Home About us Contact
|
Home About us Contact | ||
|
|
||
Citrate
Kinds of Citrate Terms modified by Citrate Selected AbstractsPREVENTION OF TUNNELED HAEMODIALYSIS CATHETER (TC) RELATED INFECTIONS USING CATHETER RESTRICTED FILLING WITH GENTAMICIN AND CITRATENEPHROLOGY, Issue 1 2002G Dogra [source] Characterization of chitosan/citrate and chitosan/acetate films and applications for wound healingJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Junichi Tanigawa Abstract In this work, we aimed to develop a scaffold of chitosan (CS) with a porous sponge structure for an artificial skin. The scaffolds were prepared from both CS/citric and CS/acetic solutions. In addition, the cast films were also prepared from the same solutions to compare some of their properties. They were characterized using WAXD, FTIR, DSC, tensile measurements, and SEM observation. It was found that CS/acetate had low crystallinity but CS/citrate was in an amorphous state, resulting in a large ductility with rubbery softness. Despite the different morphologies of CS/citrate and CS/acetate scaffolds, both scaffolds exhibited the wound healing effect available for tissue engineering. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] A study of primary nucleation of calcium oxalate monohydrate: II.CRYSTAL RESEARCH AND TECHNOLOGY, Issue 7 2004Effect of urinary species Abstract Kidney stones consist of various organic and inorganic compounds. Calcium oxalate monohydrate (COM) is the main inorganic constituent of kidney stones. However, the mechanisms for the formation of calcium oxalate kidney stones are not well understood. In this regard, there are several hypotheses including nucleation, crystal growth and/or aggregation of formed COM crystals. The effect of some urinary species such as oxalate, calcium, citrate, and protein on nucleation and crystallization characteristics of COM is determined by measuring the weight of formed crystals and their size distributions under different chemical conditions, which simulate the urinary environment. Statistical experimental designs are used to determine the interaction effects among various factors. The data clearly show that oxalate and calcium promote nucleation and crystallization of COM. This is attributed to formation of a thermodynamically stable calcium oxalate monohydrate resulting from supersaturation. Citrate, however, inhibits nucleation and further crystal growth. These results are explained on the basis of the high affinity of citrate to combine with calcium to form soluble calcium citrate complexes. Thus, citrate competes with oxalate ion for binding to calcium cations. These conditions decrease the amount of free calcium ions available to form calcium oxalate crystals. In case of protein (mucin), however, the results suggest that no significant effect could be measured of mucin on nucleation and crystal growth. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Effect of Sildenafil Citrate (Viagra) on Coronary Flow in Normal SubjectsECHOCARDIOGRAPHY, Issue 1 2008Fuminobu Ishikura M.D. Background: The purpose of this study was to evaluate the effect of sildenafil citrate (Viagra) on coronary function in normal subjects. Methods: The study assessed mean blood pressure, left anterior descending coronary artery (LAD) flow, and echocardiographic variables before and 30 and 60 minutes after taking 50 mg of sildenafil citrate. The mean velocity of LAD flow was assessed with Doppler flow imaging. The study subjects were 6 healthy male volunteers (mean age 37 years). Results: The mean velocity of LAD flow increased 60 minutes after taking sildenafil citrate, but there were no other changes. Two volunteers felt mild flashing and one had mild headache during the study. Conclusion: Sildenafil citrate caused vasodilatation in a normal coronary artery without systemic pressure drops. These results suggest that the agent itself did not have negative effects on the heart in normal subjects. [source] Citrate-mediated increase in the uptake of weathered 2,2-bis(p -chlorophenyl)1,1-dichloroethylene residues by plantsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2002Jason C. White Abstract Experiments were conducted to determine the ability of citrate to enhance the plant uptake of weathered 2,2-bis(p -chlorophenyl) 1,1-dichloroethylene (p,p,-DDE) from soil. Plots containing three rows of clover, mustard, hairy vetch, or rye grass were constructed in soils containing p,p,-DDE. On 11 occasions, the rows of each crop received water or sodium citrate (0.005 or 0.05 M). For each crop, there were significant reductions in p,p,-DDE concentration in the soil fractions (near root and rhizosphere) closely associated with the plant versus bulk soil. The roots of each crop accumulated 2 to 5 times more of the weathered contaminant (dry wt) than present in the bulk soil. Citrate (0.05 M) increased the concentration of p,p,-DDE in the roots of clover, mustard, and hairy vetch by 39% compared with vegetation that received water. In batch desorption studies, the release of weathered p,p,-DDE was significantly greater in the presence of 0.05 M citrate than in water. Citrate increased the extracted aqueous concentrations of five metal ions (Al, Fe, Ca, K, Mn) from soil by five- to 23-fold over distilled water. We hypothesize that citrate physically disrupts the soil through chelation of structural metal ions and release of bound humic material, facilitating p,p,-DDE availability and uptake by plants. [source] Peroxotungstates and Their Citrate and Tartrate DerivativesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 8 2006Shu-Ya Hou Abstract The reaction of potassium tungstate with the biologically relevant ligands citric and tartaric acid, in the presence of hydrogen peroxide, was investigated to discover the effect of pH variation on the