n-Butanol

Project ID

1542

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IRIS

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Dec. 14, 2010, 3:50 p.m.

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Journal Article

Abstract  The effect of particle chemical composition on the counting efficiency of a commercially available n-butanol condensation particle counter (CPC) was theoretically investigated. The activation probability of particles soluble in n-butanol or covered by a soluble coating was determined by Kohler theory, whereas the activation of insoluble particles was determined by heterogeneous nucleation theory. The theoretically predicted counting efficiencies were fit to experimental data to infer the n-butanol microscopic contact angle on insoluble particles or the volume of a soluble layer coating the particle. The calculated microscopic contact angles were found to depend on particle chemical composition, particle diameter, and the CPC saturator-to-condenser temperature difference. The average n-butanol microscopic contact angle on diesel exhaust and CAST soot was determined to be 5-10 degrees, on Emery oil particles close to 0 degrees, on thermally pre-treated tetracontane (C40H82) particles 25 degrees, and on dry sodium chloride particles 15-20 degrees for CPCs operated at a temperature difference of approximately 7 degrees C (low saturation ratios). The counting efficiencies were very sensitive to particle contamination, as determined by the particle generation method and treatment, an effect that could be reproduced by modified Kohler theory. The dependence of the counting efficiency on particle chemical composition was found to be stronger at lower CPC temperature differences. (C) 2010 Elsevier Ltd. All rights reserved.

Journal Article

Abstract  Background: Metabolomic studies have been applied to disease biomarkers selection. With the metabolomic technique, gas chromatography/mass spectrometry (GC/MS), human serum metabolites can be detected and identified. The purpose of this study was to investigate the serum metabolic profile of hepatitis B virus (HBV) infected cirrhosis patients and to detect disease biomarkers. Methods: HBV infected non-cirrhosis male subjects (n=20) and HBV infected cirrhosis male patients (n=20) participated in this experiment. Serum metabolome was detected through chemical derivatization followed by GC/MS. The high-flux metabolomic data were analyzed by stepwise discriminant analysis. Results: Out of the 41 metabolites detected in serum, we selected metabolites, including acetic acid, sorbitol, D-lactic acid, hexanoic acid, 1-naphthalenamine, butanoic acid, phosphoric acid, D-glucitol, and glucose, which in combination with each other could segregate the two groups. The error count was 0% for the non-cirrhosis group and 25% for the cirrhosis group. Conclusions: This technique can be used to select biomarkers for hepatic cirrhosis. Clin Chem Lab Med 2009;47.

Journal Article

Abstract  Alcohols are widely used as industrial solvents. In spite of the fact that ethanol is a human teratogen, there has not been systematic investigation of the potential teratogenic effects of other alcohols, particularly using the inhalation route of exposure, as would be appropriate in assessing occupational and environmental types of experience. As part of a large teratological examination of industrial alcohols, methanol and ethanol were administered by inhalation to groups of approximately 15 pregnant Sprague-Dawley rats. Methanol was administered at 20,000 ppm (20ME), 10,000 ppm (10ME), 5000 ppm (5ME), and 0 ppm (MECO) for 7 hr/day on Days 1-19 of gestation (Days 7-15 for 20ME). Ethanol was administered at 20,000 ppm (20ET), 16,000 ppm (16ET), 10,000 ppm (10ET), and 0 ppm (ETCO) for 7 hr/day on Days 1-19 of gestation. Dams were sacrificed on Day 20 (sperm = Day 0). One-half of the fetuses were examined using the Wilson technique for visceral defects, and the other half were examined for skeletal defects. The highest concentration of methanol (20ME) produced slight maternal toxicity and a high incidence of congenital malformations (p less than 0.001), predominantly extra or rudimentary cervical ribs and urinary or cardiovascular defects. Similar malformations were seen in the 10ME group, but the incidence was not significantly different from controls. No adverse effects were noted in the 5ME group. Dams in the 20ET group were narcotized by the end of exposure, and maternal weight gain and feed intake were decreased during the first week of exposure. The 16ET dams had slightly depressed weight gain (p less than 0.01) during the first week of exposure, but there were no significant effects on feed consumption. There was no definite increase in malformations at any level of ethanol, although the incidence in the 20ET group was of borderline significance.

