Structural and Crystal Chemical Properties of Alkali Rare-earth Double Phosphates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farmer, James Matthew; Boatner, Lynn A.; Chakoumakos, Bryan C.

When appropriately activated, alkali rare-earth double phosphates of the form: M 3RE(PO 4) 2 (where M denotes an alkali metal and RE represents either a rare-earth element or Y or Sc) are of interest for use as inorganic scintillators for radiation detection at relatively long optical emission wavelengths. These compounds exhibit layered crystal structures whose symmetry properties depend on the relative sizes of the rare-earth and alkali-metal cations. Single-crystal X-ray and powder neutron diffraction methods were used here to refine the structures of the series of rare-earth double phosphate compounds: K 3RE(PO 4) 2 with RE = Lu, Er, Ho,more » Dy, Gd, Nd, Ce, plus Y and Sc - as well as the compounds: A 3Lu(PO 4) 2, with A = Rb, and Cs. The double phosphate K 3Lu(PO 4) 2 was reported and structurally refined previously. This material had a hexagonal unit cell at room temperature with the Lu ion six-fold coordinated with oxygen atoms of the surrounding phosphate groups. Additionally two lower-temperature phases were observed for K 3Lu(PO 4) 2. The first phase transition to a monoclinic P21/m phase occurred at ~230 K, and the Lu ion retained its six-fold coordination. The second K 3Lu(PO 4) 2 phase transition occurred at ~130 K. The P21/m space group symmetry was retained, however, one of the phosphate groups rotated to increase the oxygen coordination number of Lu from six to seven. This structure then became isostructural with the room-temperature form of the compound K 3Yb(PO 4) 2 reported here that also exhibits an additional high-temperature phase which occurs at T = 120 °C with a transformation to hexagonal P-3 space group symmetry and a Yb-ion coordination number reduction from seven to six. This latter result was confirmed using EXAFS. The single-crystal growth methods structural systematics, and thermal expansion properties of the present series of alkali rare-earth double phosphates, as determined by X-ray and neutron diffraction methods, are treated

Managing hyperphosphatemia in patients with chronic kidney disease on dialysis with ferric citrate: latest evidence and clinical usefulness

PubMed Central

Fadem, Stephen Z.; Kant, Kotagal S.; Bhatt, Udayan; Sika, Mohammed; Lewis, Julia B.; Negoi, Dana

2015-01-01

Ferric citrate is a novel phosphate binder that allows the simultaneous treatment of hyperphosphatemia and iron deficiency in patients being treated for end-stage renal disease with hemodialysis (HD). Multiple clinical trials in HD patients have uniformly and consistently demonstrated the efficacy of the drug in controlling hyperphosphatemia with a good safety profile, leading the US Food and Drug Administration in 2014 to approve its use for that indication. A concurrent beneficial effect, while using ferric citrate as a phosphate binder, is its salutary effect in HD patients with iron deficiency being treated with an erythropoietin-stimulating agent (ESA) in restoring iron that becomes available for reversing chronic kidney disease (CKD)-related anemia. Ferric citrate has also been shown in several studies to diminish the need for intravenous iron treatment and to reduce the requirement for ESA. Ferric citrate is thus a preferred phosphate binder that helps resolve CKD-related mineral bone disease and iron-deficiency anemia. PMID:26336594

Nitrate reduction by zerovalent iron: effects of formate, oxalate, citrate, chloride, sulfate, borate, and phosphate.

PubMed

Su, Chunming; Puls, Robert W

2004-05-01

Recent studies have shown that zerovalent iron (Fe0) may potentially be used as a chemical medium in permeable reactive barriers (PRBs) for groundwater nitrate remediation; however, the effects of commonly found organic and inorganic ligands in soil and sediments on nitrate reduction by Fe0 have not been well understood. A 25.0 mL nitrate solution of 20.0 mg of N L(-1) (1.43 mM nitrate) was reacted with 1.00 g of Peerless Fe0 at 200 rpm on a rotational shaker at 23 degrees C for up to 120 h in the presence of each of the organic acids (3.0 mM formic, 1.5 mM oxalic, and 1.0 mM citric acids) and inorganic acids (3.0 mM HCl, 1.5 mM H2SO4, 3.0 mM H3BO3, and 1.5 mM H3PO4). These acids provided an initial dissociable H+ concentration of 3.0 mM available for nitrate reduction reactions under conditions of final pH < 9.3. Nitrate reduction rates (pseudo-first-order) increased in the order: H3PO4 < citric acid < H3BO3 < oxalic acid < H2SO4 < formic acid < HCl, ranging from 0.00278 to 0.0913 h(-1), corresponding to surface area normalized rates ranging from 0.126 to 4.15 h(-1) m(-2) mL. Correlation analysis showed a negative linear relationship between the nitrate reduction rates for the ligands and the conditional stability constants for the soluble complexes of the ligands with Fe2+ (R2 = 0.701) or Fe3+ (R2 = 0.918) ions. This sequence of reactivity corresponds also to surface adsorption and complexation of the three organic ligands to iron oxides, which increase in the order formate < oxalate < citrate. The results are also consistent with the sequence of strength of surface complexation of the inorganic ligands to iron oxides, which increases in the order: chloride < sulfate < borate < phosphate. The blockage of reactive sites on the surface of Fe0 and its corrosion products by specific adsorption of the inner-sphere complex forming ligands (oxalate, citrate, sulfate, borate, and phosphate) may be responsible for the decreased nitrate reduction by Fe0 relative to the

The mechanisms of citrate on regulating the distribution of carbon flux in the biosynthesis of uridine 5'-monophosphate by Saccharomyces cerevisiae.

PubMed

Chen, Yong; Li, Shuya; Xiong, Jian; Li, Zhenjiang; Bai, Jianxin; Zhang, Lei; Ye, Qi; Ouyang, Pingkai; Ying, Hanjie

2010-03-01

A whole cell biocatalytic process for uridine 5'-monophosphate (UMP) production from orotic acid by Saccharomyces cerevisiae was developed. The concentration of UMP was increased by 23% when 1 g l(-1) sodium citrate was fed into the broth. Effects of citrate addition on UMP production were investigated. Glucose-6-phosphate pool was elevated by onefold, while FBP and pyruvate were decreased by 42% and 40%, respectively. Organic acid pools such as acetate and succinate were averagely decreased by 30% and 49%. The results demonstrated that manipulation of citrate levels could be used as a novel tool to regulate the metabolic fluxes distribution among glycolysis, pentose phosphate pathway, and TCA cycle.

Calcium-Citrate-Phosphate Solution Injection for In Situ Strontium-90 Immobilization

NASA Astrophysics Data System (ADS)

Fruchter, J. S.; Vermeul, V.; Szecsody, J.; Williams, M. D.; Fritz, B. G.

2010-12-01

Sr-90 present in groundwater and the vadose zone at the Hanford 100N area due to past waste disposal practices has reached the nearby Columbia River, as evidenced by Sr-90 concentrations in near river wells and aquifer tubes and near shore sediments. Sr-90 is currently being remediated by adsorption onto apatite (55 times stronger than Sr-90 adsorption to sediment), followed by incorporation of the Sr-90 into the apatite structure. If the Sr-90 can remain immobilized for 300 years (~ten 29.1-yr half-lives of Sr-90 decay), it will have decayed below regulatory limits to Y-90 and to stable Zr-90. Apatite [Ca10(PO4)6(OH)2] is being precipitated in situ by injection of an aqueous solution of Ca-citrate and Na-phosphate through a series of injection wells spaced 30 ft on center, forming a 300-ft-long permeable reactive barrier. Design criteria for the injection operations were based on 1) amendment volume and mass injected, 2) amendment arrival at adjacent wells, 3) water-level elevation during treatment, and 4) injection rate limitations associated with well plugging. An evaluation of compliance with these injection design criteria was used to assess operational performance and identify candidate wells for supplemental treatment. Injection design criteria were not fully met at 8 of the 16 injection well locations, with the primary deficiency at 4 of 8 locations being the limited vertical extent of Hanford formation treatment due to low-river-stage conditions during the injection. Wells whose extent of treatment did not meet design criteria were recommended for retreatment. Although injection design criteria were not fully met at a significant number of well locations, aqueous performance assessment monitoring data collected to date indicate good barrier performance. Aqueous Sr-90 monitoring in four compliance monitoring wells over a year following the high concentration injections indicates 84% to 95% decrease in Sr-90 concentrations (relative to the low and high end

Clinical trial: the efficacy of alverine citrate/simeticone combination on abdominal pain/discomfort in irritable bowel syndrome--a randomized, double-blind, placebo-controlled study.

