controls. Bacterial biomass production increased in parallel with the increase in particulate DMSP, and nutrient limitation bioassays in the initial water showed that enrichment with DMSP or glucose caused a similar stimulation of bacterial growth. Concomitantly, increased bacterial consumption rate constants of dissolved DMSP (up to 20 day(-1)) and dimethylsulfide (DMS) (up to 6.5 day(-1)) were observed. Nevertheless, higher DMSP S assimilation efficiencies and higher contribution of DMSP to bacterial S demand were found in the controls compared to the enriched microcosms. This indicated that marine bacterioplankton may rely more on DMSP as a source of S under oligotrophic conditions than under the senescence phase of phytoplankton blooms. Phylogenetic analysis of the bacterial assemblages in all microcosms showed that the DMSP-rich algal bloom favored the occurrence of various Roseobacter members, flavobacteria (Bacteroidetes phylum), and oligotrophic marine Gammaproteobacteria. Our observations suggest that the composition of the bacterial assemblage and the relative contribution of DMSP to the overall dissolved organic sulfur/organic matter pool control how efficiently bacteria assimilate DMSP S and thereby potentially divert it from DMS production.

Alphaproteobacteria↗
PubMed2006

A photophysical study of terphenyl core oligosulfonimide dendrimers exhibiting high steady-state anisotropy.

The photophysical properties of three dendrimers containing a p-terphenyl core with appended sulfonimide branches of different size and n-octyl chains have been investigated in dichloromethane solution. In the dendrimer absorption spectra contributions from both the branches and the core are clearly identified. The fluorescence spectra show only the characteristic fluorescence of the terphenyl unit. Energy transfer from the appended chromophoric groups to the core does not occur. In the dendrimers, the terphenyl core exhibits a very high fluorescence quantum yield (ca. 0.75) and a short emission lifetime (0.8 ns). These properties allowed investigations of the fluorescence depolarization caused by rotation of the dendrimers. The dendrimers show a very high steady-state anisotropy in dichloromethane solution at room temperature (0.24 for the largest one), compared to that of the parent terphenyl under the same experimental conditions (<0.01) and in rigid matrix (0.33). Both the n-octyl chains and the sulfonimide branches play important roles to slow down the molecular rotation.

Anisotropy↗
PubMed1997

Betaine-aldehyde dehydrogenase from amaranth leaves efficiently catalyzes the NAD-dependent oxidation of dimethylsulfoniopropionaldehyde to dimethylsulfoniopropionate.

Many flowering plants accumulate the compatible osmolyte glycine betaine in response to osmotic stress, in certain cases together with its sulfonium analog 3-dimethylsulfoniopropionate (DMSP). Compared to glycine betaine, this DMSP accumulation appears to be an evolutionary novelty. The final step in the synthesis of glycine betaine and DMSP is oxidation of the corresponding aldehyde, betaine aldehyde or 3-dimethylsulfoniopropionaldehyde (DMSPald). Leaves of amaranth (Amaranthus hypochondriacus L.) accumulate glycine betaine but do not produce detectable amounts of DMSP. These leaves contain a betaine-aldehyde dehydrogenase (BADH) that catalyzes the final step in glycine betaine synthesis. Here we report that this enzyme efficiently catalyzes the oxidation of DMSPald. On the basis of Vmax/Km values, DMSPald is a better substrate for amaranth BADH than betaine aldehyde itself. The kinetic mechanism followed by amaranth BADH at low concentrations of DMSPald is similar to that with betaine aldehyde; as determined from initial velocity, product, dead-end, and substrate inhibition studies, it is a steady-state bi bi with ordered addition of substrates and random release of products. Like betaine aldehyde, DMSPald is inhibitory at high concentrations, at which a slower alternate route of substrate addition takes place. Our results indicate that the evolution of DMSP biosynthesis in flowering plants could have been facile in that it required no new aldehyde dehydrogenase; BADH may simply have been recruited for a novel function.

Aldehyde Oxidoreductases↗
PubMed1996

Reaction of lipids containing hydroxy groups with trimethylsulfonium hydroxide: formation of O-methyl derivatives.

