Presence Of Dimethyl Sulphoxide Research Articles

Effects of indirect actions and oxygen on relative biological effectiveness: estimate of DSB inductions and conversions induced by therapeutic proton beams

Purpose: This study evaluated the DNA double strand breaks (DSBs) induced by indirect actions and its misrepairs to estimate the relative biological effectiveness (RBE) of proton beams.Materials and methods: From experimental data, DSB induction was evaluated in cells irradiated by 62 MeV proton beams in the presence of dimethylsulphoxide (DMSO) and under hypoxic conditions. The DNA damage yields for calculating the RBE were estimated using Monte Carlo Damage Simulation (MCDS) software. The repair outcomes (correct repairs, mutations and DSB conversions) were estimated using Monte Carlo Excision Repair (MCER) simulations.Results: The values for RBE of 62 MeV protons (LET = 1.051 keV/μm) for DSB induction and enzymatic DSB under aerobic condition (21% O2) was 1.02 and 0.94, respectively, as comparing to 60Co γ-rays (LET = 2.4 keV/μm). DMSO mitigated the inference of indirect action and reduced DSB induction to a greater extent when damaged by protons rather than γ-rays, resulting in a decreased RBE of 0.86. DMSO also efficiently prevented enzymatic DSB yields triggered by proton irradiation and reduced the RBE to 0.83. However, hypoxia (2% O2) produced a similar level of DSB induction with respect to the protons and γ-rays, with a comparable RBE of 1.02.Conclusions: The RBE values of proton beams estimated from DSB induction and enzymatic DSB decreased by 16% and 12%, respectively, in the presence of DMSO. Our findings indicate that the overall effects of DSB induction and enzymatic DSB could intensify the tumor killing, while alleviate normal tissue damage when indirect actions are effectively interrupted.

Efficiency of mannitol-supplemented medium during adding/removing ovarian tissue with penetrating cryoprotective agents.

Most protocols to cryopreserve ovarian tissue utilize the permeable cryoprotective agents (CPAs) in 1.5M concentration. However the issues related to the ability to use higher concentrations of CPAs have remained open. The research aim was to assess the efficiency of media containing osmotically active sugars (sucrose, mannitol) at stepwise adding/removing of 3M dimethylsulphoxide (DMSO) and propanediol (PROH) on ovarian tissue integrity. After the CPAs adding/removing the ovarian tissue injury was histologically examined, as well as the oocyte volume in tissue structure was assessed. It has been found, that after adding/removing of PROH and DMSO solutions the maximum amount of normal follicles made 67-93% when using Dulbecco's Modified Eagle Medium (DMEM) with 200mM sucrose. Assessment of tissue damage after adding/removing of CPAs has demonstrated that the percentage of normal follicles was 83-87% using DMSO in presence of both sucrose and mannitol as the dilution media components. While removing PROH the level of follicles preservation was 2.5× higher when using mannitol compared with sucrose. Our results indicate that the ovarian tissue injury was minimal during adding 3M CPAs using DMEM, containing sucrose and following application of mannitol at removing both DMSO and PROH.

An efficient synthesis and biological study of substituted 8-chloro-5-methoxy/8-chloro-4H-1,4-benzothiazines, their sulphones and ribofuranosides

8-Chloro-5-methoxy/8-chloro-4H-1,4-benzothiazines were synthesized by condensation followed by oxidative cyclisation of 2-amino-6-chloro-3-methoxy/2-amino-3-chlorobenzenethiol with β–diketones/β–ketoesters in the presence of dimethyl sulphoxide. By treating 4H-1,4-benzothiazines with 30% hydrogen peroxide in glacial acetic acid, 4H-1,4-benzothiazine-1,1-dioxides (sulphones) were synthesized. The 4H-1,4-benzothiazines have also been used as a base to prepare ribofuranosides by the reaction with β–D-ribofuranose-1-acetate-2,3,5-tribenzoate. All the synthesized compounds have been characterized by spectral and elemental analysis and have been examined for antimicrobial and anthelmintic activity. 4H-1,4-benzothiazines, the nitrogen and sulphur containing heterocycles are prepared by condensation followed by oxidative cyclization of 2-aminobenzenethiols with β-diketones/β-ketoester in dimethylsulphoxide. These compounds were then used as base to prepare ribofuranosides and their sulphones.