Journal Article

Abstract  The characteristics of chlorate (ClO(3)(-)) and perchlorate (ClO(4)(-)) formation were studied during the electrolysis of water containing chloride ions (Cl(-)). The experiments were performed using an undivided Pt/Ti plate electrode under different pH conditions (pH 3.6, 5.5, 7.2, 8.0 and 9.0). ClO(3)(-) and ClO(4)(-) were formed during electrolysis in proportion to the Cl(-) concentration. The generation rates of ClO(3)(-) and ClO(4)(-) under acidic conditions (pH 3.6 and 5.5) were lower than in basic pH conditions (pH 7.2, 8.0 and 9.0). However, the pH of the solution did not influence the conversion of ClO(3)(-) to ClO(4)(-). The effects of intermediately formed oxidants on the production of ClO(3)(-) and ClO(4)(-) were observed using sodium thiosulfate (Na(2)S(2)O(3)) as the active chlorine scavenger and tertiary butyl alcohol (t-BuOH) as the hydroxyl radical (OH) scavenger. The results revealed that electrolysis reactions that involved active chlorine contributed dominantly to ClO(3)(-) production. The direct oxidation reaction rate of Cl(-) to ClO(3)(-) was 13%. The OH species that were intermediately formed during electrolysis were also found to significantly affect ClO(3)(-) and ClO(4)(-) production. The key formation pathways of ClO(3)(-) and ClO(4)(-) were studied using kinetic model development.

Journal Article

Abstract  Cyclotrimethylenetrinitramine (RDX) has been used extensively as an explosive. Prior to this study no data were available on the metabolism of RDX in animals. Metabolism of 14C-RDX was studied in male and female miniature pigs after a one-time gavage with 41 to 44 mg/kg, (0.8 to 0.9 mCi/animal) in an aqueous suspension of 0.1% carboxymethyl cellulose. Metabolic profiles and identification of 14C-RDX-derived radioactivity in plasma, liver and urine were performed utilizing HPLC radio-scanning and LC/MS/MS analysis. Analytical standards were available for all proposed metabolites. Two HPLC columns with differing elution profiles were used for separation, quantification and tentative identification. Identifications were confirmed using LC/MS/MS. Two metabolites were isolated and identified as 4-nitro-2, 4-diazabutanal and a novel metabolite, 4-nitro- 2-4 diaza-butanamide. Analysis also revealed trace levels of 1-nitroso-3,5-dinitro-1,3,5-triazacyclohexane (MNX), 1,3-dintroso-5-nitro-1,3,5-triazacyclohexane (DNX) and 1,3,5-trinitroso- 1,3,5-triazacyclohexane (TNX) in plasma and showed trace levels of MNX and DNX in urine. No metabolites were detected in the liver samples. Thus RDX was metabolized primarily by a method that accomplished both denitration and oxidative cleavage of the ring structure of this compound to form butanal and butanamide metabolites.

Journal Article

Abstract  The gut microflora in some patients with Crohn's disease can be reduced in numbers of butyrate-producing bacteria and this could result in metabolic stress in the colonocytes. Thus, we hypothesized that the short-chain fatty acid, butyrate, is important in the maintenance and regulation of the barrier function of the colonic epithelium.

Confluent monolayers of the human colon-derived T84 or HT-29 epithelial cell lines were exposed to dinitrophenol (DNP (0.1 mM), uncouples oxidative phosphorylation) + Escherichia coli (strain HB101, 10(6) cfu) +/- butyrate (3-50 mM). Transepithelial resistance (TER), and bacterial internalization and translocation were assessed over a 24-hour period. Epithelial ultrastructure was assessed by transmission electron microscopy.

Epithelia under metabolic stress display decreased TER and increased numbers of pseudopodia that is consistent with increased internalization and translocation of the E. coli. Butyrate (but not acetate) significantly reduced the bacterial translocation across DNP-treated epithelia but did not ameliorate the drop in TER in the DNP+E. coli exposed monolayers. Inhibition of bacterial transcytosis across metabolically stressed epithelia was associated with reduced I-kappaB phosphorylation and hence NF-kappaB activation.

Reduced butyrate-producing bacteria could result in increased epithelial permeability particularly in the context of concomitant exposure to another stimulus that reduces mitochondria function. We speculate that prebiotics, the substrate for butyrate synthesis, is a valuable prophylaxis in the regulation of epithelial permeability and could be of benefit in preventing relapses in IBD.