Base-catalyzed transesterification of acyl lipids with trimethylsulfonium hydroxide (TMSH) is an easy and convenient method for the preparation of fatty acid methyl esters (FAME) for gas chromatography (GC) analyses. We have found, however, that lipids containing hydroxy groups are partially converted to the corresponding O-methyl ether derivatives which may interfere with FAME in GC separations. For example, long-chain alcohols are found to be converted to alkyl methyl ethers, rac-1-O-alkylglycerols to the corresponding 2-O- and 3-O-monomethyl ethers, as well as 2,3-di-O-methyl ethers, hydroxy fatty acids to methoxy FAME, and cholesterol to cholesteryl 3 beta-methyl ether. From our results, it is obvious that TMSH derivatization method is not recommended without limitation for lipids containing hydroxy groups; it may be, however, of some diagnostic value for the analysis of such lipids by GC/mass spectrometry.

Alcohols↗
PubMed1991

Chemical synthesis and physiological activity of sulfonium analogues of platelet activating factor.

Phosphatidylsulfocholine (PSC), the sulfonium analogue of phosphatidylcholine (PC), occurs naturally in some diatoms. The replacement of the [formula; see text] group by a [formula; see text] results in an increase in the polar head group size in PSC relative to that of PC, consistent with the observed increase in permeability of PSC bilayers towards urea. It was of interest to see whether replacement of the [formula; see text] group in platelet activating factor (PAF) by an [formula; see text] group leads to any change in platelet aggregation or other physiological activity. Synthesis of the sulfonium analogue of PAF was carried out by suitable modifications of known procedures. The PAF-sulfonium analogue was found to have almost the same platelet aggregating activity as PAF itself, in the concentration range 1-20 microM, but a much lower activity in the range 0.01-1 microM. The analogue had little or no effect on the platelet aggregation activity of PAF when added in the concentration range 0.01-1 microM and had about half the hypotensive activity of PAF towards hypertensive CDF male rats. The sulfonium analogue, however, was much more cytotoxic to HL-60 cells than PAF itself, in the concentration range 0-15 microM; replacement of the acetate group by a benzyl group increased the cytotoxicity to the level of that of the methoxy analogue of PAF. Thus, replacement of the [formula; see text] group by a [formula; see text] group in the polar head group region of PAF results in a relatively small change in its platelet aggregation activity and a decrease in its hypotensive activity, but greatly increases its antitumor activity.

Animals↗
PubMed2000

Effect of Y-24180, a receptor antagonist to platelet-activating factor (PAF), on allergic cutaneous reactions in actively sensitized mice.

OBJECTIVE AND DESIGN: We examined the effect of Y-24180, a potent antagonist to platelet-activating factor (PAF), on allergic cutaneous reactions in actively sensitized mice. MATERIALS: Male BALB/c and BALB/c-nu/nu mice were used. TREATMENT: Y-24180, ketotifen fumarate (ketotifen), and suplatast tosilate (suplatast) were orally administered twice a day for 3 days beginning 2 days before an ovalbumin (OA) challenge. Hydrocortisone 17-butyrate (hydrocortisone) was applied topically to ear surface once a day for 3 days, beginning 2 days before the OA challenge. METHODS: Mice actively sensitized with OA were challenged by intradermally injecting OA into both ears. Ear thickness was measured with a dial thickness gauge. RESULTS: Increase in ear thickness, with peak responses at 1 h (immediate phase reaction, IPR) and 24 h (late phase reaction, LPR) after the challenge, were induced in actively sensitized BALB/c mice. The reactions were not induced in T cell-deficient BALB/c-nu/nu mice. Y-24180 suppressed both the IPR and LPR of BALB/c mice. Although suplatast suppressed the LPR, the IPR was not affected. Ketotifen suppressed the IPR, but not the LPR. Hydrocortisone suppressed both the IPR and LPR of BALB/c mice. Furthermore, Y-24180 in combination with hydrocortisone significantly enhanced the effect of hydrocortisone on both the reactions. CONCLUSIONS: Y-24180 was demonstrated not only to suppress the IPR and LPR, but also to show strong suppressive effects in combination with topical hydrocortisone. Therefore, Y-24180 is expected to contribute to the treatment of inflammatory skin diseases including atopic dermatitis.

Administration, Oral↗
PubMed1998

Tetrahydrofolate serves as a methyl acceptor in the demethylation of dimethylsulfoniopropionate in cell extracts of sulfate-reducing bacteria.