PubMed

Wittmann, T; Paradowski, L; Ducrotté, P; Bueno, L; Andro Delestrain, M-C

2010-03-01

Alverine citrate and simeticone combination has been used for almost 20 years in irritable bowel syndrome (IBS), but supportive scientific evidence of efficacy was limited. To evaluate the efficacy of alverine citrate and simeticone combination in patients with IBS-related abdominal pain/discomfort. A total of 412 IBS patients meeting ROME III criteria were included in this double-blind randomized placebo-controlled study if their abdominal pain/discomfort intensity was at least 60 mm on a 0-100 mm visual analogue scale (VAS) during a 2-week run-in treatment-free period. Patients were randomly assigned through the use of Interactive Voice Response System to receive either alverine citrate 60 mg with simeticone 300 mg three times daily or matching placebo for 4 weeks. The full analysis set included 409 patients (71.4% female: mean age: 46.2 +/- 13.9 years). At week 4, alverine citrate and simeticone group had lower VAS scores of abdominal pain/discomfort (median: 40 mm vs. 50 mm, P = 0.047) and higher responder rate (46.8% vs. 34.3%, OR = 1.3; P = 0.01) as compared with placebo group. Patient receiving alverine citrate and simeticone reported greater global symptom improvement compared with those receiving placebo (P = 0.0001). Reported adverse events were similar in both groups. Alverine citrate/simeticone combination was significantly more effective than placebo in relieving abdominal pain/discomfort in patients with IBS.

Ferric Citrate Controls Phosphorus and Delivers Iron in Patients on Dialysis

PubMed Central

Sika, Mohammed; Koury, Mark J.; Chuang, Peale; Schulman, Gerald; Smith, Mark T.; Whittier, Frederick C.; Linfert, Douglas R.; Galphin, Claude M.; Athreya, Balaji P.; Nossuli, A. Kaldun Kaldun; Chang, Ingrid J.; Blumenthal, Samuel S.; Manley, John; Zeig, Steven; Kant, Kotagal S.; Olivero, Juan Jose; Greene, Tom; Dwyer, Jamie P.

2015-01-01

Patients on dialysis require phosphorus binders to prevent hyperphosphatemia and are iron deficient. We studied ferric citrate as a phosphorus binder and iron source. In this sequential, randomized trial, 441 subjects on dialysis were randomized to ferric citrate or active control in a 52-week active control period followed by a 4-week placebo control period, in which subjects on ferric citrate who completed the active control period were rerandomized to ferric citrate or placebo. The primary analysis compared the mean change in phosphorus between ferric citrate and placebo during the placebo control period. A sequential gatekeeping strategy controlled study-wise type 1 error for serum ferritin, transferrin saturation, and intravenous iron and erythropoietin-stimulating agent usage as prespecified secondary outcomes in the active control period. Ferric citrate controlled phosphorus compared with placebo, with a mean treatment difference of −2.2±0.2 mg/dl (mean±SEM) (P<0.001). Active control period phosphorus was similar between ferric citrate and active control, with comparable safety profiles. Subjects on ferric citrate achieved higher mean iron parameters (ferritin=899±488 ng/ml [mean±SD]; transferrin saturation=39%±17%) versus subjects on active control (ferritin=628±367 ng/ml [mean±SD]; transferrin saturation=30%±12%; P<0.001 for both). Subjects on ferric citrate received less intravenous elemental iron (median=12.95 mg/wk ferric citrate; 26.88 mg/wk active control; P<0.001) and less erythropoietin-stimulating agent (median epoetin-equivalent units per week: 5306 units/wk ferric citrate; 6951 units/wk active control; P=0.04). Hemoglobin levels were statistically higher on ferric citrate. Thus, ferric citrate is an efficacious and safe phosphate binder that increases iron stores and reduces intravenous iron and erythropoietin-stimulating agent use while maintaining hemoglobin. PMID:25060056

Phosphate inhibits in vitro Fe3+ loading into transferrin by forming a soluble Fe(III)-phosphate complex: a potential non-transferrin bound iron species.

PubMed

Hilton, Robert J; Seare, Matthew C; Andros, N David; Kenealey, Zachary; Orozco, Catalina Matias; Webb, Michael; Watt, Richard K

2012-05-01

In chronic kidney diseases, NTBI can occur even when total iron levels in serum are low and transferrin is not saturated. We postulated that elevated serum phosphate concentrations, present in CKD patients, might disrupt Fe(3+) loading into apo-transferrin by forming Fe(III)-phosphate species. We report that phosphate competes with apo-transferrin for Fe(3+) by forming a soluble Fe(III)-phosphate complex. Once formed, the Fe(III)-phosphate complex is not a substrate for donating Fe(3+) to apo-transferrin. Phosphate (1-10mM) does not chelate Fe(III) from diferric transferrin under the conditions examined. Complexed forms of Fe(3+), such as iron nitrilotriacetic acid (Fe(3+)-NTA), and Fe(III)-citrate are not susceptible to this phosphate complexation reaction and efficiently deliver Fe(3+) to apo-transferrin in the presence of phosphate. This reaction suggests that citrate might play an important role in protecting against Fe(III), phosphate interactions in vivo. In contrast to the reactions of Fe(3+) and phosphate, the addition of Fe(2+) to a solution of apo-transferrin and phosphate lead to rapid oxidation and deposition of Fe(3+) into apo-transferrin. These in vitro data suggest that, in principle, elevated phosphate concentrations can influence the ability of apo-transferrin to bind iron, depending on the oxidation state of the iron. Copyright © 2012 Elsevier Inc. All rights reserved.

Double coating protection of Nd-Fe-B magnets: Intergranular phosphating treatment and copper plating

NASA Astrophysics Data System (ADS)

Zheng, Jingwu; Chen, Haibo; Qiao, Liang; Lin, Min; Jiang, Liqiang; Che, Shenglei; Hu, Yangwu

2014-12-01

In this work, a double coating protection technique of phosphating treatment and copper plating was made to improve the corrosion resistance of sintered Nd-Fe-B magnets. In other words, the intergranular region of sintered Nd-Fe-B is allowed to generate passive phosphate conversion coating through phosphating treatment, followed by the copper coating on the surface of sintered Nd-Fe-B. The morphology and corrosion resistance of the phosphated sintered Nd-Fe-B were observed using SEM and electrochemical method respectively. The phosphate conversion coating was formed more preferably on the intergranular region of sintered Nd-Fe-B than on the main crystal region; just after a short time of phosphating treatment, the intergranular region of sintered Nd-Fe-B has been covered by the phosphate conversion coating and the corrosion resistance is significantly improved. With the synergistic protection of the intergranular phosphorization and the followed copper electrodeposition, the corrosion resistance of the sintered Nd-Fe-B is significantly better than that with a single phosphate film or single plating protection.

Splenda® improves tolerance of oral potassium citrate supplementation for prevention of stone formation: results of a randomized double-blind trial.

PubMed

Mechlin, Clay; Kalorin, Carmin; Asplin, John; White, Mark

2011-09-01

Oral citrate supplements have been shown to decrease kidney stone recurrence rates in both laboratory and clinical studies. The taste of the citrate supplements, however, is poor, and long-term compliance is low. Our objective was to determine if Splenda(®) added to potassium citrate (KCit) improves palatability without changing 24-hour urine parameters. 12 subjects were randomly assigned to receive either KCit alone for 3 days or KCit + Splenda in a double-blind trial. The 24-hour urine collections were performed before and after 3 days of therapy. After 1 week, the two groups switched treatments. After each treatment, a visual analog taste scale was completed to gauge the taste and palatability. The 24-hour urine parameters of kidney stone risk factors were compared between groups. The primary end points were to determine whether Splenda improved palatability of citrate supplementation and whether it altered 24-hour urine parameters. Taste was judged to be 2.5 ± 0.9 points better in the Splenda + KCit compared with KCit alone (P=0.02). The 24-hour Cit, K, and pH were significantly higher in the KCit and KCit + Splenda groups compared with baseline, but not significantly different from each other. Splenda significantly improves the palatability of KCit therapy and does not alter the beneficial effects of KCit on 24-hour urine Cit, K, or pH. The addition of Splenda altered the average taste score from one that might prohibit compliance to one that would not.