Journal Article

Abstract  This experimental study deals with the colloidal stability of sterically functionalized magnetite nanoparticles in a low dielectric constant organic solvent with different concentrations of technical grade polymers. Those dispersions are the starting point of a solution and spray drying process chain to synthesize highly filled nanocomposite materials with nanoparticle volume concentrations exceeding 10%. We introduce a thermo gravimetric method together with light extinction and dynamic light scattering measurements to gain quantitative information on the concentration of primary particles and the mechanism of destabilization or stabilization by polymer addition. Poly(vinyl butyral) is found to stabilize the dispersion considerably caused by stronger interactions with the fatty acid coated magnetite particles quantified by means of adsorption measurements. Both poly(methyl methacrylate) as well as two grades of poly(bisphenol A carbonate) are found to destabilize the dispersion due to depletion flocculation over the entire concentration range investigated However there is a significant quantity of a stable fraction of primary nanoparticles in the supernatant after depletion flocculation occurred. This fraction of primary particles is increasing with decreasing polymer concentration. We furthermore point out important concerns and limitations for the composition of and concentrations in such complex colloidal systems for use in industrially relevant processes.

Journal Article

Abstract  Titanate sol-gel layers imprinted with carbonic acids were used as sensitive layers on quartz crystal microbalance. These functionalized ceramics enable us detection of volatile organic compounds such as ethanol, n-propanol, n-butanol, n-hexane, n-heptane, n-/iso-octane, and n-decane. Variation of the precursors (i.e., tetrabutoxy titanium, tetrapropoxy titanium, tetraethoxy titanium) allows us to tune the sensitivity of the material by a factor of 7. Sensitivity as a function of precursors leads to selective inclusion of n-butanol vapors down to 1 ppm. The selectivity of materials is optimized to differentiate between isomers, e.g., n- and iso-octane. The results can be rationalized by correlating the sensor effects of hydrocarbons with the Wiener index. A mass-sensitive sensor based on titanate layer was also developed for monitoring emanation of degraded engine oil. Heating the sensor by a meander avoids vapor condensation. Thus, a continuously working oil quality sensor was designed.

Journal Article

Abstract  Tertiary butyl alcohol (TBA) was administered to groups of 15 female B6C3F1 mice in drinking water at concentrations of 0, 2.0 or 20 mg TBA ml(-1), for 14 days, for assessment of gross and histological changes in the liver and thyroid, thyroid hormones (T3, T4, and TSH), total hepatic cytochrome P450 (Cyp) content, specific Cyp activities and quantitative PCR analysis of specific Cyp enzymes (Cyp1a1, Cyp2b9, Cyp2b10, Cyp3a11), sulfuryltransferases (ST1a1, ST2a2, and STn) and glucuronyltransferases (UGT1a1, UGT2b1, and UGT2b5). Phenobarbital (PB) was administered to a positive control group by oral gavage at a daily dose of 80 mg kg(-1). TBA caused, on day 14, a reduction in circulating T3 (12-15% decrease) and a dose-dependent reduction in T4 (13-22% decrease), with no evidence of thyroid pathology. Two of five livers examined in the 20 mg TBA ml(-1) dose group showed mild, diffuse centrilobular hypertrophy. On day 14, Cyp 7-benzoxyresorufin-O-debenzylase activity was significantly induced 12-fold by TBA at 20 mg ml(-1), and 1.8-fold at the 2.0 mg TBA ml(-1) concentration. Cyp 7-pentoxyresorufin-O-dealkylase activity was slightly induced (2.1-fold) by 20 mg TBA ml(-1) on day 14. Quantitative PCR analysis of gene transcripts showed a significant induction of Cyp2b10 and ST1a1 with both TBA concentrations, and a slight induction of Cyp2b9 at 20 mg TBA ml(-1) only. PB induced all phase I and phase II gene transcripts except for Cyp1a1 and Cyp2b9. These findings suggest that TBA, at and below doses used in chronic studies, is an inducer of phase I and phase II liver enzymes, with resulting decreases in circulating thyroid hormones in B6C3F1 mice.