Symmetrical and unsymmetrical Brønsted acidic ionic liquids for the effective conversion of fructose to 5-hydroxymethyl furfural

Symmetrical and unsymmetrical Bronsted acidic Ionic Liquids (ILs) have been synthesized via a one-pot halogen-free route and characterized by TGA-DTA and DSC to compare their stability and activity. The acidities of the four ILs have also been tested by the Hammett method. These ILs were utilised as catalysts for the dehydration of fructose to 5-hydroxymethylfurfural (HMF) in the presence of dimethylsulphoxide (DMSO) as solvent. The effects of reaction time, temperature and catalyst concentration were studied. The ILs are very efficient for the reaction at relatively lower temperature with very good HMF yield and selectivities. The used ILs could be easily recycled without any significant loss in fructose conversion and HMF yield.

Development of a cryopreservation protocol for testicular interstitial cells with the account of temperature intervals for controlled cooling below −60 °С

A long course of anticancer therapy may lead to testicular steroidogenesis destruction. Cryopreservation of testicular interstitial cells (TIC) would be a strategy to protect hormonal and fertile potential of pre-pubertal boys treated with chemo – or radiotherapy. The aim of this research was to optimize protocols for freezing of TIC. Essential physical processes associated with the presence of dimethyl sulphoxide (Me 2SO) in the cryoprotectant solution take place at the temperatures below −60 °С. These processes are the eutectic crystallization at the stage of freezing and the recrystallization before the melting of the eutectic mixture at the stage of heating. Both of the processes affect the viability of the cells subjected to cryopreservation. Temperature intervals when these processes take place were determined by the method of thermoplastic deformation for 10% Me 2SO selected for cryopreservation of TIC. Rat TIC were cryopreserved using five different protocols which varied in cooling rates within the chosen temperature intervals. Post-thaw cell viability and metabolic activity were evaluated by Trypan Blue and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) staining assays. Leydig cell recovery after cryopreservation was measured by 3-beta-hydroxysteroid dehydrogenase reaction. Based on the obtained results, the authors developed a cryopreservation protocol for TIC which makes it possible to achieve great cell viability due to using controlled cooling rates within the temperature intervals below −60 °С.

Whole sheep ovary cryopreservation: evaluation of a slow freezing protocol with dimethylsulphoxide

To evaluate a slow freezing method for whole ovary cryopreservation by evaluating effects of added cryoprotectant. Sheep ovaries were isolated during surgery, flushed with either Ringer-Acetate or dimethylsulphoxide and cryopreserved by slow freezing. After rapid thawing, viability was assessed by ovarian in vitro perfusion, cell culture, histology and fluorescent live-dead assay. Production of cyclic AMP and progesterone was slightly higher in the dimethylsulphoxide group. Cultured ovarian cells from dimethylsulphoxide-preserved ovaries secreted larger amounts of progesterone than cells from Ringer-Acetate preserved. Light microscopy of ovarian biopsies obtained after perfusion, revealed well-preserved tissue in the dimethysulphoxide group but not in the Ringer-Acetate group. The density of small follicles and ovarian cell viability were higher in dimethysulphoxide ovaries compared to Ringer-Acetate ovaries. Equilibrium with its protective effect can be achieved by slow freezing protocol, with an additional protective effect by the presence of dimethylsulphoxide.

ChemInform Abstract: Synthesis of Grevillins, Novel Pyrandione Pigments of Fungi. Biogenetic Interrelationships Between Grevillins, Pulvinic Acids, Terphenylquinones and Xylerythrins.