Adsorption of phosphate from seawater on calcined MgMn-layered double hydroxides.

PubMed

Chitrakar, Ramesh; Tezuka, Satoko; Sonoda, Akinari; Sakane, Kohji; Ooi, Kenta; Hirotsu, Takahiro

2005-10-01

Adsorptive properties of MgMn-3-300 (MgMn-type layered double hydroxide with Mg/Mn mole ratio of 3, calcined at 300 degrees C) for phosphate were investigated in phosphate-enriched seawater with a concentration of 0.30 mg-P/dm3. It showed the highest phosphate uptake from the seawater among the inorganic adsorbents studied (hydrotalcite, calcined hydrotalcite, activated magnesia, hydrous aluminum oxide, manganese oxide (delta-MnO2)). The phosphate uptake by MgMn-3-300 reached 7.3 mg-P/g at an adsorbent/solution ratio of 0.05 g/2 dm3. The analyses of the uptakes of other constituents (Na+, K+, Ca(+, Cl-, and SO(2-)4) of seawater showed that the adsorbent had a markedly high selectivity for the adsorption of phosphate ions. Effects of initial phosphate concentration, temperature, pH, and salinity on phosphate uptake were investigated in detail by a batch method. The phosphate uptake increased slightly with an increase in the adsorption temperature. The adsorption isotherm followed Freundlich's equation with constants of logK(F)=1.25 and 1/n=0.65, indicating that it could effectively remove phosphate even from a solution of markedly low phosphate concentration as well as with large numbers of coexisting ions. The pH dependence showed a maximum phosphate uptake around pH 8.5. The pH dependence curve suggested that selective phosphate adsorption progresses mainly by the ion exchange of HPO(2-)4. The study on the effect of salinity suggested the presence of two kinds of adsorption sites in the adsorbent: one nonspecific site with weak interaction and one specific site with strong interaction. The effective desorption of phosphate could be achieved using a mixed solution of 5 M NaCl + 0.1 M NaOH (1 M = 1 mol/dm3), with negligible dissolution of adsorbent. The adsorbent had high chemical stability against the adsorption/desorption cycle; it kept a good phosphate uptake even after the repetition of the seventh cycle.

The effect of organic ligands on the crystallinity of calcium phosphate

NASA Astrophysics Data System (ADS)

van der Houwen, Jacqueline A. M.; Cressey, Gordon; Cressey, Barbara A.; Valsami-Jones, Eugenia

2003-03-01

Calcium phosphate phases precipitated under critical supersaturation were identified and studied in detail using X-ray powder diffraction, electron probe microanalysis, infrared spectroscopy (IR) and transmission electron microscopy. These synthetic calcium phosphates formed by spontaneous precipitation at pH 7, 25°C and 0.1 M ionic strength (NaCl as the background electrolyte). The combination of several methods allowed detailed characterisation of the calcium phosphates. The purpose of the work was to assess the influence of carboxylate ligands, specifically acetate and citrate, on the quality of the calcium phosphate precipitate. All precipitates were identified as non-stoichiometric, calcium-deficient hydroxylapatites (HAPs), containing carbonate, HPO 42-, sodium and chloride impurities. No other phases were found to be present in any of the precipitates. The presence of citrate resulted in a decrease in crystal size and a higher degree of apatite lattice imperfection in the precipitated HAP. Furthermore, IR spectroscopy showed a higher amount of carbonate present in that HAP, compared with the ones formed in the control and acetate experiments. An additional absorption band, in the infrared spectrum of the HAP formed in the presence of citrate, was observed at 1570 cm -1; this is interpreted as carboxyl groups bound to HAP.

Effect of clomifene citrate plus metformin and clomifene citrate plus placebo on induction of ovulation in women with newly diagnosed polycystic ovary syndrome: randomised double blind clinical trial.

PubMed

Moll, Etelka; Bossuyt, Patrick M M; Korevaar, Johanna C; Lambalk, Cornelis B; van der Veen, Fulco

2006-06-24

To compare the effectiveness of clomifene citrate plus metformin and clomifene citrate plus placebo in women with newly diagnosed polycystic ovary syndrome. Randomised clinical trial. Multicentre trial in 20 Dutch hospitals. 228 women with polycystic ovary syndrome. Clomifene citrate plus metformin or clomifene citrate plus placebo. The primary outcome measure was ovulation. Secondary outcome measures were ongoing pregnancy, spontaneous abortion, and clomifene resistance. 111 women were allocated to clomifene citrate plus metformin (metformin group) and 114 women were allocated to clomifene citrate plus placebo (placebo group). The ovulation rate in the metformin group was 64% compared with 72% in the placebo group, a non-significant difference (risk difference - 8%, 95% confidence interval - 20% to 4%). There were no significant differences in either rate of ongoing pregnancy (40% v 46%; - 6%, - 20% to 7%) or rate of spontaneous abortion (12% v 11%; 1%, - 7% to 10%). A significantly larger proportion of women in the metformin group discontinued treatment because of side effects (16% v 5%; 11%, 5% to 16%). Metformin is not an effective addition to clomifene citrate as the primary method of inducing ovulation in women with polycystic ovary syndrome. Current Controlled Trials ISRCTN55906981 [controlled-trials.com].

Effect of clomifene citrate plus metformin and clomifene citrate plus placebo on induction of ovulation in women with newly diagnosed polycystic ovary syndrome: randomised double blind clinical trial

PubMed Central

Moll, Etelka; Bossuyt, Patrick M M; Korevaar, Johanna C; Lambalk, Cornelis B; van der Veen, Fulco

2006-01-01

Objective To compare the effectiveness of clomifene citrate plus metformin and clomifene citrate plus placebo in women with newly diagnosed polycystic ovary syndrome. Design Randomised clinical trial. Setting Multicentre trial in 20 Dutch hospitals. Participants 228 women with polycystic ovary syndrome. Interventions Clomifene citrate plus metformin or clomifene citrate plus placebo. Main outcome measure The primary outcome measure was ovulation. Secondary outcome measures were ongoing pregnancy, spontaneous abortion, and clomifene resistance. Results 111 women were allocated to clomifene citrate plus metformin (metformin group) and 114 women were allocated to clomifene citrate plus placebo (placebo group). The ovulation rate in the metformin group was 64% compared with 72% in the placebo group, a non-significant difference (risk difference - 8%, 95% confidence interval - 20% to 4%). There were no significant differences in either rate of ongoing pregnancy (40% v 46%; - 6%, - 20% to 7%) or rate of spontaneous abortion (12% v 11%; 1%, - 7% to 10%). A significantly larger proportion of women in the metformin group discontinued treatment because of side effects (16% v 5%; 11%, 5% to 16%). Conclusion Metformin is not an effective addition to clomifene citrate as the primary method of inducing ovulation in women with polycystic ovary syndrome. Trial registration Current Controlled Trials ISRCTN55906981 [controlled-trials.com]. PMID:16769748

Double Stokes-Mueller polarimetry in KTP (Potassium Titanyl Phosphate) crystal

NASA Astrophysics Data System (ADS)

Shaji, Chitra; S B, Sruthil Lal; Sharan, Alok

2017-04-01

Ultra-structural properties of material are being probed by Double Stokes-Mueller polarimetry (DSMP) technique. It makes use of higher dimensions of Stokes vector (9 X 1) and Mueller matrix (4 X9) to characterize the nonlinear optical properties of a material. Second harmonic generation (SHG) at 532nm using 1064nm as fundamental cw beam from Nd: YAG laser in type II phase matched KTP (Potassium Titanyl Phosphate) crystal is studied using DSMP. The experimental measurements for determining double Mueller matrix are carried out in the ``Polarization In Polarization Out'' (PIPO) arrangement. Nine input polarization states are incident on the sample and the linear Stokes vector of the emerging light from the sample is measured. The KTP crystal is oriented such that the SHG signal efficiency at the incident horizontal and vertical polarizations is high as compared to diagonal polarization states. The susceptibility tensor components and the phase difference between them at this orientation are determined from the double Mueller matrix elements. These determined values give information regarding the crystal axis orientations. To our knowledge, this is the first report of the use of DSMP technique to determine the crystal orientations of a biaxial crystal.