Journal Article

Abstract  For four decades, the Draize test has remained the accepted method for evaluating eye irritation. Criticisms center around the inhumane treatment of animals and the irreproducibility of the subjective scoring procedure. The objective of this study was to determine if changes in corneal thickness obtained using a slit-lamp pachometer could be used to replace the Draize scoring procedure and provide a method for quantifying ocular irritation. Twenty-four chemicals (six surfactants, seven alcohols, four ketones, four acetates, and three aromatics) were instilled in the conjunctival sacs of rabbits and irritation monitored by Draize scoring and changes in corneal thickness. The Draize procedure was more adept at detecting minor conjunctival damage, but corneal thickness exhibited less variation and increased sensitivity for detection of healing reactions. A significant linear correlation (y = l.736x + 92.883) was established between Draize score and corneal thickness changes with a correlation coefficient (r) of 0.86 and an F-value for regression of 261.3. Using these findings, an ocular irritation ranking system is proposed based upon the percentage of corneal swelling. Ocular irritation potential was ranked for the chemical groups tested (surfactants> alcohols> ketones or acetates> aromatics). Quantitation of ocular irritation from changes in corneal thickness provides objective, numerical data applicable to standard parametric statistical procedures. This should eliminate the subjective bias inherent to Draize scoring and decrease intra- and interlaboratory variability. ® 1989 Society orToxicology.

Journal Article

Abstract  This work proposed a gas sensor for the determination of tert-butyl mercaptan, one of the highly toxic volatile sulfur compounds, which was based on cataluminescence emission during its catalytic oxidation on the surface of nanosized V(2)O(5). The cataluminescence characteristics and the optimum conditions, including the morphology of sensing material, the wavelength of cataluminescence emission, the oxygen flow rate and working temperature were investigated in detail. Under the optimized conditions, the calibration curve of the relative cataluminescence intensity versus the concentration of tert-butyl mercaptan vapor was made, with the linear range of 5.6-196 microg mL(-1) and the detection limit of 0.5 microg mL(-1) (S/N=3). The relative standard deviation (R.S.D.) (n=5) of relative cataluminescence intensity for 84 microg mL(-1) tert-butyl mercaptan was 3.6%. There is no or weak response to some common substances, such as formic acid, alcohol (methanol, ethanol, propanol, isopropanol, n-butanol, isoamyl alcohol), o-dichlorobenzene, acetonitrile, ethyl acetate, aldehyde (formaldehyde, acetaldehyde and propanal), 1,2-dichloroethane and ammonia. Furthermore, the proposed sensor was successfully used for determining tert-butyl mercaptan in four artificial samples, with a good recovery. The results demonstrated that the proposed gas sensor had a promising capability for the tert-butyl mercaptan in routine monitoring.

Journal Article

Abstract  Abstract: In this paper, we evaluate the efficiency of UV/H2O2 process to remove methyl tert-butyl ether (MtBE) and tertiary butyl alcohol (tBA) from a drinking water source. Kinetic models were used to evaluate the removal efficiency of the UV/H2O2 technologies with different pretreatment options and light sources. Two commercial UV light sources, i.e. low pressure, high intensity lamps and medium pressure, high intensity lamps, were evaluated. The following pretreatment alternatives were evaluated: (1) ion exchange softening with seawater regeneration (NaIX); (2) Pellet Softening; (3) weak acid ion exchange (WAIX); and (4) high pH lime softening followed by reverse osmosis (RO). The presence or absence of a dealkalization step prior to the UV/H2O2 Advanced Oxidation Process (AOP) was also evaluated for each pretreatment possibility. Pretreatment has a significant impact on the performance of UV/H2O2 process. The NaIX with dealkalization was shown to be the most cost effective. The electrical energy per order (EEO) values for MtBE and tBA using low pressure high output UV lamps (LPUV) and 10mg/LH2O2 are 0.77 and 3.0kWh/kgal-order, or 0.20 and 0.79kWh/m3-order, respectively. For medium pressure UV high output lamps (MPUV), EEO values for MtBE and tBA are 4.6 and 15kWh/kgal-order, or 1.2 and 4.0kWh/m3-order, for the same H2O2 dosage. [Copyright 2008 Elsevier] Copyright of Water Research is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts)