Tetrahydrofolate was shown to function as a methyl acceptor in the anaerobic demethylation of dimethylsulfoniopropionate to methylthiopropionate in cell extracts of the sulfate-reducing bacterium strain WN. Dimethylsulfoniopropionate-dependent activities were 0.56 micromol methyltetrahydrofolate min-1 (mg protein)-1 and were higher than required to explain the growth rate of strain WN on dimethylsulfoniopropionate. The reaction did not require ATP or reductive activation by titanium(III)-nitrilotriacetic acid. Preincubation of the extract under air significantly decreased the activity (35% loss in 3 h). Three other dimethylsulfoniopropionate-demethylating sulfate reducers, Desulfobacterium niacini, Desulfobacterium vacuolatum, and Desulfobacterium strain PM4, had dimethylsulfoniopropionate:tetrahydrofolate methyltransferase activities of 0.16, 0.05, and 0.24 micromol min-1 (mg protein)-1, respectively. No methyltransferase activity to tetrahydrofolate was found with betaine as a substrate, not even in extracts of betaine-grown cells of these sulfate reducers. Dimethylsulfoniopropionate demethylation in cell extracts of strain WN was completely inhibited by 0.5 mM propyl iodide; in the light, the inhibition was far less strong, indicating involvement of a corrinoid-dependent methyltransferase.

Biodegradation, Environmental↗
PubMed2002

Effect of suplatast tosilate, a Th2 cytokine inhibitor, on cough variant asthma.

STUDY OBJECTIVE: Th2 cytokines play an important role in the pathogenesis of asthma. Our study objective was to determine the effect of suplatast tosilate, a Th2 cytokine inhibitor, on patients with cough-variant asthma. METHODS: Twenty patients with cough-variant asthma (CVA) were assigned to a suplatast tosilate (100 mg three times daily) group or a placebo group for 6 weeks in a double-blind randomized study. The cough scores, medication scores, pulmonary function, bronchial hyperresponsiveness to methacholine, cough threshold for capsaicin, percentage of eosinophils and concentrations of eosinophilic cationic protein (ECP) in hypertonic saline-induced (induced) sputum were evaluated. The main outcome measures were capsaicin cough threshold and concentrations of ECP in induced sputum. RESULTS: In the suplatast group, the cough scores and the medication scores decreased significantly over time. The percentage of eosinophils in induced sputum significantly decreased from 53.5+/-5.6% to 13.6+/-2.6%. The cough threshold for capsaicin improved significantly from 2.72+/-3.41 microM to 39.7+/-22.7 microM in the suplatast group. The concentrations of ECP in induced sputum decreased significantly from 435+/-123 microg/l to 56+/-34 microg/l in the suplatast group. The bronchial responsiveness to methacholine changed from 8.45+/-3.43 units to 11.4+/-3.76 units in the suplatast group. CONCLUSIONS: Suplatast improved the cough scores and the cough threshold for capsaicin in patients with CVA without significant side effects, suggesting the effectiveness of suplatast in the treatment of CVA. Suplatast also decreased the percentage of eosinophils and concentrations of ECP in induced sputum, suggesting improvement in eosinophilic inflammation in patients with CVA. Further pharmacodynamic research is needed to explain the precise mechanism.

Adult↗
PubMed2003

Isolation and characterization of ButA, a secondary glycine betaine transport system operating in Tetragenococcus halophila.

Through functional complementation of an Escherichia coli mutant defective in glycine betaine uptake, we identified a single-component glycine betaine transporter from Tetragenococcus halophila, a moderate halophilic lactic acid bacterium. DNA sequence analysis characterized the ButA protein as a member of the betaine choline carnitine transporter (BCCT) family, that includes a variety of previously characterized compatible solute transporters such as OpuD from Bacillus subtilis, EctP and BetP from Corynebacterium glutamicum, and BetL from Listeria monocytogenes. When expressed in the heterologous host E. coli, the permease is specific for glycine betaine and does not transport the other osmoprotectants previously described for T. halophila (i.e. carnitine, choline, dimethylsulfonioacetate, dimethylsulfoniopropionate, and ectoine). In E. coli, statement of ButA is mainly constitutive and maximal uptake activity may result from a weak osmotic induction. This is the first study demonstrating a role for a permease in osmoregulation, and GB uptake, of a lactic acid bacterium.

Acetoin↗
PubMed2000

N-[4-(3-ethoxy-2-hydropropoxy)phenyl] acrylamide selectively induces apoptosis of cerebellar granule cells in vivo and in vitro in rats.