Phosphate recovery from wastewater using engineered superparamagnetic particles modified with layered double hydroxide ion exchangers.

PubMed

Drenkova-Tuhtan, Asya; Mandel, Karl; Paulus, Anja; Meyer, Carsten; Hutter, Frank; Gellermann, Carsten; Sextl, Gerhard; Franzreb, Matthias; Steinmetz, Heidrun

2013-10-01

An innovative nanocomposite material is proposed for phosphate recovery from wastewater using magnetic assistance. Superparamagnetic microparticles modified with layered double hydroxide (LDH) ion exchangers of various compositions act as phosphate adsorbers. Magnetic separation and chemical regeneration of the particles allows their reuse, leading to the successful recovery of phosphate. Based upon the preliminary screening of different LDH ion exchanger modifications for phosphate selectivity and uptake capacity, MgFe-Zr LDH coated magnetic particles were chosen for further characterization and application. The adsorption kinetics of phosphate from municipal wastewater was studied in dependence with particle concentration, contact time and pH. Adsorption isotherms were then determined for the selected particle system. Recovery of phosphate and regeneration of the particles was examined via testing a variety of desorption solutions. Reusability of the particles was demonstrated for 15 adsorption/desorption cycles. Adsorption in the range of 75-97% was achieved in each cycle after 1 h contact time. Phosphate recovery and enrichment was possible through repetitive application of the desorption solution. Finally, a pilot scale experiment was carried out by treating 125 L of wastewater with the particles in five subsequent 25 L batches. Solid-liquid separation on this scale was carried out with a high-gradient magnetic filter (HGMF). Copyright © 2013 Elsevier Ltd. All rights reserved.

Randomised, double-blind, comparative study to evaluate the efficacy and safety of ganaton (itopride hydrochloride) and mosapride citrate in the management of functional dyspepsia.

PubMed

Amarapurkar, Deepak N; Rane, Priya

2004-12-01

Prokinetic agents like itopride hydrochloride and mosapride citrate are commonly used in the management of functional dyspepsia. However, in a recently conducted international, multicentric study, efficacy of 3 different regimens of mosapride was shown to be comparable to placebo. The objective of this phase 4 randomised, double blind, prospective study was to compare the efficacy and safety of ganaton (itopride hydrochloride) and mosapride citrate in the management of functional dyspepsia among patients attending the gastroenterology outpatient department of a tertiary care hospital. Ganaton 50 mg or mosapride citrate 5 mg three times daily before meals for a period of 2 weeks was administered orally. Thirty functional dyspepsia patients in each group (total = 60) were randomised to receive itopride hydrochloride or mosapride citrate treatment for 2 weeks. In itopride versus mosapride groups, global efficacy as judged by patients was excellent in 17 versus 9 (p < 0.05) and poor in 0 versus 3 (p < 0.05). In itopride versus mosapride group global efficacy as judged by physician was excellent in 24 (80%) versus 15 (50%) and poor in 0 (0%) versus 3 (10%) patients respectively. The global efficacy was rated as excellent to good in significantly (p < 0.05) more number of patients in itopride (93.3%) group as compared to mosapride (63.33 %) group. None of the patients reported any adverse events with itopride treatment. In the mosapride group 5 patients (16.7%) reported adverse events. Two patients (6.7%) were withdrawn from mosapride treatment due to adverse events. The physician rated global tolerability ofitopride versus mosapride treatment as excellent in 23 (76.7%) versus 8 (26.7%) (p < 0.05) and poor in 0 (0%) versus 6 (20%) patients respectively. It may be concluded that ganaton (itopride hydrochloride) is superior in efficacy and safety over mosapride citrate in the management of functional dyspepsia.

Gastrointestinal citrate absorption in nephrolithiasis

NASA Technical Reports Server (NTRS)

Fegan, J.; Khan, R.; Poindexter, J.; Pak, C. Y.

1992-01-01

Gastrointestinal absorption of citrate was measured in stone patients with idiopathic hypocitraturia to determine if citrate malabsorption could account for low urinary citrate. Citrate absorption was measured directly from recovery of orally administered potassium citrate (40 mEq.) in the intestinal lavage fluid, using an intestinal washout technique. In 7 stone patients citrate absorption, serum citrate levels, peak citrate concentration in serum and area under the curve were not significantly different from those of 7 normal subjects. Citrate absorption was rapid and efficient in both groups, with 96 to 98% absorbed within 3 hours. The absorption of citrate was less efficient from a tablet preparation of potassium citrate than from a liquid preparation, probably due to a delayed release of citrate from wax matrix. However, citrate absorption from solid potassium citrate was still high at 91%, compared to 98% for a liquid preparation. Thus, hypocitraturia is unlikely to be due to an impaired gastrointestinal absorption of citrate in stone patients without overt bowel disease.

Anionic surfactant enhanced phosphate desorption from Mg/Al-layered double hydroxides by micelle formation.

PubMed

Shimamura, Akihiro; Jones, Mark I; Metson, James B

2013-12-01

Desorption of interlayer hydrogen phosphate (HPO4) from hydrogen phosphate intercalated Mg/Al-layered double hydroxide (LDH-HPO4) by anion exchange with surfactant anions has been investigated under controlled conditions. Three types of surfactant, Dodecylbenzenesulphonate (DBS), Dodecylsulphate (DS) and 1-Octanesulphonate (OS), anions were used for intercalation experiments over a range of concentrations, and for all solutions, it was shown that the desorption of hydrogen phosphate is enhanced at concentrations close to the critical micelle concentration (CMC). Intercalation of the surfactant anions into LDH-HPO4 was confirmed by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning electron microscopy (SEM). More than 90% removal of the hydrogen phosphate was achieved at CMC. Repeat adsorption tests to investigate recyclability showed that desorption with 0.005 M DBS improved subsequent phosphate re-adsorption, allowing around 90% of the original adsorption over three cycles. This is much higher than when desorption was conducted using either Na2CO3 or NaCl-NaOH solutions, even at much higher concentrations. This study suggests potential economic and environmental advantages in using these surfactants in improving the cycling performance of LDH materials as absorbents for clean-up of water systems. Copyright © 2013 Elsevier Inc. All rights reserved.

Influence of glucagon or 5-(tetradecyloxy)-2-furoic acid on binding to mitochondria and phosphorylation of ATP-citrate lyase.

PubMed

Janski, A M; Cornell, N W

1982-02-01

To study the binding to mitochondria and the phosphorylation of ATP-citrate lyase (EC 4.1.3.8), isolated rat hepatocytes were fractionated by exposure to digitonin. After incubation of hepatocytes with the hypolipidemic agent 5-(tetradecyloxy)-2-furoic acid, which decreases the cellular CoA, the amount of bound ATP-citrate lyase was increased, but the content of acid-stable phosphate in the enzyme was diminished. Glucagon, in contrast, decreased the amount of bound enzyme but increased phosphorylation. This inverse relationship might indicate either that the bound ATP-citrate lyase is less readily phosphorylated or that the phosphorylated enzyme binds less readily to mitochondria.

Acute and 3-month effects of microcrystalline hydroxyapatite, calcium citrate and calcium carbonate on serum calcium and markers of bone turnover: a randomised controlled trial in postmenopausal women.

PubMed

Bristow, Sarah M; Gamble, Greg D; Stewart, Angela; Horne, Lauren; House, Meaghan E; Aati, Opetaia; Mihov, Borislav; Horne, Anne M; Reid, Ian R

2014-11-28

Ca supplements are used for bone health; however, they have been associated with increased cardiovascular risk, which may relate to their acute effects on serum Ca concentrations. Microcrystalline hydroxyapatite (MCH) could affect serum Ca concentrations less than conventional Ca supplements, but its effects on bone turnover are unclear. In the present study, we compared the acute and 3-month effects of MCH with conventional Ca supplements on concentrations of serum Ca, phosphate, parathyroid hormone and bone turnover markers. We randomised 100 women (mean age 71 years) to 1 g/d of Ca as citrate or carbonate (citrate-carbonate), one of two MCH preparations, or a placebo. Blood was sampled for 8 h after the first dose, and after 3 months of daily supplementation. To determine whether the acute effects changed over time, eight participants assigned to the citrate dose repeated 8 h of blood sampling at 3 months. There were no differences between the citrate and carbonate groups, or between the two MCH groups, so their results were pooled. The citrate-carbonate dose increased ionised and total Ca concentrations for up to 8 h, and this was not diminished after 3 months. MCH increased ionised Ca concentrations less than the citrate-carbonate dose; however, it raised the concentrations of phosphate and the Ca-phosphate product. The citrate-carbonate and MCH doses produced comparable decreases in bone resorption (measured as serum C-telopeptide (CTX)) over 8 h and bone turnover (CTX and procollagen type-I N-terminal propeptide) at 3 months. These findings suggest that Ca preparations, in general, produce repeated sustained increases in serum Ca concentrations after ingestion of each dose and that Ca supplements with smaller effects on serum Ca concentrations may have equivalent efficacy in suppressing bone turnover.