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Journal Article

Abstract  Enantioenriched poly(hydroxy butyrate) (PHB) is a biodegradable polyester of significant commercial interest as an environmentally benign substitute of commodity polyolefines. We report on the design and development of new chiral indole-based ligand families and on their chromium(III) complexes as enantioselective catalysts for the conversion of propylene oxide and carbon monoxide to enantioenriched [beta]-butyrolactone, the key monomer for the production of PHB by ring-opening polymerization. The enantioselective carbonylation catalysts are based on new chiral tri- and tetradentate [N2O] and [N4] chromium(III) complexes containing chiral indolaldimine ligand scaffolds. The conceptual design of these ligands is inspired by Jacobsen's salicylaldimine lead structure; the key difference is an exchange of the salicyl-O-donor against an indole-N-donor, allowing additional structural diversity and stereoelectronic tuning by the indole substitution pattern. Synthetically, chiral indolealdimines are easily accessible from 7-formylindoles by standard Schiff base condensation with chiral amine building blocks; the 7-formylindoles in turn are synthesized from the corresponding 7-bromoindoles by the Rapoport synthesis, and the starting 7-bromoindoles are accessible from 2-bromoaniline by the classical Fischer indole synthesis. Three generations of chiral [N2O] and [N4] chromium(III) catalysts have been developed and evaluated in the enantioselective carbonylation of racemic propylene oxide with carbon monoxide using tetracarbonylcobaltate as the nucleophilic reagent for the insertion of carbon monoxide into the activated propylene oxide/chiral Lewis acid complex. The best catalyst out of 10 candidates showed at a temperature of 80 °C an activity of 37% conversion, 100% chemoselectivity, and 19% stereoselectivity.

Journal Article

Abstract  Ornithine carbamyl transferase (OCT), an enzyme found predominantly in the liver, is released into the bloodstream when liver cells are ruptured. The measurement of serum OCT activity is a convenient, specific, and sensitive assay of liver damage. This test was used to evaluate the effect of several widely used solvents on the livers of guinea pigs. Each solvent was administered intraperitoneally, and 24 hours later serum OCT activity was measured. Many of the solvents tested failed to increase serum OCT activity even at near-lethal doses. Of the thirty-three solvents evaluated, two produced elevations in serum OCT activity at relatively low doses (less than 50 mg/kg), five at moderate doses (50 to 500 mg/kg), and nine at high doses (greater than 500 mg/kg).

Journal Article

Abstract  Monoclinic monazite-type EuPO4 and LaPO4:Eu nanorods were synthesized by a microemulsion-assisted solvothermal method. Their morphologies, structures, and fluorescent properties were characterized by SEM, XRD, and photoluminescence (PL) modern analytic means, respectively. The aspect ratios of EuPO4 and LaPO4:Eu nanorods have a decreasing tendency with increasing carbon chain length of assisted surfactants. When the assisted surfactant was n-butyl alcohol, the EuPO4 exhibited nanorod morphology with diameters from 20 to 30 nm and lengths from 100 to 150 nm. When the assisted surfactant was n-pentanol, the EuPO4 nanorods had lengths between 200 and 300 nm and a diameter range similar to that of the n-butyl alcohol nanorods. When the assisted surfactant was n-hexanol and n-octyl alcohol, only elliptical EuPO4 products were obtained. The LaPO4:Eu nanorods synthesized in the presence of different assisted-surfactants exhibited elliptical morphologies with diameters of 40-60 nm and lengths of 70-110 nm. The LaPO4:Eu and EuPO4 nanorods showed a orange prominent emission peak from magnetic-dipole transition 5D0 --> F1 (593 nm) of Eu3+ ions whose sites in the EuPO4 and LaPO4:Eu nanorods have C1 symmetry. Compared with bulk LaPO4:Eu, the fine structure of the Eu-O charge transfer band has very small red shift resulting from the slight increase of the length of Eu-O bond due to nanoscale size effect.

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Journal Article

Abstract  The methanol and methanol-chloroform (1:1) extracts of the freshly collected Haliclona exigua showed minumim inhibitory concentration (MIC) of 125 mu g/ml and 250 mu g/ml respectively in in vitro studies, but when both of these were tested in vivo in rats, only methanol-chloroform showed 80% inhibition of trophozoites at the dose of 900 mg/kg body weight against Entameba histolytica. Therefore only methanol-chloroform extract was further fractionated into four fractions (n-hexane, chloroform, n-butanol soluble and n-butanol insoluble fractions). Out of these, only n-hexane and n-butanol soluble fractions showed 80% inhibition of trophozoites at 900 mg/kg dose. Further the chromatography of the n-butanol fraction yielded araguspongin-C which showed promising results at different doses.