Oral administration of N-[4-(3-ethoxy-2-hydropropoxy)phenyl] acrylamide (EHA) induced selective granule cell destruction in the granular layer of the cerebellar cortex together with neurological signs, such as delayed righting reflex, gait or truncal ataxia, and convulsion. Neuropathologically, it caused multifocal granule cell destruction with nuclear pyknosis and spongiosis of the neuropile in the granular layer. Other neurons, including Purkinje cells, were spared. Ultrastructurally, damaged granule cells showed aggregation of nuclear chromatin and cytoplasmic edema, but cytoplasmic organelles were preserved. The brain uptake index of 14C-labeled EHA was similar to that of H2O. When EHA was added to rat cerebellar tissue cultures, only the granule cells showed nuclear pyknosis, aggregation of nuclear chromatin, and karyorrhexis with cytoplasmic swelling. These granule cells were positive for DNA fragmentation by the TUNEL method. These results suggest that EHA permeates the blood vessel wall and directly affects the cerebellar granule cells, resulting in selective granule cell apoptosis.

Acrylamides↗
PubMed2003

Add-on effects of suplatast tosilate in bronchial asthma patients treated with inhaled corticosteroids.

Th2 cytokines play an important role in the pathogenesis of asthma. In the present study, we investigated the effect of suplatast tosilate, a selective Th2 cytokine inhibitor, on asthma control, in terms of subjective symptoms and pulmonary function in patients treated with inhaled corticosteroids. Thirty-eight patients with bronchial asthma being treated with inhaled corticosteroids were given suplatast tosilate (100 mg three times daily) for 12 weeks, in a multicenter setting. During the study period, other medications were continued. Morning and evening peak expiratory flow, asthma symptoms, blood eosinophil count and serum IgE levels were monitored. Suplatast tosilate treatment was associated with a significant improvement in mean morning peak expiratory flow (from 295 L/min to 348 L/min, P < 0.01) and evening peak expiratory flow (from 313 L/min to 357 L/min, P < 0.01). The mean daily variation in peak expiratory flow was significantly reduced (from 11.6% to 7.3%, P < 0.01) by suplatast tosilate treatment. The greatest improvement in peak expiratory flow was observed in patients whose blood eosinophil counts were decreased by suplatast tosilate treatment. Treatment with suplatast tosilate improved pulmonary function in patients with bronchial asthma. Our results suggest the therapeutic effects observed may occur through suppression of eosinophilic inflammation.

Administration, Inhalation↗
PubMed2003

Effect of suplatast tosilate, an antiallergic selective Th2 cytokine inhibitor, on acute eosinophilic myocarditis: a case report.

We encountered a 44-year-old woman with acute eosinophilic myocarditis that showed positive immunostaining for interleukin-4 in the area of marked infiltration of eosinophils into the myocardium. When prednisolone alone proved ineffective, supplementary treatment with suplatast tosilate, an antiallergic selective Th2 cytokine inhibitor, improved the patient's inflammation, reduced the level of cardiac enzymes, and allowed for a reduction in corticosteroid dosage without any adverse effects.

Acute Disease↗
PubMed2006

Genotoxicity of dental resin polymerization initiators in vitro.

The polymerization initiators for resins cured using visible light usually consist of a photosensitizer, primarily camphorquinone (CQ), and a reducing agent, which is often a tertiary amine (DMPT, DMAEMA), while the initiator used for self-curing resins consists of benzoyl peroxide (BPO) and a tertiary amine (DMPT). The genotoxicities of camphorquinone (CQ), benzoyl peroxide (BPO), dimethyl-para-toluidine (DMPT), 2-dimethylamino-ethyl-methacrylate (DMAEMA), and 1-allyl-2-thiourea (ATU) were examined using the bioluminescent bacterial genotoxicity test. 4-Nitroquinoline-N-oxide (4NQO) was prepared for comparison with these chemicals. Acetone solutions of the five polymerization initiators and 4NQO were prepared. Benzoyl peroxide (BPO), dimethyl-para-toluidine (DMPT), and 1-allyl-2-thiourea (ATU) showed significant genotoxic activity at 24 h in the bioluminescent bacterial genotoxicity test, at concentrations of approximately 5 microM, 4 mM, and 1 mM, respectively. 2-Dimethyloamino-ethyl-methacrylate (DMAEMA) did not have genotoxic activity and CQ had questionable genotoxic activity. In comparison, 4NQO had strong genotoxicity, at 4 microM, roughly the same as that of BPO. Therefore, BPO should be used carefully in clinical dentistry.

4-Nitroquinoline-1-oxide↗