A randomized controlled trial of clomifene citrate, metformin, and pioglitazone versus letrozole, metformin, and pioglitazone for clomifene-citrate-resistant polycystic ovary syndrome.

PubMed

El-khayat, Waleed; Abdel Moety, Ghada; Al Mohammady, Maged; Hamed, Dalia

2016-02-01

To examine the efficacy of clomifene citrate, metformin, and pioglitazone versus letrozole, metformin, and pioglitazone among women with polycystic ovary syndrome (PCOS) resistant to clomifene citrate. A prospective double-blind randomized controlled trial of women younger than 40 years who had primary/secondary infertility associated with PCOS and had not ovulated in response to clomifene citrate regimens previously was conducted at a center in Cairo, Egypt, between August 1, 2013, and December 31, 2014. Computer-generated random number tables and opaque envelopes were used to assign participants to group A or group B. Participants allocated to group A received 100mg clomifene citrate daily for 5 days from the third day of the menstrual cycle, whereas those in group B received 5mg letrozole daily in the same regimen. All patients received 850 mg metformin and 15 mg pioglitazone for 10 days from the first day of the menstrual cycle. The primary outcome was cumulative ovulation rate. Analyses were by intention to treat. Fifty women were assigned to each group. Ovulation occurred in 108 (92.3%) of 117 cycles in group A and 93 (86.9%) of 107 cycles in Group B (P=0.184). Combined treatment with letrozole, metformin, and pioglitazone was efficacious among women with PCOS resistant to clomifene citrate. ClinicalTrials.gov: NCT01909141. Copyright © 2015 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Enhancing phosphate adsorption by Mg/Al layered double hydroxide functionalized biochar with different Mg/Al ratios.

PubMed

Li, Ronghua; Wang, Jim J; Zhou, Baoyue; Awasthi, Mukesh Kumar; Ali, Amjad; Zhang, Zengqiang; Gaston, Lewis A; Lahori, Altaf Hussain; Mahar, Amanullah

2016-07-15

Mg/Al ratio plays a significant role for anion adsorption by Mg/Al-layered double hydroxides (Mg/Al-LDHs) modified biochar. In this study, Mg/Al-LDHs biochar with different Mg/Al ratios (2, 3, 4) were prepared by co-precipitation for phosphate removal from aqueous solution. Factors on phosphate adsorption including Mg/Al ratio, pH, and the presence of other inorganic anions were investigated through batch experiments. Increasing Mg/Al ratio in the Mg/Al-LDHs biochar composites generally enhanced phosphate adsorption with Langmuir adsorption maximum calculated at 81.83mg phosphorous (P) per gram of 4:1Mg/Al-LDHs biochar at pH3.0. The adsorption process was best described by the pseudo-second-order kinetic model. Solution pH had greater effects on the phosphate adsorption by Mg/Al LDHs biochar composites with lower Mg/Al ratios. The presence of other inorganic anions decreased the phosphate adsorption efficiency in the order of F(-) > SO4(2-) > NO2(-) >Cl(-). Phosphate adsorption mechanism involves ion exchange, electrostatic attraction and surface inner-sphere complex formation. Overall, Mg/Al-LDHs biochar composites offer a potential alternative of carbon-based adsorbent for phosphate removal from aqueous solution. Copyright © 2016 Elsevier B.V. All rights reserved.

Reduction of costs for anemia-management drugs associated with the use of ferric citrate

PubMed Central

Thomas, Anila; Peterson, Leif E

2014-01-01

Background Ferric citrate is a novel phosphate binder which has the potential to reduce usage of erythropoietin-stimulating agents (ESAs) and intravenous (IV) iron used for anemia management during hemodialysis (HD) among patients with end-stage renal disease (ESRD). Currently, the potential health care cost savings on a national scale due to the use of ferric citrate in ESRD are undetermined. Methods Per-patient-per-year costs of ESAs (Epogen® and Aranesp® [Amgen Inc., CA, USA]) and IV iron (Venofer® [American Regent, Inc., NY, USA] and Ferrlecit® [Sanofi US, Bridgewater, NJ, USA]) were based on RED BOOK™ (Truven Health Analytics New York, NY, USA) costs combined with the Centers for Medicare and Medicaid Services (CMS) base rate and actual usage in 2011 for the four drugs. The annual number of outpatients undergoing HD in the US was based on frequencies reported by the USRDS (United States Renal Data System). Monte Carlo uncertainty analysis was performed to determine total annual costs and cost reduction based on ferric citrate usage. Results Total annual cost of ESAs and IV iron for anemia management in ESRD determined by Monte Carlo analysis assuming CMS base rate value was 5.127 (3.664–6.260) billion USD. For actual utilization in 2011, total annual cost of ESAs and IV iron was 3.981 (2.780–4.930) billion USD. If ferric citrate usage reduced ESA utilization by 20% and IV iron by 40%, then total cost would be reduced by 21.2% to 4.038 (2.868–4.914) billion USD for the CMS base rate, and by 21.8% to 3.111 (2.148–3.845) billion USD, based on 2011 actual utilization. Conclusion It is likely that US health care costs for anemia-management drugs associated with ESRD among HD patients can be reduced by using ferric citrate as a phosphate binder. PMID:24899820

Low-field magnetoresistance up to 400 K in double perovskite Sr{sub 2}FeMoO{sub 6} synthesized by a citrate route

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harnagea, L., E-mail: harnagealuminita@gmail.com; Jurca, B.; Physical Chemistry Department, University of Bucharest, 4-12 Bd. Elisabeta, 030018 Bucharest

2014-03-15

A wet-chemistry technique, namely the citrate route, has been used to prepare high-quality polycrystalline samples of double perovskite Sr{sub 2}FeMoO{sub 6}. We report on the evolution of magnetic and magnetoresistive properties of the synthesized samples as a function of three parameters (i) the pH of the starting solution, (ii) the decomposition temperature of the citrate precursors and (iii) the sintering conditions. The low-field magnetoresistance (LFMR) value of our best samples is as high as 5% at room temperature for an applied magnetic field of 1 kOe. Additionally, the distinguishing feature of these samples is the persistence of LFMR, with amore » reasonably large value, up to 400 K which is a crucial parameter for any practical application. Our study indicates that the enhancement of LFMR observed is due to a good compromise between the grain size distribution and their magnetic polarization. -- Graphical abstract: The microstructure (left panel) and corresponding low-field magnetoresistance of one of the Sr{sub 2}FeMoO{sub 6} samples synthesized in the course of this work. Highlights: • Samples of Sr{sub 2}FeMoO{sub 6} are prepared using a citrate route under varying conditions. • Magnetoresistive properties are improved and optimized. • Low-field magnetoresitence values as large as 5% at 300 K/1 kOe are reported. • Persistence of low-field magnetoresistance up to 400 K.« less

Gender and chronological age affect erythrocyte membrane oxidative indices in citrate phosphate dextrose adenine-formula 1 (CPDA-1) blood bank storage condition.