product pattern. The reaction with citric acid led to the formation of the dimer K5[WO(O2)2(Hcit)H(Hcit)(O2)2OW]·6H2O (1; H4cit = citric acid) due to carboxyl-carboxylic acid hydrogen bonding in the pH range 2,5; this complex can also be obtained by an exchange reaction between the oxo ligands of the dimeric hydrogencitrate tungstate K4[W2O5(Hcit)2]·4H2O (6) and H2O2. Interestingly, a novel dimeric peroxotungstate K3[W2O3(O2)4(OH)]·H2O (2), without the coordination of citrate ligands, was isolated in the pH range 7,9, as confirmed by 17O NMR solution studies. The reaction of potassium tungstate with (R,R)-tartaric acid afforded the tartratoperoxotungstate K4[W2O2(O2)4{(R,R)-tart}]·3H2O [3; H4tart = (R,R)-tartaric acid] in the pH range 1,3. The dimeric peroxotungstate K2[W2O3(O2)4(H2O)2]·2H2O (4) was found to react with citric or tartaric acid at pH 2,5 or 2,3, respectively, to give species 1 and 3. Evidence that 1 exists as a dimer in solution is presented. The three complexes were characterized by elemental analysis, IR and NMR spectroscopy, and X-ray structural analyses. The formation of these complexes is dictated by pH, and the thermal stabilities of 1 and 3 vary with the coordinated ligands. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] An Energy Dispersive X-ray Diffraction Study of Dioxouranium(VI) in 1 M Lithium CitrateEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 13 2004Ermanno Vasca Abstract An Energy Dispersive X-ray Diffraction (EDXD) study of 0.3 M dioxouranium(VI) in 1 M lithium citrate at pH = 5 is reported. The data are in accordance with the existence of a predominately polynuclear complex containing four U atoms, concluded from potentiometric measurements. The uranium atoms lie at the corners of two triangles sharing one edge. Five O atoms surround each uranyl group, the uranium coordination polyhedron being a pentagonal bipyramid; four U atoms are linked through double or single O bridges. The U,U distances are 3.95 Ĺ and 4.65 Ĺ. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Clomiphene Citrate for Treatment Refractory Chronic Cluster HeadacheHEADACHE, Issue 2 2008Todd Rozen MD A treatment refractory chronic cluster headache patient is presented who became cluster-free on clomiphene citrate. The author has previously reported a SUNCT patient responding to clomiphene citrate. Hypothalamic hormonal modulation therapy with clomiphene citrate may become a new preventive choice for trigeminal autonomic cephalalgias. The possible mechanism of action of clomiphene citrate for cluster headache prevention will be discussed. [source] High Efficacy of Ranitidine Bismuth Citrate, Amoxicillin, Clarithromycin and Metronidazole Twice Daily for Only Five Days in Helicobacter pylori EradicationHELICOBACTER, Issue 2 2001Javier P. Gisbert ABSTRACT Aim. The combination of a proton pump inhibitor (PPI) or ranitidine-bismuth-citrate (Rbc) and two antibiotics for 7,10 days are, at present, the preferred treatments in Helicobacter pylori eradication. However, therapies for fewer than 7 days have been scarcely evaluated and it is unknown whether the length of treatment can be shortened, without a lost of efficacy, if three instead of two antibiotics are used. The aim of our study was to evaluate the efficacy of Rbc plus three antibiotics for only 5 days in H. pylori eradication. Methods. We prospectively studied 80 patients (34% duodenal ulcer, 66% functional dyspepsia) infected by H. pylori. At endoscopy, biopsies were obtained for histological study and rapid urease test, and a 13C-urea breath test was carried out. Urea breath test was repeated 4 weeks after completing eradication treatment with Rbc [400 mg twice a day (bid)], amoxicillin (1 g bid), clarithromycin (500 mg bid) and metronidazole (500 mg bid). All drugs were administered together after breakfast and dinner for 5 days only, and no treatment was administered thereafter. Compliance with therapy was determined from the interrogatory and the recovery of empty envelopes of medications. Results. In 79 out of the 80 patients, H. pylori eradication success or failure was assessed after therapy (one patient was lost from follow-up). All but one of these 79 patients took all the medications (one patient stopped treatment on the day 3 due to nausea/vomiting). Per protocol eradication was achieved in 72/78 (92%; 95% CI, 84,96%) and in 72/80 (90%; 81,95%) by intention-to-treat. Therapy was more effective in patients with duodenal ulcer than in those with functional dyspepsia [100% (87,100%) vs. 85% (73,92%) by intention-to-treat; p < .05]. Adverse effects were described in ten patients (12%), and included the perception of a metallic taste (eight patients), nausea/vomiting (two patients, one of them abandoned the treatment due to this), and diarrhea (two patients). Conclusion. The combination of Rbc, amoxicillin, clarithromycin and metronidazole for only 5 days represents a promising therapy for H. pylori infection, due to its high efficacy, simple posology, low cost and excellent tolerance. [source] Effects of Sildenafil Citrate on Defibrillation EfficacyJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2006KREKWIT SHINLAPAWITTAYATORN M.D. Introduction: Although fatal arrhythmia and sudden death have been reported in patients taking sildenafil citrate, its effect on defibrillation efficacy has not been investigated. The aim of this study was to test the hypothesis that sildenafil citrate increases the shock strength required to successfully defibrillate during ventricular fibrillation (VF). Methods and Results: A total of 26 pigs (20,25 kg) were randomly assigned into three groups. In each group, the defibrillation threshold (DFT) was determined at the beginning of the study using a three-reversal up/down protocol. Each shock (RV-SVC, biphasic) was delivered after 10 