Journal Article

Abstract  The basic secretagogues, such as compound 48/80 (c48/80) and mastoparans, are widely used histamine-releasing agents and their mechanism of action is commonly attributed to a direct, receptor-bypassing property to activate the G(i/o) class of G proteins. We tested here whether c48/80 could directly stimulate [(35)S]guanosine-5'-[gamma-thio]triphosphate ([(35)S]GTPgammaS) binding to rat brain sections in an attempt to visualize the entire signaling pool of G(i/o) in its native neuroanatomical context. Instead of direct G(i/o) activation, c48/80 (100 microg ml(-1)) from various suppliers stimulated brain phospholipase D (PLD) activity, leading to the generation of endogenous phospholipids capable of activating brain white matter-enriched, G(i/o)-coupled lysophosphatidic acid (LPA) receptors. This response was sensitive to 1-butanol and was potently reversed by the LPA(1)/LPA(3) receptor-selective antagonist Ki16425 (IC(50) 59+/-13 nM, mean+/-s.e.m.), and showed age-dependent decline, closely reflecting known developmental regulation of the PLD-LPA(1) receptor axis in the CNS. In addition, c48/80 was found to modestly activate hippocampal 5-HT(1A) receptors in a pH-dependent and antagonist-sensitive manner. Consistent with the lack of direct G(i/o)-activating properties in brain sections, c48/80 showed no activity in classical membrane [(35)S]GTPgammaS binding assays. Instead, c48/80 from one particular manufacturer elicited non-specific effect in these assays, therefore challenging the previous interpretations regarding the compound's ability to activate G proteins directly. We conclude that c48/80 is not a receptor-bypassing general G protein activator but rather activates PLD, leading to generation of endogenous LPA receptor-activating phospholipids. This property may also contribute to the compound's ability to release histamine from mast cells.

Journal Article

Abstract  Aim: Transcranial Doppler sonography (TCD) is increasingly used in cerebrovascular disease for monitoring brain perfusion. It allows estimation of cerebral blood flow (CBF) by the measurement of cerebral blood flow velocity (CBFV). The CBFV as well as CB F are intimately associated with the intravascular CO2-concentration. Thus, hyper- or hypocapnia can be used to induce a defined range of blood flows. The aim of our study was the comparison of vasomotor reactivity assessed with simultaneous TCD and quantitative regional CBF-measurements (rCBF) by PET (serving as the reference method for in-vivo quantification of rCBF). Patients, methods: Six healthy young volunteers participated in this study. CBF was measured using O-15-butanol PET. A flow and dispersion-model was fitted to the measured time activity curves using arterial input curves. Each subject underwent five scans at five different end-tidal CO2 levels (EtCO2): 25, 32, 40, 48, and 55 mmHg. CBFV was assessed by continuous bilateral TO of the middle cerebral artery (MCA). Volumes of interest for rCBF determination were placed in grey matter of the prefrontal cortex (PFC) as determined from individual MRIs. Comparisons between the rCBF, EtCO2 and CBFV were carried out with regression and correlation analysis and paired t-tests. Results: Strong positive linear correlations of rCBF and CBFV with the CO2-concentration and linear relationships between rCBF and CBFV were found in each individual. Normalised CO2-reactivities measured by TO and PET were closely correlated. Conclusions: TCD-measurements of vascular reactivity in healthy volunteers show a high correlation to those acquired with PET that serves as the reference method of quantitative rCBF-measurement. The results of the MCA insonation are a close approximation of the rCBF changes induced by variations of EtCO2.

Journal Article

Abstract  ETHNOPHARMACOLOGICAL RELEVANCE: Tinospora crispa has been used in folkloric medicine for control of blood pressure, as an antipyretic, for cooling down the body temperature and for maintaining good health.

AIM OF THE STUDY: To investigate the effects and mechanisms of action of an n-butanol extract from the stems of Tinospora crispa (T. crispa extract) on blood pressure and heart rate in anesthetized rats.

MATERIALS AND METHODS: Air-dried stems of T. crispa were extracted with water, followed by partitioned extract with chloroform, ethyl acetate, and finally by n-butanol. The n-butanol soluble part was evaporated under reduced pressure and lyophilization to obtain a crude dried powder (T. crispa extract). The effects and mechanisms of the T. crispa extract on blood pressure and heart rate were studied in anesthetized normal and reserpinized rats in vivo in the presence of different antagonists.