PubMed

Erman, Hayriye; Aksu, Uğur; Belce, Ahmet; Atukeren, Pınar; Uzun, Duygu; Cebe, Tamer; Kansu, Ahmet D; Gelişgen, Remisa; Uslu, Ezel; Aydın, Seval; Çakatay, Ufuk

2016-07-01

It is well known that in vitro storage lesions lead to membrane dysfunction and decreased number of functional erythrocytes. As erythrocytes get older, in storage media as well as in peripheral circulation, they undergo a variety of biochemical changes. In our study, the erythrocytes with different age groups in citrate phosphate dextrose adenine-formula 1 (CPDA-1) storage solution were used in order to investigate the possible effect of gender factor on oxidative damage. Oxidative damage biomarkers in erythrocyte membranes such as ferric reducing antioxidant power, pro-oxidant-antioxidant balance, protein-bound advance glycation end products, and sialic acid were analyzed. Current study reveals that change in membrane redox status during blood-bank storage condition also depends on both gender depended homeostatic factors and the presence of CPDA-1. During the storage period in CPDA-1, erythrocytes from the male donors are mostly affected by free radical-mediated oxidative stress but erythrocytes obtained from females are severely affected by glyoxidative stress.

Bio-solid-State processes for synthesis of Li-Fe-phosphate.

PubMed

Kim, Hyoung-Bum; Park, Byungno; Lee, Insung; Roh, Yul

2008-10-01

Lithium-Fe-phosphates have become of great interest as storage cathodes for rechargeable Li-batteries because of their high density, environmental friendliness, and safety. The objective of this study was to examine bio-solid-state synthesis of LiFePO4 by microbial processes at room temperature. The microbial reduction of Fe(III)-citrate using an organic carbon, glucose, as an electron donor in the presence of NaHPO4 and lithium that resulted in the formation of Li-substituted iron phosphate. Our studies showed that bacteria enriched from inter-tidal flat sediments, designated as Haejae-1, synthesized Li-substituted iron phosphate. Characterization by X-ray diffraction showed the reduction of Fe(III)-citrate in the presence of NaHPO4 and LiCl2 resulted in the precipitation of Li-substituted vivianite [Li(x)Fe(3-x)(PO4)2 x 8H2O]. SEM-EDX, FTIR, and ESCA analyses showed the chemical composition of the synthesized phases was Li, Fe, P, C, and O. Based on the chemical and physical structure of the mineral, the novel bio-nano-material may be potentially useful to the development of energy storage materials.

Citrate Inhibition-Resistant Form of 6-Phosphofructo-1-Kinase from Aspergillus niger

PubMed Central

Mlakar, Tina; Legiša, Matic

2006-01-01

Two forms of Aspergillus niger 6-phosphofructo-1-kinase (PFK1) have been described recently, the 85-kDa native enzyme and 49-kDa shorter fragment that is formed from the former by posttranslational modification. So far, kinetic characteristics have never been determined on the enzyme purified to near homogeneity. For the first time, kinetic parameters were determined for individual enzymes with respect to citrate inhibition. The native 85-kDa enzyme was found to be moderately inhibited by citrate, with the Ki value determined to be 1.5 mM, in the system with 5 mM Mg2+ ions, while increasing magnesium concentrations relieved the negative effect of citrate. An identical inhibition coefficient was determined also in the presence of ammonium ions, although ammonium acted as a strong activator of enzyme activity. On the other hand, the shorter fragment of PFK1 proved to be completely resistant to inhibition by citrate. Allosteric citrate binding sites were most probably lost after the truncation of the C-terminal part of the native protein, in which region some binding sites for inhibitor are known to be located. At near physiological conditions, characterized by low fructose-6-phosphate concentrations, a much higher efficiency of the shorter fragment was observed during an in vitro experiment. Since the enzyme became more susceptible to the positive control by specific ligands, while the negative control was lost after posttranslational modification, the shorter PFK1 fragment seems to be the enzyme most responsible for generating undisturbed metabolic flow through glycolysis in A. niger cells. PMID:16820438

citrate inhibition-resistant form of 6-phosphofructo-1-kinase from Aspergillus niger.

PubMed

Mlakar, Tina; Legisa, Matic

2006-07-01

Two forms of Aspergillus niger 6-phosphofructo-1-kinase (PFK1) have been described recently, the 85-kDa native enzyme and 49-kDa shorter fragment that is formed from the former by posttranslational modification. So far, kinetic characteristics have never been determined on the enzyme purified to near homogeneity. For the first time, kinetic parameters were determined for individual enzymes with respect to citrate inhibition. The native 85-kDa enzyme was found to be moderately inhibited by citrate, with the Ki value determined to be 1.5 mM, in the system with 5 mM Mg2+ ions, while increasing magnesium concentrations relieved the negative effect of citrate. An identical inhibition coefficient was determined also in the presence of ammonium ions, although ammonium acted as a strong activator of enzyme activity. On the other hand, the shorter fragment of PFK1 proved to be completely resistant to inhibition by citrate. Allosteric citrate binding sites were most probably lost after the truncation of the C-terminal part of the native protein, in which region some binding sites for inhibitor are known to be located. At near physiological conditions, characterized by low fructose-6-phosphate concentrations, a much higher efficiency of the shorter fragment was observed during an in vitro experiment. Since the enzyme became more susceptible to the positive control by specific ligands, while the negative control was lost after posttranslational modification, the shorter PFK1 fragment seems to be the enzyme most responsible for generating undisturbed metabolic flow through glycolysis in A. niger cells.

Nanoscale observations of the effect of citrate on calcium oxalate precipitation on calcite surfaces.

NASA Astrophysics Data System (ADS)

Burgos-Cara, Alejandro; Ruiz-Agudo, Encarnacion; Putnis, Christine V.

2016-04-01

Calcium oxalate (CaC2O4ṡxH2O) minerals are naturally occurring minerals found in fossils, plants, kidney stones and is a by-product in some processes such as paper, food and beverage production [1,2]. In particular, calcium oxalate monohydrate phase (COM) also known as whewellite (CaC2O4ṡH2O), is the most frequently reported mineral phase found in urinary and kidney stones together with phosphates. Organic additives are well known to play a key role in the formation of minerals in both biotic and abiotic systems, either facilitating their precipitation or hindering it. In this regard, recent studies have provided direct evidence demonstrating that citrate species could enhance dissolution of COM and inhibit their precipitation. [3,4] The present work aims at evauate the influence of pH, citrate and oxalic acid concentrations in calcium oxalate precipitation on calcite surfaces (Island Spar, Chihuahua, Mexico) through in-situ nanoscale observation using in situ atomic force microscopy (AFM, Multimode, Bruker) in flow-through experiments. Changes in calcium oxalate morphologies and precipitated phases were observed, as well as the inhibitory effect of citrate on calcium oxalate precipitation, which also lead to stabilization an the amorphous calcium oxalate phase. [1] K.D. Demadis, M. Öner, Inhibitory effects of "green"additives on the crystal growth of sparingly soluble salts, in: J.T. Pearlman (Ed.), Green Chemistry Research Trends, Nova Science Publishers Inc., New York, 2009, pp. 265-287. [2] M. Masár, M. Zuborová, D. Kaniansky, B. Stanislawski, Determination of oxalate in beer by zone electrophoresis on a chip with conductivity detection, J. Sep. Sci. 26 (2003) 647-652. [3] Chutipongtanate S, Chaiyarit S, Thongboonkerd V. Citrate, not phosphate, can dissolve calcium oxalate monohydrate crystals and detach these crystals from renal tubular cells. Eur J Pharmacol 2012;689:219-25. [4] Weaver ML, Qiu SR, Hoyer JR, Casey WH, Nancollas GH, De Yoreo JJ

Formation of apatitic calcium phosphates in a Na-K-phosphate solution of pH 7.4.

PubMed

Tas, A C; Aldinger, F

2005-02-01

Poorly crystalline, apatitic calcium phosphate powders have been synthesized by slowly adding a Na- and K-containing reference phosphate solution with a pH value of 7.4 to an aqueous calcium nitrate solution at 37 degrees C. Nano-particulated apatitic powders obtained were shown to contain small amounts of Na and K, which render them more similar in chemical composition to that of the bone mineral. Precipitated and dried powders were found to exhibit self-hardening cement properties when kneaded in a mortar with a sodium citrate- and sodium phosphate-containing starter solution. The same phosphate solution used in powder synthesis was found to be able to partially convert natural, white and translucent marble pieces of calcite (CaCO3) into calcium-deficient hydroxyapatite upon aging the samples in that solution for 3 days at 60 degrees C. Sample characterization was performed by using scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, inductively-coupled plasma atomic emission spectroscopy, and simultaneous thermogravimetry and differential thermal analysis.