seconds of VF. Group 1 (n = 10) received 50 mg and group 2 (n = 10) received 100 mg of sildenafil citrate intravenously at a rate of 2 mL/minute for 50 minutes. Group 3 (n = 6) received 100 mL of saline intravenously at the same rate as in group 1. The DFT was determined again after the drug (drug-DFT) and saline (saline-DFT) administration. For 100-mg sildenafil citrate infusion, the DFT (483 ± 39 V, 18 ± 3 J) was significantly (P < 0.003 and P < 0.01, respectively) higher than the control-DFT (407 ± 123 V, 13 ± 7 J). This sildenafil citrate infusion increased the DFT ,19% by voltage, and ,38% by total energy. After 50-mg sildenafil citrate infusion, the DFT (454 ± 28 V, 15 ± 2 J) was not different than the control DFT (449 ± 28 V, 15 ± 2 J). Saline infusion (391 ± 18 V, 12 ± 1 J) did not alter the control DFT (399 ± 22 V, 12 ± 1 J). Conclusion: The 100-mg sildenafil citrate infusion, representing a supra-therapeutic plasma level, significantly increased the DFT. This finding indicates that VF occurring during supra-therapeutic sildenafil citrate treatment would require a stronger shock to successfully defibrillate. [source] Retrospective Evaluation of Sildenafil Citrate as a Therapy for Pulmonary Hypertension in DogsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2006Jonathan F. Bach DACVIM (SA-IM) Pulmonary arterial hypertension (PH) is a pathologic condition in dogs characterized by abnormally high pressures in the pulmonary circulation and has been associated with a poor outcome. Sildenafil is a type V phosphodiesterase inhibitor that produces nitric oxide-mediated vasodilatation. Sildenafil treatment decreases pulmonary arterial pressure and pulmonary vascular resistance in people with PH. The purpose of this study was to describe the clinical characteristics and outcome of dogs with PH treated with sildenafil. The cardiology database was searched for dogs with PH treated with sildenafil. PH was defined as systolic pulmonary arterial pressure (PAPS) 25 mmHg at rest. Medical records were reviewed for the following information: signalment, duration and type of clinical signs before treatment, underlying disease, estimated or measured PAPS, dosage and dosing interval of sildenafil, and the effect of treatment on clinical signs and pulmonary arterial pressure and survival time. Thirteen affected dogs were identified. Clinical signs included collapse, syncope, respiratory distress, and cough. Duration of clinical signs before presentation ranged from 3 days to 5 months. An underlying cause was identified in 8 dogs. The median sildenafil dosage was 1.9 mg/kg. Ten dogs received concurrent medications. Median PAPS was 90 mmHg; 8 dogs were reevaluated after therapy, and the median decrease in PAPS was 16.5 mmHg. The median survival time of all dogs was 91 days. Sildenafil appeared to be well tolerated in dogs with PH and was associated with decreased PAPS and amelioration of clinical signs in most. Sildenafil represents a reasonable treatment option for dogs with pulmonary hypertension. [source] Comparison of the Effect of the Aromatase Inhibitor, Anastrazole, to the Antioestrogen, Tamoxifen Citrate, on Canine Prostate and SemenREPRODUCTION IN DOMESTIC ANIMALS, Issue 2009G Gonzalez Contents This study compared the efficiency of the aromatase inhibitor, anastrazole, with the antioestrogenic receptor blocker, tamoxifen, on normal (NRL) and hyperplastic prostate glands. Forty healthy dogs were classified as NRL (n = 18) or abnormal (ABN) with benign prostate hyperplasia (n = 22). The dogs were randomly assigned to one of the following six groups, treated for 60 days; oral placebo for normal (NRL-PLC; n = 6) and abnormal (ABN-PLC; n = 6), oral anastrazole 0.25,1 mg/day, for normal (NRL-ANZ, n = 6) and abnormal (ABN-ANZ, n = 8) and oral tamoxifen citrate 2.5,10 mg/day for normal (NRL-TMX; n = 6) and abnormal (ABN-TMX; n = 8) dogs. The dogs were evaluated before treatment and then monthly for 4 months. At the end of the treatment, the prostatic volume decreased by 28.5 ± 4.3%, 21.6 ± 6.3% and 0.7 ± 1.0% in the ABN-TMX, ABN-ANZ and ABN-PLC (p < 0.01), respectively. From then on, prostatic volume began to increase without reaching pre-treatment values at the end of the study. In the ABN animals, there were no differences for this parameter between ANZ and TMX treatment (p > 0.1), whereas in the NRL animals ANZ produced a less pronounced decrease (p < 0.05), libido, testicular consistency and scrotal diameter decreased during treatment in the TMX group (p > 0.05). These parameters and sperm volume, count, motility and morphological abnormalities remained unaltered throughout the study in the ANZ and PLC groups (p > 0.05). There were no haematological nor biochemical side effects. Anastrazole might offer a safe and effective alternative for the medical management of dogs with benign prostatic hyperplasia. [source] Effects of Acetoacetate on in vitro Development of Bovine Embryos in Medium Containing Citrate and Myo-inositolREPRODUCTION IN DOMESTIC ANIMALS, Issue 3-4 2001E Gómez This study investigated bovine embryo development in vitro in the presence of acetoacetate in serum-free medium. In vitro -matured and fertilized oocytes from ovaries of slaughtered cows were cultured in synthetic oviduct fluid (SOF) containing citrate, myo-inositol, lactate and pyruvate. In the medium with acetoacetate this compound replaced both lactate and pyruvate as energy sources. Three experiments were carried out: (1) to test development in medium with acetoacetate and bovine serum albumin; (2) to analyse the effects of acetoacetate that were dependent upon citrate and myo-inositol; and (3) to determine the effects of acetoacetate in the presence of serum. Blastocyst development was recorded at day 8 and the number of cells of expanded blastocysts obtained were