A synthesis of the grevillin group of pyrandione pigments e.g.3, 23 and 24 present in fungi is described. The synthesis, which is based on a biogenetic model, uses bis-benzylacyloins 9 and their corresponding oxalate derivatives as key intermediates (Scheme 3). Treatment of the grevillins 25–c with sodium ethoxide in ethanol effects their quantitative isomerisation into the corresponding terphenylquinone pigments 4a–c. Perkin-type condensations between the terphenylquinones 4 and arylacetic acids in the presence of sodium acetate–acetic anhydride then produces the xylerythrin pigments 29a–e, whereas rearrangements of 4 in the presence of dimethyl sulphoxide leads to pulvinic acid derivatives, e.g.31, 32 and 5. These synthetic studies interrelate the biosynthetic origins of the pigment types 3, 4, 5 and 8 together with the related pulvinone 6 and furanone 7 fungal pigments.

Tabular silver halide crystals prepared by controlled Ostwald growth in the presence of dimethyl sulphoxide

AbstractThe results of research in the size and shape of silver bromide crystals precipitated by the Ostwald controlled growth method at the presence of dimethyl sulphoxide were presented in the paper. The silver bromide crystals were produced in the form of microcrystal suspension stabilised by gelatine. In the course of the synthesis of crystals, the constant concentration of dimethyl sulphoxide, concentration of excessive bromide ions and the constant ionic strength were achieved. The tabular crystals of silver bromide with their average size of 50 μm and their aspect ratio equal to 100 were obtained by means of this method. The suspensions of flat silver bromide crystals produced in this manner can be used in the production of high‐sensitivity materials. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Facile Synthesis of Nitriles from Aromatic Aldehydes Using DMSO‐I2

Nitriles have been prepared from different aromatic aldehydes by a one‐pot process using hydroxylamine hydrocloride and molecular iodine in the presence of dimethylsulphoxide.

Lipid-soluble smoke particles damage endothelial cells and reduce endothelium-dependent dilatation in rat and man

BackgroundCigarette smoking is a strong risk factor for vascular disease and known to cause dysfunction of the endothelium. However, the molecular mechanisms involved are still not fully understood.MethodsIn order to reveal the direct effects of lipid-soluble smoke particles on the endothelium, ring segments isolated from rat mesenteric arteries and human middle cerebral arteries (MCA) obtained at autopsy were incubated for 6 to 48 hrs in the presence of dimethylsulphoxide (DMSO)-soluble particles from cigarette smoke (DSP), i.e. lipid-soluble smoke particles. The endothelial microstructure was examined by transmission electron microscopy. The endothelial function was evaluated by acetylcholine (ACh)-induced endothelium-dependent vasodilatation, using a sensitive myograph.ResultsAfter DSP treatment, the arterial endothelium was swollen and loosing its attachment. In functional tests, the total ACh-induced dilatation, the nitric oxide (NO)-mediated and the endothelium-derived hyperpolarization factor (EDHF)-mediated dilatations were significantly decreased by DSP in a time- and concentration-dependent manner (p < 0.05). Nicotine, an important compound in cigarette smoke had, in an equivalent concentration as in DSP, no such effects (p > 0.05). Similar results were obtained in the human MCA.ConclusionThus, we demonstrate that the lipid-soluble smoke particles, but not nicotine, caused damage to arterial endothelium and reduced the endothelium-dependent dilatation in man and rat.

Effect of dimethyl sulphoxide on the crystal structure of porcine pepsin

The structure of porcine pepsin crystallized in the presence of dimethyl sulphoxide has been analysed by X-ray crystallography to obtain insights into the structural events that occur at the onset of chemical denaturation of proteins. The results show that one dimethyl sulphoxide molecule occupies a site on the surface of pepsin interacting with two of its residues. An increase in the average temperature factor of pepsin in the presence of dimethyl sulphoxide has been observed indicating protein destabilization induced by the denaturant. Significant increase in the temperature factor and weakening of the electron density have been observed for the catalytic water molecule located between the active aspartates. The conformation of pepsin remains unchanged in the crystal structure. However, the enzyme assay and circular dichroism studies indicate that dimethyl sulphoxide causes a slight change in the secondary structure and complete loss of activity of pepsin in solution.