Citrate salts for preventing and treating calcium containing kidney stones in adults.

PubMed

Phillips, Rebecca; Hanchanale, Vishwanath S; Myatt, Andy; Somani, Bhaskar; Nabi, Ghulam; Biyani, C Shekhar

2015-10-06

Kidney stones affect people worldwide and have a high rate of recurrence even with treatment. Recurrences are particularly prevalent in people with low urinary citrate levels. These people have a higher incidence of calcium phosphate and calcium oxalate stones. Oral citrate therapy increases the urinary citrate levels, which in turn binds with calcium and inhibits the crystallisation thus reduces stone formation. Despite the widespread use of oral citrate therapy for prevention and treatment of calcium oxalate stones, the evidence to support its clinical efficacy remains uncertain. The objective of this review was to determine the efficacy and adverse events associated with citrate salts for the treatment and prevention of calcium containing kidney stones. We searched the Cochrane Kidney and Transplant Specialised Register to 29 July 2015 through contact with the Trials' Search Co-ordinator using search terms relevant to this review. We included randomised controlled trials (RCTs) that assessed the efficacy and adverse events associated with citrate salts for the treatment and prevention of calcium containing kidney stones in adults treated for a minimum of six months. Two authors assessed studies for inclusion in this review. Data were extracted according to predetermined criteria. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes. We included seven studies that included a total of 477 participants, most of whom had oxalate stones. Of these, three studies (247 participants) compared potassium citrate with placebo or no intervention; three (166 participants) compared potassium-sodium citrate with no intervention; and one (64 participants) compared potassium-magnesium citrate with placebo. Overall, quality of the reporting of the included studies was considered moderate to

Citrate and renal calculi: an update

NASA Technical Reports Server (NTRS)

Pak, C. Y.

1994-01-01

Citrate is an inhibitor of the crystallization of stone-forming calcium salts. Hypocitraturia, frequently encountered in patients with nephrolithiasis, is therefore an important risk factor for stone formation. Potassium citrate provides physiological and physicochemical correction and inhibits new stone formation, not only in hypocitraturic calcium nephrolithiasis but also in uric acid nephrolithiasis. Inhibition of stone recurrence has now been validated by a randomized trial. Ongoing research has disclosed additional causes of hypocitraturia (sodium excess, low intestinal alkali absorption, but not primary citrate malabsorption). Moreover, new insights on potassium citrate action have been shown, notably that some of absorbed citrate escapes oxidation and contributes to the citraturic response, that ingestion with a meal does not sacrifice physiological or physicochemical action, that orange juice mimics but does not completely duplicate its actions, that potassium citrate may have a beneficial bone-sparing effect, that it may reduce stone fragments following ESWL, and that danger of aluminum toxicity is not great in subjects with functioning kidneys. Finally, the research on potassium citrate has led to two promising products, calcium citrate as an optimum calcium supplement and potassium-magnesium citrate which may be superior to potassium citrate in the management of stone disease.

Performance of a hydrogen uranyl phosphate-carbon double-layer solid capacitor

NASA Astrophysics Data System (ADS)

Pham-Thi, M.; Adet, Ph.; Velasco, G.; Colomban, Ph.

1986-05-01

A mixture of commercially available carbon black (C) powders and hydrogen uranyl phosphate (HUP) precipitate can be used as the electrode material for miniaturized double-layer capacitors. A solid cell of C-HUP/HUP/C-HUP has a capacitance of 1 F which, given the device area and thickness of 0.8 sq cm and 0.2 cm respectively, corresponds to an energy density of more than 5 J/cu cm. The charge x voltage factor is higher than 5 x 10 to the -6th s and the working voltage is over 1.6 V. The leakage current is lower than 3 microamps at room temperature. The electrolyte can be operated up to about 120 C if the device is hermetically sealed.

Mutation of the oxaloacetate decarboxylase gene of Lactococcus lactis subsp. lactis impairs the growth during citrate metabolism.

PubMed

Augagneur, Y; Garmyn, D; Guzzo, J

2008-01-01

Citrate metabolism generates metabolic energy through the generation of a membrane potential and a pH gradient. The purpose of this work was to study the influence of oxaloacetate decarboxylase in citrate metabolism and intracellular pH maintenance in relation to acidic conditions. A Lactococcus lactis oxaloacetate decarboxylase mutant [ILCitM (pFL3)] was constructed by double homologous recombination. During culture with citrate, and whatever the initial pH, the growth rate of the mutant was lower. In addition, the production of diacetyl and acetoin was altered in the mutant strain. However, our results indicated no relationship with a change in the maintenance of intracellular pH. Experiments performed on resting cells clearly showed that oxaloacetate accumulated temporarily in the supernatant of the mutant. This accumulation could be involved in the perturbations observed during citrate metabolism, as the addition of oxaloacetate in M17 medium inhibited the growth of L. lactis. The mutation of oxaloacetate decarboxylase perturbed citrate metabolism and reduced the benefits of its utilization during growth under acidic conditions. This study allows a better understanding of citrate metabolism and the role of oxaloacetate decarboxylase in the tolerance of lactic acid bacteria to acidic conditions.

Sildenafil citrate and uteroplacental perfusion in fetal growth restriction

PubMed Central

Dastjerdi, Marzieh Vahid; Hosseini, Sayedehafagh; Bayani, Leila

2012-01-01

Background: To determine whether the phosphodiesterase type 5 inhibitor, Sildenafil citrate, affects uteroplacental perfusion. Materials and Methods: Based on a randomized double-blinded and placebo-controlled trial, forty one pregnant women with documented intrauterine growth retardation at 24-37 weeks of gestation were evaluated for the effect of a single dose of Sildenafil citrate on uteroplacental circulation as determined by Doppler ultrasound study of the umbilical and middle cerebral arteries. Statistical analysis included χ2-test to compare proportions, and independent-samples t-test and paired student's t-test to compare continuous variables. Results: Sildenafil group fetuses demonstrated a significant decrease in systolic/diastolic ratios (0.60 [SD 0.40] [95% Cl 0.37-0.84], P=0.000), and pulsatility index (0.12 [SD 0.15] [95% Cl 0.02-0.22], P=0.019) for the umbilical artery and a significant increase in middle cerebral artery pulsatility index (MCA PI) (0.51 [SD 0.60] [95% Cl 0.16-0.85], P=0.008). Conclusion: Doppler velocimetry index values reflect decreased placental bed vascular resistance after Sildenafil. Sildenafil citrate can improve fetoplacental perfusion in pregnancies complicated by intrauterine growth restriction. It could be a potential therapeutic strategy to improve uteroplacental blood flow in pregnancies with fetal growth restriction (FGR). PMID:23798922

Alverine citrate plus simethicone reduces cecal intubation time in colonoscopy - a randomized study.

PubMed

Altintaş, Engin; Uçbilek, Enver; Sezgin, Orhan; Sayici, Yasin

2008-09-01

Successful colonoscopy depends on the insertion of the instrument to the cecum, a detailed examination, and minimal discomfort to the patient during the procedure. The aim of this study was to determine the effects of alverine citrate plus simethicone on the cecal intubation time, colonic spasm and bowel cleanliness. A prospective, randomized, controlled trial in a consecutive series of patients was conducted to compare alverine citrate as an antispasmodic agent for relaxation of spasm with elective colonoscopy. The drug used consisted of 60 mg alverine citrate plus 300 mg simethicone. Sodium phosphate soda and enema were recommended for bowel cleansing. During colonoscopy, spasticity, difficulty of the procedure, pain, and cleanliness of the colon were scored between 0-4. The time required to reach the cecum was recorded as minutes. Of 165 total patients, 83 and 82 patients were randomized as the drug group (mean age: 51.85+/-13.47 years) and control group (mean age: 51.68+/-16.28 years), respectively. There was a statistically significant difference between the groups in the mean time to reach the cecum in favor of the drug group (7.48+/-3.45 minutes vs. 6.20+/-3.24 minutes; p=0.02). The time to reach the cecum prolonged with an increase in pain score and difficulty score (p=0.0001 and p=0.001, respectively). Alverine citrate plus simethicone reduced the intubation time significantly by 19%, from 7.48 minutes to 6.20 minutes.

Effects of supplementation on food intake, body weight and hepatic metabolites in the citrin/mitochondrial glycerol-3-phosphate dehydrogenase double-knockout mouse model of human citrin deficiency.