counted. Blastocysts development was reduced in medium with 1.8, 3.6 or 7.2 mM acetoacetate in comparison with the control with or without lactate and pyruvate. The detrimental effect of acetoacetate was independent of the presence of citrate and myo-inositol, but serum added to culture medium protected against this effect. Citrate and myo-inositol did not improve blastocyst formation. Morphological quality and cell number of blastocysts were similar between groups. [source] Clomiphene Citrate and Testosterone Gel Replacement Therapy for Male Hypogonadism: Efficacy and Treatment CostTHE JOURNAL OF SEXUAL MEDICINE, Issue 1pt1 2010Frederick Taylor MD ABSTRACT Introduction., The efficacy of oral clomiphene citrate (CC) in the treatment of male hypogonadism and male infertility (MI) with low serum testosterone and normal gonadotropin levels has been reported. Aim., The aim of this article is to evaluate CC and testosterone gel replacement therapy (TGRT) with regard to biochemical and clinical efficacy and cost. Main Outcome Measures., The main outcome measures were change in serum testosterone with CC and TGRT therapy, and change in the androgen deficiency in aging male (ADAM) questionnaire scores with CC therapy. Methods., Men receiving CC or TGRT with either Androgel® 1% or Testim® 1% for hypogonadism (defined as testosterone < 300 ng/mL) or MI were included. Serum values were collected 1,2 months after treatment initiation and semi-annually thereafter. Retrospective data collection was performed via chart review. Subjective follow up of patients receiving CC was performed via telephone interview using the ADAM questionnaire. Results., A hundred and four men (65 CC and 39 TGRT) were identified who began CC (50 mg every other day) or TGRT (5 g). Average age (years) was 42(CC) vs. 57 (TGRT). Average follow up was 23 months (CC, range 8,40 months) vs. 46 months (TGRT, range 6,149 months). Average posttreatment testosterone was 573 ng/dL in the CC group and 553 ng/dL in the TGRT group (P value < 0.001). The monthly cost of Testim® 1% (5 gm daily) is $270, Androgel® 1% (5 gm daily) is $265, and CC (50 mg every other day) is $83. Among CC patients, the average pretreatment ADAM score was 4.9 vs. 2.1 at follow up (P < 0.05). Average pretreatment ADAM sexual function domain score was 0.76 vs. 0.23 at follow up (P < 0.05). There were no adverse events reported. Conclusion., CC represents a treatment option for men with hypogonadism, demonstrating biochemical and clinical efficacy with few side effects and lower cost as compared with TGRT. Taylor F, and Levine L. Clomiphene citrate and testosterone gel replacement therapy for male hypogonadism: Efficacy and treatment cost. J Sex Med 2010;7:269,276. [source] ORIGINAL RESEARCH,ED PHARMACOTHERAPY: Sildenafil Citrate 100 mg Starting Dose in Men with Erectile Dysfunction in an International, Double-Blind, Placebo-Controlled Study: Effect on the Sexual Experience and Reducing Feelings of Anxiety About the Next Intercourse AttemptTHE JOURNAL OF SEXUAL MEDICINE, Issue 10 2009Oleg B. Loran MD ABSTRACT Introduction., Sildenafil citrate 50 mg is the recommended starting dose for men with erectile dysfunction (ED); however, most men are later titrated to sildenafil 100 mg for improved efficacy. Aim., Assess the tolerability and efficacy of sildenafil initiated at the 100-mg dose in men with ED. Methods., Men with ED (score ,25 on the Erectile Function domain of the International Index of Erectile Function) who had received ,6 total doses of a phosphodiesterase type 5 inhibitor and none within 4 weeks were randomized to 8 weeks of double-blind, placebo-controlled (DBPC), fixed-dose treatment (50 or 100 mg sildenafil or placebo) followed by 4 weeks of open-label flexible-dose sildenafil (50 or 100 mg). Main Outcome Measures., Efficacy, tolerability, treatment satisfaction, and other end points were measured at baseline and/or the end of the double-blind and open-label phases and compared between placebo and sildenafil initiated at doses of 50 and 100 mg. Results., Improvements in DBPC patient-reported outcomes from baseline were statistically significant for both sildenafil 50 and 100 mg compared with placebo. At the end of DBPC treatment, 56% of men on the 100-mg dose felt no anxiety about the next intercourse attempt compared with 39% in the 50-mg group (odds ratio 2.03; P = 0.0197). Changes in functional scores from baseline were not statistically significant with the 100-mg dose compared with the 50-mg dose in the DBPC. Measures of treatment satisfaction and sexual experience significantly favored the 100-mg dose compared with the 50-mg dose in the DBPC. There was no increase in adverse events with the higher dose. Conclusions., Sildenafil at 50 mg or 100 mg significantly improved erection quality, treatment satisfaction, anxiety levels, and the sexual experience compared with placebo during DBPC. Sildenafil 100 mg improved the sexual experience and treatment satisfaction, and reduced feelings of anxiety compared with the 50-mg dose. Loran OB, Ströberg P, Lee SW, Park NC, Kim SW, Tseng LJ, Collins S, and Stecher VJ. Sildenafil citrate 100 mg starting dose in men with erectile dysfunction in an international, double-blind, placebo-controlled study: Effect on the sexual experience and reducing feelings of anxiety about the next intercourse attempt. J Sex Med 2009;6:2826,2835. [source] An Open-Label, Multicenter, Flexible Dose Study to Evaluate the Efficacy and Safety of Viagra® (Sildenafil Citrate) in Korean Men with Erectile Dysfunction and Arterial Hypertension who are Taking Antihypertensive AgentsTHE JOURNAL OF SEXUAL MEDICINE, Issue 10 2008Hyun Jun Park MD ABSTRACT Introduction., Erectile dysfunction (ED) is common among men taking antihypertensive agents to control blood pressure. Aim., We evaluated the efficacy and safety