Spectrophotometric flow-injection determination of sulphate in soil solutions

A flow-injection procedure for spectrophotometric determination of sulphate in soil solutions is proposed. Samples are directly soaked from the soils under field conditions, in-line filtered through ceramic plates, and preserved with thymol. The method involves reaction with barium dimethylsulphonazo(III) (DMSA) in the presence of dimethylsulphoxide (DMSO) with further measuring the decrease in absorbance at 668 nm. A linear response is observed up to about 5 mgl −1 SO 4, and detection limit (3 σ criterion) is 0.1 mg l −1 SO 4. Only 4.5 μg DMSA is consumed per determination. The system is rugged and baseline drift is not observed during extended operation periods. About 60 samples are injected per hour, and the results are precise (r.s.d. <2%) and in agreement with ion chromatography.

Preparation and characterisation of immobilised metal ion hollow-fibre polysulphone membranes. Their application in high-speed pectic enzyme fractionation

Chelating hollow-fibre membranes were prepared from epoxy-activated polysulphone microfiltration fibres by introducing iminodiacetic acid (IDA) groups in the presence of dimethyl sulphoxide. Fibres with 160, 350 and 620 μmol epoxy groups/ml provided ligand densities of 69, 134 and 203 μmol IDA/ml and pure water fluxes of 7.8, 5.8 and 0.42 cm/min, respectively. However, lysozyme capacity was close to 4 μmol/ml for all fibres. Adsorption isotherms for lysozyme and pectinesterase did not fit Langmuir-type curves and the existence of two types of ligand (A and B) with different accessibility to proteins was assumed. For pectinesterase, maximum capacities of 5100 and 2900 U/ml and dissociation constants of 25 and 316 U/ml were found, respectively, for ligands A and B. For lysozyme, maximum capacities were 2.9 and 0.9 μmol/ml and dissociation constants 5.0 and 102 μM, respectively, for said ligands. A cartridge assembled with IDA hollow fibres had a dynamic capacity for pectinesterase of 7509 U/ml. Productivity of this cartridge for pectic enzyme fractionation was 750 pectinesterase U/ml min, far higher than that obtained with a chelating soft gel (81 pectinesterase U/ml min).

The effect of dimethyl sulphoxide on the induction and repair of double-strand breaks in human cells after irradiation with gamma-rays and accelerated ions: rapid or slow repair may depend on accessibility of breaks in chromatin of different compactness

Purpose : The repair of double-strand breaks (dsb) in mammalian cells is characterized by a rapid phase with a half-life of less than half an hour and a slower phase that lasts for many hours. The proportion of slow repair increase with LET and it has been suggested that the slow repair component consists of more complex damage and is more deleterious to the cells. To see if removal of OH radicals could remove part of the damage in complex dsb and make them easier to repair, human cells were irradiated in the presence of dimethyl sulphoxide (DMSO). Methods : Induction and repair of dsb were studied by neutral elution in human VH10 cells exposed to gamma-rays, helium ions (mean LET 40 keV/mum) and 80 and 125 keV/mum monoenergetic nitrogen ions in the presence and absence of 2M DMSO. Results : Incubation of cells exposed to gamma-rays, 40 keV/mum helium and 80 keV/mum N ions demonstrated that scavenging of OH radicals by DMSO removed most of the rapid repair component. The response to DMSO was less marked after 125 keV/mum nitrogen ions, where about half of the rapid repair was resistant to DMSO. Conclusions : It is unlikely that the complexity of dsb is responsible for the slow repair because the removal of OH radicals did not make the breaks easier to repair. Instead, it is suggested that rapid and slow repair can be explained on the basis of how different parts of the chromatin are accessible to repair enzymes.