RESULTS: T. crispa extract (1-100 mg/kg, i.v.) caused a decrease in mean arterial blood pressure (MAP) and this effect was inhibited by propranolol, phentolamine, atenolol and/or the β(2)-antagonist ICI-118,551, but not by atropine or hexamethonium. In reserpinized rats, the T. crispa extract had a dual effect: reduction in hypotensive activity, followed by a small increase in blood pressure. The decrease in MAP in reserpinized rat was slightly potentiated by phentolamine, but inhibited by propranolol or ICI-118,551 only if atenolol and phentolamine were also present. The increase in MAP was potentiated by propranolol and ICI-118,551, but was inhibited by phentolamine. The T. crispa extract had a dual effect on heart rate in the normal rat: a small transient decrease, followed by an increase in heart rate. The positive chronotropic effect of T. crispa extract was inhibited by propranolol, phentolamine and atenolol, but not by ICI-118,551, atropine or hexamethonium. Reserpine potentiated the positive chronotropic effect of the T. crispa extract and this effect was inhibited by propranolol, atenolol and ICI-118,551, but not by phentolamine.

CONCLUSIONS: From these results we suggest that T. crispa extract possesses at least three different cardiovascular-active components that act directly via (1) β(2)-adrenergic receptors to cause a decrease in blood pressure, and β(1)- and β(2)-adrenergic receptors to cause an increase in heart rate, (2) α-adrenergic receptors to cause an increase in blood pressure and heart rate, and (3) a non-adrenergic and non-cholinergic pathway to cause a decrease in MAP and heart rate. These findings provide scientific support for the tradition of using this plant to modify the actions of the human cardiovascular system.

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Journal Article

Abstract  This study was planned to investigate whether Lactuca sativa is capable of protecting neurons against glucose/serum deprivation (GSD)-induced cell injury, an in vitro model of brain ischemia. Two neuronlike cells, rat pheochromocytoma-derived cell line (PC12) and mouse neuroblastoma-like cell line (N2a), were cultivated for 24 h in standard media or for 6 and 12 h in GSD condition in the absence or presence of hydro-alcoholic extract (HAE), water fraction (WF), ethyl acetate fraction (EAF) or N-butanol fraction (NBF) of L. sativa. At the end of the experiments, the cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl tetrazolium (MTT) assay. The L. sativa exhibited no cytotoxicity under standard condition unless at very high concentrations. Exposure of PC12 cells to GSD condition for 6 and 12 h led to 44 and 90% decrease in cell viability, respectively. The NBF and especially EAF significantly attenuated GSD-induced cell death. Also, GSD caused a significant reduction in N2a cell viability after 6 h (28%) and 12 h (84%). On the other hand, treatment of N2a cells with EAF blocked the cytotoxic effects of GSD condition. The present study revealed that intermediate polarity fraction of L. sativa (EAF) exerts neuroprotection and has the potential to be used as a new therapeutic strategy for common neurodegenerative disorders such as stroke.

WoS
Journal Article

Abstract  Hopbush (Dodoneae viscosa L.) is an evergreen bush type tree; that is used for hedges and green walls in parks, gardens and houses, in South East of Iran. Propagation by stem cuttings is quicker and cheaper than seed, if the cuttings set in convenient media and rooting hormone. In order to investigate the effects of different media and different concentrations of indole 3-butyric acid (IBA) on rooting of hopbush (Dodonea viscosa L.) cuttings, an experiment was conducted using mist system in greenhouse in spring 2010. The treatments were 3 different media: sand, perlite, and sand + perlite, (1+1 by volume), with 4 levels of IBA concentrations (0 m, 2000 ppm, 4000 ppm, and 6000 ppm). A randomized complete block with factorial design was used with 5 replications. The average and the means were compared by Duncun's multiple range test (1% and 5%); M STAT-C was used for comparing the interaction effects. The effect of medium on number of roots, percentage survival of stem cutting, root fresh weight and dry weight was significant, but on root length was not significantly affected. The effects of different concentrations of hormone on number of roots, percentage survival of stem cutting, root fresh weight and dry weight was significant. The interaction effect of media and hormone on root length was significant, too. The best result was obtained in perlite, with 4000 ppm IBA. The results showed that perlite medium and 4000 ppm IBA concentration can be suggested for soft wood cutting of hopbush.

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