of sildenafil citrate in men with ED taking antihypertensive agents. Methods., A total of 198 male subjects, aged 20 years and older were enrolled. This study was conducted for 10 weeks as an open-label, multicenter and flexible dose trial with a 2-week screening period and an 8-week treatment phase. Main Outcome Measures., Subjects were asked to complete Event Log Worksheets, as well as the International Index of Erectile Function (IIEF) and the Global Efficacy Assessment Questions (GEAQ) questionnaires during the study period. Results., The average age among the 167 subjects who completed the study was 55.8 (31.7 to 77.1). The scores for questions 3 and 4 of IIEF improved from 2.3 and 1.8 at baseline to 3.7 and 3.4 at week 4 and 3.8 and 3.4 at week 8, respectively. There were 86.3% of the patients reported improved erectile function at week 8; 88.3% of the patients reported improved ability to achieve sexual intercourse at week 8. There were no significant differences observed in the responses to questions 3 and 4 of IIEF and GEAQ by the number of antihypertensive agents taken. The adverse events were facial flushing (20.1%), headache (11.7%), palpitation (5.0%), rhinitis (2.8%), URI (2.8%), dizziness (2.2%), dyspnea (2.2%), and nausea (1.7%). Conclusions., Sildenafil citrate is an effective treatment for ED; it is safe and well tolerated by patients with ED taking multiple antihypertensive agents for arterial hypertension. Park HJ, Park NC, Shim HB, Park JK, Lee SW, Park K, Kim SW, Moon KH, Lee DH, and Yoon SJ. An open-label, multicenter, flexible dose study to evaluate the efficacy and safety of Viagra® (sildenafil citrate) in Korean men with erectile dysfunction and arterial hypertension who are taking antihypertensive agents. J Sex Med 2008;5:2405,2413. [source] ORIGINAL RESEARCH,ED PHARMACOTHERAPY: Psychosocial Outcomes and Drug Attributes Affecting Treatment Choice in Men Receiving Sildenafil Citrate and Tadalafil for the Treatment of Erectile Dysfunction: Results of a Multicenter, Randomized, Open-Label, Crossover StudyTHE JOURNAL OF SEXUAL MEDICINE, Issue 4 2006FRCGP, John Dean MBBS ABSTRACT Introduction., Although sildenafil citrate (sildenafil) and tadalafil are efficacious and well-tolerated treatments for erectile dysfunction (ED), preference studies have shown that patients may favor one medication over the other. Aim., To determine whether psychosocial outcomes differed when men with ED received tadalafil compared with sildenafil. Main Outcome Measures., Measures included a treatment preference question, Psychological and Interpersonal Relationship Scales (PAIRS), and Drug Attribute Questionnaire. Methods., Randomized, open-label, crossover study. After a 4-week baseline, men with ED (N = 367; mean age = 54 years; naďve to type 5 phosphodiesterase inhibitor therapy) were randomized: tadalafil for 12 weeks then sildenafil for 12 weeks or vice versa (8-week dose optimization/4-week assessment phases). During dose optimization, patients started with 10 mg tadalafil, or 25 or 50 mg sildenafil and could titrate to their optimal dose (10 or 20 mg tadalafil; 25, 50, or 100 mg sildenafil). Medications were taken as needed. Patients completing both 12-week periods chose which medication to continue during an 8-week extension. Results., Of 291 men completing both treatment periods, 71% (N = 206) chose tadalafil and 29% (N = 85) chose sildenafil (P < 0.001) for the 8-week extension. When taking tadalafil compared with sildenafil men had higher mean endpoint scores on PAIRS Sexual Self-Confidence (tadalafil = 2.91 vs. sildenafil = 2.75; P < 0.001) and Spontaneity (tadalafil = 3.32 vs. sildenafil = 3.17; P < 0.001) Domains and a lower mean endpoint score on Time Concerns Domain (tadalafil = 2.2 vs. sildenafil = 2.59; P < 0.001). The two most frequently chosen drug attributes to explain treatment preference were ability to get an erection long after taking the medication and firmness of erections. Tadalafil and sildenafil were well tolerated with 12 (3.3%) patients discontinuing for an adverse event. Conclusions., As measured with PAIRS, men with ED had higher sexual self-confidence and spontaneity and less time concerns related to sexual encounters when treated with tadalafil compared with sildenafil. These psychosocial outcomes may help explain why more men (71%) preferred tadalafil for the treatment of ED in this clinical trial. Dean J, Hackett GI, Gentile V, Pirozzi-Farina F, Rosen RC, Zhao Y, Warner MR, and Beardsworth A. Psychosocial outcomes and drug attributes affecting treatment choice in men receiving sildenafil citrate and tadalafil for the treatment of erectile dysfunction: Results of a multicenter, randomized, open-label, crossover study. J Sex Med 2006;3:650,661. [source] ORIGINAL RESEARCH,PHARMACOTHERAPY: Hemodynamic Effects of Sildenafil Citrate and Isosorbide Mononitrate in Men with Coronary Artery Disease and Erectile DysfunctionTHE JOURNAL OF SEXUAL MEDICINE, Issue 3 2005Graham Jackson ABSTRACT Introduction., Mild hemodynamic effects have been reported with sildenafil citrate therapy. Aim., To compare the hemodynamic effects of sildenafil and isosorbide mononitrate (ISMN) in men with coronary artery disease and erectile dysfunction. Methods., A total of 31 men aged 35 years or older with coronary artery disease (at least 50% narrowing of the left main stem or at least 70% narrowing of any other coronary artery) and erectile dysfunction (receiving medication for erectile dysfunction or scoring less than 26 out of a maximum score of 30 on the erectile function domain questions of International Index of Erectile Function) were randomized to sildenafil 100 mg (n = 10), ISMN 40 mg (n = 11), or placebo (n = 10) in this single-dose multicenter study. Main Outcome Measures., Hemodynamic parameters were measured at baseline, 1, 