Water and DMSO membrane permeability characteristics of in-vivo- and in-vitro-derived and cultured murine oocytes and embryos.

Although embryo cryopreservation is routine for many mammalian species, it is important to know how the fundamental cryobiology of these cells changes with development. Progressive cleavage divisions result in a reduction in the blastomere surface area available for water and cryoprotectant mass transport. Therefore, the membrane permeability of murine oocytes, zygotes, 2-cell, 4-cell, and 8-cell embryos to water (Lp), and dimethylsulphoxide (PDMSO), and the reflection coefficient, sigma (sigma) were determined. Oocytes or zygotes were recovered, cumulus cells removed, then cultured until use. Oocytes and embryos were immobilized and perfused with treatment solutions at 24 degrees C. Osmotically induced cell volume changes over time were videotaped followed by image analysis. The Lp values in the presence of dimethylsulphoxide (DMSO) were 0.77, 0.81, 0.94, 0.86, and 1.10 microm/min/atm, and the PDMSO values were 1.85, 2.04, 2.41, 1.95, and 1.25x10(-3) cm/min for oocytes, zygotes, 2, 4, and 8-cell embryos respectively. The Lp values in the presence of DMSO were significantly (P < 0.05) higher than those in the absence of DMSO. Treating the whole embryo as a single osmotic entity leads to significantly (P < 0.05) elevated PDMSO estimates relative to those based upon measurements of individual blastomeres. These data indicate that both Lp and PDMSO estimates are lower when predicted on an individual blastomere basis. The data also show that neither Lp nor PDMSO differ among oocytes, zygotes, 2-cell and 4-cell embryos. However, the significantly higher Lp and lower PDMSO of the 8-cell stage support the hypothesis that fundamental cryobiological differences may require developmental stage-specific embryo cryopreservation protocols.

Influence of acetonitrile, dimethylsulphoxide and lead on the electro-oxidation of small organic molecules: an on-line mass spectroscopy study

The electro-oxidation of HCOOH in 0.05 M H 2SO 4 was investigated in an electrolyte containing Pb 2+ or acetonitrile. The catalytic effect caused by the simultaneous presence of lead and acetonitrile is higher than that of acetonitrile or lead alone. The influence of acetonitrile on the electro-oxidation of formamide and dimethylformamide at a painted Pt electrode in 0.05 M H 2SO 4 was also investigated. At potentials below 0.6 V / RHE the oxidation of formamide is catalysed by the presence of acetonitrile in the electrolyte; however, the electro-oxidation of dimethylformamide is inhibited under these conditions. The electro-oxidation of HCOOH was also investigated in the presence of dimethylsulphoxide (DMSO). It was found that DMSO inhibits the oxidation of formic acid. The addition of Pb 2+ to the DMSO-containing electrolyte is able to compensate for the inhibitory effect of DMSO. Nevertheless, the original catalytic effect of lead is not obtained in the presence of DMSO. In contrast with formic acid, the electro-oxidation of methanol at a painted Pt electrode in an electrolyte containing 0.05 M H 2SO 4 + 0.1 M CH 3OH is inhibited by the presence of acetonitrile. Furthermore, the inhibitory effect of the same concentration of DMSO is stronger than that of acetonitrile.

Effect of carbon sources and electron acceptors in the growth medium of Proteus spp. on the formation of (R)-2-hydroxycarboxylate viologen oxidoreductase and dimethylsulphoxide reductase