2, 4, and 6 hours post dose. Results., Compared with baseline, cardiac index increased slightly with sildenafil (0.29 L/min/m2 at 1 hour) and decreased slightly with placebo (,0.12 L/min/m2 at 4 hours) and ISMN (,0.14 L/min/m2 at 1 hour). The stroke volume index increased from baseline at each time point post dose with sildenafil (4.4 mL/m2 at 2 hours), but decreased with ISMN (,5.8 mL/m2 at 1 hour) and placebo (,2.8 mL/m2 at 4 hours). ISMN reduced mean arterial pressure more than sildenafil did (,22 vs. ,10 mm Hg at 2 hours, respectively). Both sildenafil and ISMN increased heart rate (4 vs. 7 beats/minute at 1 hour, respectively) and decreased systemic vascular resistance, but sildenafil produced greater reductions in pulmonary vascular resistance. There were no serious adverse events in the sildenafil group. Conclusions., Sildenafil 100 mg was well tolerated and induced smaller changes in central and peripheral hemodynamic pressures compared with ISMN 40 mg. Moreover, sildenafil selectively reduced pulmonary resistance, which may have clinical importance in pulmonary hypertension. [source] Profound hypocalcaemia in a patient being anticoagulated with citrate for continuous renal replacement therapyANAESTHESIA, Issue 12 2009D. J. R. Morgan Summary Citrate, as an anticoagulant for continuous renal replacement therapy in critically ill patients, has some potential advantages over heparin, including a prolonged dialysis filter life and reduced risk of bleeding. The key parameter involved in monitoring the adequacy and safety of citrate anticoagulation during continuous renal replacement therapy pertains to the ionised and total plasma calcium levels. We report a case of severe systemic hypocalcaemia during continuous renal replacement therapy with citrate anticoagulation resulting from relentless sequestration of calcium due to undiagnosed evolving rhabdomyolysis. Although excessive systemic citrate accumulation can also cause hypocalcaemia, this complication was not observed in our patient. While an acceptable lower limit of ionised calcium remains unknown, severe rhabdomyolysis needs to be considered when a patient's ionised calcium levels are not responsive to standard calcium replacement therapy during continuous renal replacement therapy using citrate anticoagulation in critically ill patients. [source] Characterization of chitosan/citrate and chitosan/acetate films and applications for wound healingJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Junichi Tanigawa Abstract In this work, we aimed to develop a scaffold of chitosan (CS) with a porous sponge structure for an artificial skin. The scaffolds were prepared from both CS/citric and CS/acetic solutions. In addition, the cast films were also prepared from the same solutions to compare some of their properties. They were characterized using WAXD, FTIR, DSC, tensile measurements, and SEM observation. It was found that CS/acetate had low crystallinity but CS/citrate was in an amorphous state, resulting in a large ductility with rubbery softness. Despite the different morphologies of CS/citrate and CS/acetate scaffolds, both scaffolds exhibited the wound healing effect available for tissue engineering. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] B2 kinin receptors mediate the Indian red scorpion venom-induced augmentation of visceral reflexes via the nitric oxide cyclic guanosine monophosphate pathwayACTA PHYSIOLOGICA, Issue 4 2009S. Kanoo Abstract Aim:, This study was performed to delineate the kinin (receptor)-dependent pathways in the Indian red scorpion (Mesobuthus tamulus; MBT) venom-induced pulmonary oedema as well as the augmentation of cardio-pulmonary reflexes evoked by phenyldiguanide (PDG). Methods:, In urethane-anaesthetized adult rats, the effect of venom on the PDG reflex responses (blood pressure, heart rate and respiration rate) and the pulmonary water content was ascertained using various antagonists(des- Arg, B1 receptor antagonist; Hoe 140, B2 receptor antagonist; N, -nitro- l -arginine methyl ester (l -NAME), nitric oxide (NO) synthase inhibitor; methylene blue, soluble guanylate cyclase inhibitor; and glibenclamide, K+ATP channel blocker). The effect of phosphodiesterase V inhibitor (sildenafil citrate) on the reflex response and the pulmonary water content was also examined and compared with venom-induced responses. Results:, Intravenous injection of PDG (10 ,g kg,1) evoked apnoea, bradycardia and hypotension lasting >60 s. Exposure to MBT venom (100 ,g kg,1) for 30 min augmented the PDG reflex responses by two times and increased the pulmonary water content, significantly. Hoe 140 blocked the venom-induced responses (augmentation of PDG reflex and increased pulmonary water content) whereas des-Arg did not. l -NAME, methylene blue or glibenclamide also blocked the venom-induced responses. Furthermore, sildenafil citrate (that increases cGMP levels) produced augmentation of PDG reflex response and increased the pulmonary water content as seen with venom. Conclusion:, The results indicate that venom-induced responses involve B2 kinin receptors via the NO-dependent guanylate cyclase-cGMP pathway involving K+ATP channels. [source] Hydrothermal synthesis of nano-crystalline BaMoO4 under mild conditions using simple additiveCRYSTAL RESEARCH AND TECHNOLOGY, Issue 2 2010Guangru Tian Abstract Large-scale high-quality BaMoO4 nanocrystals have been synthesized in aqueous solutions under mild conditions with citrate as a simple additive. The crystals have bone-like, spindle-like and wheatear-like morphologies assembled from nanoparticles, nanofibers and have been characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) techniques. The results showed that experimental parameters had great influences on the shape evolution of products. The adjustment of these parameters such as room temperature stirring time, reaction temperature and reaction time of hydrothermal reaction, can lead to obvious morphology changes of products, and the growth mechanism has been proposed. Room-temperature photoluminescence indicated that the as-prepared BaMoO4 nanocrystals had a strong blue emission peak at 481.5 nm. This facile route could be employed to synthesize more promising nanomaterials with interesting self-assembly structures. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] A study of primary nucleation of calcium oxalate monohydrate: II.CRYSTAL RESEARCH AND TECHNOLOGY, Issue 7 2004Effect of urinary species Abstract Kidney stones consist of various organic and inorganic compounds. Calcium oxalate monohydrate (COM) is the main inorganic constituent of kidney stones. However, the mechanisms for the formation of calcium oxalate kidney stones are not well understood. In this regard, there are several hypotheses including nucleation, crystal growth and/or aggregation of formed COM crystals. The effect of some urinary species such as oxalate, calcium, citrate, and protein on nucleation and crystallization characteristics of COM is determined by measuring the weight of formed crystals and their size distributions under different chemical conditions, which simulate the urinary environment. Statistical experimental designs are used to determine the interaction effects among various factors. The data clearly show that oxalate and calcium promote nucleation and crystallization of COM. This is attributed to formation of a thermodynamically stable calcium oxalate monohydrate resulting from supersaturation. Citrate, however, inhibits nucleation and further crystal growth. These results are explained on the basis of the high affinity of citrate to combine with calcium to form soluble calcium citrate complexes. Thus, citrate competes with oxalate ion for binding to calcium cations. These conditions decrease the amount of free calcium ions available to form calcium oxalate crystals. In case of protein (mucin), however, the results suggest that no significant effect could be measured of mucin on nucleation and crystal growth. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Effect of Sildenafil Citrate (Viagra) on Coronary Flow in Normal SubjectsECHOCARDIOGRAPHY, Issue 1 2008Fuminobu Ishikura M.D. Background: The purpose of this study was to evaluate the effect of sildenafil citrate (Viagra) on coronary function in normal subjects. Methods: The study assessed mean blood pressure, left anterior descending coronary artery (LAD) flow, and echocardiographic variables before and 30 and 60 minutes after taking 50 mg of sildenafil citrate. The mean velocity of LAD flow was assessed with Doppler flow imaging. The study subjects were 6 healthy male volunteers (mean age 37 years). Results: The mean velocity of LAD flow increased 60 minutes after taking sildenafil citrate, but there were no other changes. Two volunteers felt mild flashing and one had mild headache during the study. Conclusion: Sildenafil citrate caused vasodilatation in a normal coronary artery without systemic pressure drops. These results suggest that the agent itself did not have negative effects on the heart in normal subjects. [source] Kinetics and Mechanism of Ni(II) Chelation in Model and Real Solutions of Xylem Sap of Quercus ilexELECTROANALYSIS, Issue 22 2007Margarida, Maria Correia, Santos Abstract The kinetics of formation and dissociation of Ni(II) complexes with oxalic and citric acids was studied by cyclic voltammetry in model solutions of xylem sap of Q. ilex (the dominant tree growing on serpentine soils of Northeast Portugal) using representative concentrations, pH and ionic strength. The role of magnesium on complex formation was analyzed from solutions where Mg is present at concentration levels found in the xylem sap of Q. ilex growing on both nonserpentine and serpentine soils. Kinetics studies were also done in diluted solutions of real xylem sap samples, spiked with increasing amounts of magnesium. The values obtained for the apparent rate constants were those anticipated by the proposed model. To test the validity of the methodology and mechanisms, formation rate constants, kf (M,1 s,1) of Ni(II) complexes with citrate and oxalate were evaluated that compare with the values from Eigen mechanism. [source] Manganese speciation in human cerebrospinal fluid using CZE coupled to inductively coupled plasma MSELECTROPHORESIS, Issue 9 2007Bernhard Michalke Dr. Abstract The neurotoxic effects of manganese (Mn) at elevated concentrations are well known. This raises the question, which of the Mn species can cross neural barriers and appear in cerebrospinal fluid (CSF). CSF is the last matrix in a living human organism available for analysis before a compound reaches the brain cells and therefore it is assumed to reflect best the internal exposure of brain tissue to Mn species. A previously developed CE method was modified for separation of albumin, histidine, tyrosine, cystine, fumarate, malate, inorganic Mn, oxalacetate, ,-keto-glutarate, nicotinamide-dinucleotide (NAD), citrate, adenosine, glutathione, and glutamine. These compounds are supposed in the literature to act as potential Mn carriers. In a first attempt, these compounds were analyzed by CZE-UV to check whether they are present in CSF. The CZE-UV method was simpler than the coupled CZE-inductively coupled plasma (ICP)-dynamic reaction cell (DRC)-MS method and it was therefore chosen to obtain a first overview information. In a second step, the coupled method (CZE-ICP-DRC-MS) was used to analyze, in detail, which of the compounds found in CSF by CZE-UV were actually bound to Mn. Finally, 13 Mn species were monitored in CSF samples, most of them being identified: Mn-histidine, Mn-fumarate, Mn-malate, inorganic Mn, Mn-oxalacetate, Mn-,-keto glutarate, Mn-carrying NAD, Mn-citrate and Mn-adenosine. By far the most abundant Mn species was Mn-citrate showing a concentration of 0.7,±,0.13,µg,Mn/L. Interestingly, several other Mn species can be related to the citric acid cycle. [source] Direct determination of gentamicin components by capillary electrophoresis with potential gradient detectionELECTROPHORESIS, Issue 1 2005LingLing Yuan Abstract A simple and fast method was developed to determine non-UV active compounds directly without derivatization. The usefulness of the method was demonstrated by detecting the major components in aminoglycoside antibiotic mixtures using capillary zone electrophoresis with potential gradient detection. Under optimized separation conditions (0.2 mM cetyltrimethylammonium bromide (CTAB), 1 mM ammonium citrate, pH 3.5), gentamicin was separated into three major peaks (C1, C1a, and C2+C2a) within 15 min. This method showed better sensitivity than other capillary electrophoresis (CE) methods for determining underivatized gentamicin. The linear range was from 10 to 500 ppm. Because of its good repeatability and simplicity, this new method could be a good alternative for the current assays given by US Pharmacopoeia and European Pharmacopoeia. [source] Pseudomonas fluorescens orchestrates a fine metabolic-balancing act to counter aluminium toxicityENVIRONMENTAL MICROBIOLOGY, Issue 6 2010Joseph Lemire Summary Aluminium (Al), an environmental toxin, is known to disrupt cellular functions by perturbing iron (Fe) homeostasis. However, Fe is essential for such metabolic processes as the tricarboxylic acid (TCA) cycle and oxidative phosphorylation, the two pivotal networks that mediate ATP production during aerobiosis. To counter the Fe conundrum induced by Al toxicity, Pseudomonas fluorescens utilizes isocitrate lyase and isocitrate dehydrogenase-NADP dependent to metabolize citrate when confronted with an ineffective aconitase provoked by Al stress. By invoking fumarase C, a hydratase devoid of Fe, this microbe is able to generate essential metabolites. To compensate for the severely diminished enzymes like Complex I, Complex II and Complex IV, the upregulation of a H2O-generating NADH oxidase enables the metabolism of citrate, the sole carbon source via a modified TCA cycle. The overexpression of succinyl-CoA synthetase affords an effective route to ATP production by substrate-level phosphorylation in the absence of O2. This fine metabolic balance enables P. fluorescens to survive the dearth of bioavailable Fe triggered by an Al environment, a feature that may have potential applications in bioremediation technologies. [source] A strain isolated from gas oil-contaminated soil displays chemotaxis towards gas oil and hexadecaneENVIRONMENTAL MICROBIOLOGY, Issue 10 2003Mariana P. Lanfranconi Summary In this report we describe the isolation of a strain from soil contaminated with gas oil by taking bacteria from a chemotactic ring on gas oil-containing soft agar plates. Partial 16 S rDNA sequencing of the isolated strain showed 99.1% identity with Flavimonas oryzihabitans. It was not only able to degrade different aliphatic hydrocarbons but it was also chemotactic towards gas oil and hexadecane, as demonstrated by the use of three different chemotaxis methods, such as agarose plug and capillary assays and swarm plate analysis. In addition, the strain was chemotactic to a variety of carbon sources that serve as growth substrates, including glucose, arabinose, mannitol, glycerol, gluconate, acetate, succinate, citrate, malate, lactate and casaminoacids. This is the first report on chemotaxis of a hydrocarbon-degrading bacterium towards a pure alkane, such as hexadecane. The fact that environmental isolates show chemotaxis towards contaminant/s present in the site of isolation suggests that chemotaxis might enhance biodegradation by favouring contact between the degrading microorganism and its substrate. [source] Bioavailability and microbial adaptation to elevated levels of uranium in an acid, organic topsoil forming on an old mine spoilENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2007Erik Jautris Joner Abstract An old mine spoil at a 19th-century mining site with considerable residues of uranium (400,800 mg U/kg) was investigated with respect to U concentrations in soil and plants and tolerance to U in the soil microbial community in order to describe the bioavailability of U. Measurements of soil fractions representing water-soluble U, easily exchangeable U, and U bound to humified organic matter showed that all fractions contained elevated concentrations of U. Plant U concentrations were only 10 times higher at the mine spoil site compared to the reference site (3 mg U/kg vs 0.3 mg U/kg), while the most easily available soil fractions contained 0.18 to 0.86 mg U/kg soil at the mine spoil. An ecotoxicity bioassay using incorporation of [3H]thymidine into the indigenous microbial communities of the two soils in the presence of increasing U concentrations showed that microorganisms at the mining site were sensitive to U but also that they had acquired a substantial tolerance toward U (EC50, the effective concentration reducing activity by 50% of UO2 -citrate was , 120 ,M as compared to 30 ,M in the reference soil). In the assay, more than 40% of the microbial activity was maintained in the presence of 1 ,M UO2-citrate versus 3% in the reference soil. We conclude that U-enriched mining waste can contain sufficiently elevated concentrations of bioavailable U to affect indigenous microorganisms and that bioavailable U imposes a selection pressure that favors the development of a highly uranium-tolerant microbial community, while plant uptake of U remains low. [source] | ||||||||||||||||||||||||||||||||||||||||||||||