Proteus vulgaris and P. mirabilis were grown anaerobically on glucose in the absence or presence of dimethylsulphoxide (DMSO) as electron acceptor or on (S)- or (RS)-lactate in the presence of nitrogen (N)-oxides, sulphur (S)-oxides or pyruvate. During growth on glucose the main fermentation product was ethanol and in the presence of DMSO it was (R)-lactate. Growth on (RS)-lactate led to acetate and (R)-lactate and growth on (S)-lactate produced almost only acetate. Depending on the growth medium, in crude extracts of P. vulgaris the activities of (R)-2-hydroxycarboxylate viologen oxidoreductase (HVOR), measured as (R)-lactate dehydrogenase, and DMSO reductase were 0.5–8.0 and 0.3–1.1 units (U)/mg protein, respectively. Addition of nitrate to the growth medium diminished both enzyme activities to <0.1 U/mg protein. P. mirabilis showed also high HVOR activity when grown on (RS)-lactate in the presence of DMSO. Also, Clostridium homopropionicum contained 1.8 U/mg of a pyridine-nucleotide-independent reversible (R)-lactate dehydrogenase when tested with the electron acceptor 1,1′-carbomoylmethylviologen (NH2CO-MV). None of the organisms studied were significantly active with (S)-lactate and NH2CO-MV. The possible physiological role of the HVOR may be as a dissimilatory (R)-lactate dehydrogenase.

Primary culture of rat hepatocytes in the presence of dimethyl sulphoxide: A system to investigate the regulation of cytochrome P450 IA

Primary cultures of adult rat hepatocytes would provide a suitable system for the study of hepatic drug metabolism/toxicity provided that the drug-metabolizing enzymes could be maintained at levels approaching those seen in vivo. It has been reported that culture of adult rat hepatocytes in the presence of 2% (v/v) dimethyl sulphoxide (DMSO) allowed partial maintenance of total cytochrome P450 content. However, the levels of the individual isozymes were not determined. Culture of rat hepatocytes in the presence of DMSO did maintain the total cytochrome P450 content at 65% of the fresh cell value after 7 days of culture. This was accompanied by high cytochrome P420 levels suggesting that the solvent was stimulating de novo synthesis rather than maintaining existing enzyme. In the presence of DMSO the level of ethoxyresorufin-O-deethylase (EROD) rose 4-fold in culture, whilst that of pentoxyresorufin- O-dealkylase fell rapidly indicating that the isozyme pattern was altered significantly. The increases in total cytochrome P450 content and EROD activity were prevented by cycloheximide confirming that de novo protein synthesis was occurring. Haem oxygenase activity was significantly reduced and aminolaevulinic acid synthetase was significantly increased in the presence of solvent, suggesting increased haem availability for incorporation into cytochrome P450. However increased haem availability is insufficient in explaining the isozyme specificity of cytochrome P450 induction. Hepatocytes cultured in the presence of 2% (v/v) DMSO were markedly more responsive to 1,2-benzanthracene, with EROD increasing approximately 40-fold.

Isoenzyme-specific induction of cytochromes P-450 in rat hepatocytes cultured in the presence of dimethylsulphoxide

Isoenzyme-specific induction of cytochromes <i>P</i>-450 in rat hepatocytes cultured in the presence of dimethylsulphoxide

Enhanced invasiveness and metastatic potential of epithelial cell lines cultured in the presence of dimethyl sulphoxide

Several passage cycles of poorly metastatic malignant epithelial cells through immunosuppressed mice failed to induce enhanced metastasis-forming ability of cells derived from either the primary subcutaneous tumours or the resultant lung metastases. In vitro treatment of cultured malignant cells with dimethyl sulphoxide (DMSO) induced a reversible change in phenotype towards increased invasiveness but did not significantly increase metastasis formation. A cloned-cell line from a spontaneous in vitro transformant in the presence of DMSO was highly invasive and highly metastatic. In vitro treatment of cultured cells with 2% (v/v) DMSO produced alterations in morphology with decreased growth rate of all cell lines and decreased anchorage-independent colony formation in several malignant cell lines. All in vitro and in vivo effects were reversible following both short- and long-term (1 year) culture of cells in the presence of DMSO, suggesting epigenetic effects. These data support the concept of independent genetic controls for the invasiveness of tumours and the ability to form metastases.