PubMed

Saheki, Takeyori; Inoue, Kanako; Ono, Hiromi; Katsura, Natsumi; Yokogawa, Mana; Yoshidumi, Yukari; Furuie, Sumie; Kuroda, Eishi; Ushikai, Miharu; Asakawa, Akihiro; Inui, Akio; Eto, Kazuhiro; Kadowaki, Takashi; Sinasac, David S; Yamamura, Ken-Ichi; Kobayashi, Keiko

2012-11-01

The C57BL/6:Slc23a13(-/-);Gpd2(-/-) double-knockout (a.k.a., citrin/mitochondrial glycerol 3-phosphate dehydrogenase double knockout or Ctrn/mGPD-KO) mouse displays phenotypic attributes of both neonatal intrahepatic cholestasis (NICCD) and adult-onset type II citrullinemia (CTLN2), making it a suitable model of human citrin deficiency. In the present study, we show that when mature Ctrn/mGPD-KO mice are switched from a standard chow diet (CE-2) to a purified maintenance diet (AIN-93M), this resulted in a significant loss of body weight as a result of reduced food intake compared to littermate mGPD-KO mice. However, supplementation of the purified maintenance diet with additional protein (from 14% to 22%; and concomitant reduction or corn starch), or with specific supplementation with alanine, sodium glutamate, sodium pyruvate or medium-chain triglycerides (MCT), led to increased food intake and body weight gain near or back to that on chow diet. No such effect was observed when supplementing the diet with other sources of fat that contain long-chain fatty acids. Furthermore, when these supplements were added to a sucrose solution administered enterally to the mice, which has been shown previously to lead to elevated blood ammonia as well as altered hepatic metabolite levels in Ctrn/mGPP-KO mice, this led to metabolic correction. The elevated hepatic glycerol 3-phosphate and citrulline levels after sucrose administration were suppressed by the administration of sodium pyruvate, alanine, sodium glutamate and MCT, although the effect of MCT was relatively small. Low hepatic citrate and increased lysine levels were only found to be corrected by sodium pyruvate, while alanine and sodium glutamate both corrected hepatic glutamate and aspartate levels. Overall, these results suggest that dietary factors including increased protein content, supplementation of specific amino acids like alanine and sodium glutamate, as well as sodium pyruvate and MCT all show beneficial

Crystal Structure of Heart 6-Phosphofructo-2-Kinase/Fructose-2,6-Bisphosphatase (PFKFB2) and the Inhibitory Influence of Citrate on Substrate Binding

PubMed Central

Crochet, Robert B.; Kim, Jeong-Do; Lee, Herie; Yim, Young-Sun; Kim, Song-Gun; Neau, David; Lee, Yong-Hwan

2016-01-01

The heart-specific isoform of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB2) is an important regulator of glycolytic flux in cardiac cells. Here, we present the crystal structures of two PFKFB2 orthologues, human and bovine, at resolutions of 2.0 and 1.8Å, respectively. Citrate, a TCA cycle intermediate and well-known inhibitor of PFKFB2, co-crystallized in the 2-kinase domains of both orthologues, occupying the fructose-6-phosphate binding-site and extending into the γ-phosphate binding pocket of ATP. This steric and electrostatic occlusion of the γ-phosphate site by citrate proved highly consequential to the binding of co-complexed ATP analogues. The bovine structure, which co-crystallized with ADP, closely resembled the overall structure of other PFKFB isoforms, with ADP mimicking the catalytic binding mode of ATP. The human structure, on the other hand, co-complexed with AMPPNP, which, unlike ADP, contains a γ-phosphate. The presence of this γ-phosphate made adoption of the catalytic ATP binding mode impossible for AMPPNP, forcing the analogue to bind atypically with concomitant conformational changes to the ATP binding-pocket. Inhibition kinetics were used to validate the structural observations, confirming citrate’s inhibition mechanism as competitive for F6P and noncompetitive for ATP. Together, these structural and kinetic data establish a molecular basis for citrate’s negative feed-back loop of the glycolytic pathway via PFKFB2. PMID:27802586

Cofortification of ferric pyrophosphate and citric acid/trisodium citrate into extruded rice grains doubles iron bioavailability through in situ generation of soluble ferric pyrophosphate citrate complexes.

PubMed

Hackl, Laura; Cercamondi, Colin I; Zeder, Christophe; Wild, Daniela; Adelmann, Horst; Zimmermann, Michael B; Moretti, Diego

2016-05-01

Iron fortification of rice is a promising strategy for improving iron nutrition. However, it is technically challenging because rice is consumed as intact grains, and ferric pyrophosphate (FePP), which is usually used for rice fortification, has low bioavailability. We investigated whether the addition of a citric acid/trisodium citrate (CA/TSC) mixture before extrusion increases iron absorption in humans from FePP-fortified extruded rice grains. We conducted an iron absorption study in iron-sufficient young women (n = 20), in which each participant consumed 4 different meals (4 mg Fe/meal): 1) extruded FePP-fortified rice (No CA/TSC); 2) extruded FePP-fortified rice with CA/TSC added before extrusion (CA/TSC extruded); 3) extruded FePP-fortified rice with CA/TSC solution added after cooking and before consumption (CA/TSC solution); and 4) nonextruded rice fortified with a FeSO4 solution added after cooking and before consumption (reference). Iron absorption was calculated from erythrocyte incorporation of stable iron isotopes 14 d after administration. In in vitro experiments, we assessed the soluble and dialyzable iron from rice meals in which CA/TSC was added at different preparation stages and from meals with different iron:CA:TSC ratios. Fractional iron absorption was significantly higher from CA/TSC-extruded meals (3.2%) than from No CA/TSC (1.7%) and CA/TSC solution (1.7%; all P < 0.05) and was not different from the FeSO4 reference meal (3.4%). In vitro solubility and dialyzability were higher in CA/TSC-extruded rice than in rice with No CA/TSC and CA/TSC solution, and solubility increased with higher amounts of added CA and TSC in extruded rice. Iron bioavailability nearly doubled when CA/TSC was extruded with FePP into fortified rice, resulting in iron bioavailability comparable to that of FeSO4 We attribute this effect to an in situ generation of soluble FePP citrate moieties during extrusion and/or cooking because of the close physical proximity of Fe

Remote loading of doxorubicin into liposomes driven by a transmembrane phosphate gradient.

PubMed

Fritze, Andreas; Hens, Felicitas; Kimpfler, Andrea; Schubert, Rolf; Peschka-Süss, Regine

2006-10-01

This study examines a new method for the remote loading of doxorubicin into liposomes. It was shown that doxorubicin can be loaded to a level of up to 98% into large unilamellar vesicles composed of egg phosphatidylcholine/cholesterol (7/3 mol/mol) with a transmembrane phosphate gradient. The different encapsulation efficiencies which were achieved with ammonium salts (citrate 100%, phosphate 98%, sulfate 95%, acetate 77%) were significantly higher as compared to the loading via sodium salts (citrate 54%, phosphate 52%, sulfate 44%, acetate 16%). Various factors, including pH-value, buffer capacity, solubility of doxorubicin in different salt solutions and base counter-flow, which likely has an influence on drug accumulation in the intraliposomal interior are taken into account. In contrast to other methods, the newly developed remote loading method exhibits a pH-dependent drug release property which may be effective in tumor tissues. At physiological pH-value doxorubicin is retained in the liposomes, whereas drug release is achieved by lowering the pH to 5.5 (approximately 25% release at 25 degrees C or 30% at 37 degrees C within two h). The DXR release of liposomes which were loaded via a sulfate gradient showed a maximum of 3% at pH 5.5.

Physicochemical action of potassium-magnesium citrate in nephrolithiasis

NASA Technical Reports Server (NTRS)

Pak, C. Y.; Koenig, K.; Khan, R.; Haynes, S.; Padalino, P.

1992-01-01

Effect of potassium-magnesium citrate on urinary biochemistry and crystallization of stone-forming salts was compared with that of potassium citrate at same dose of potassium in five normal subjects and five patients with calcium nephrolithiasis. Compared to the placebo phase, urinary pH rose significantly from 6.06 +/- 0.27 to 6.48 +/- 0.36 (mean +/- SD, p less than 0.0167) during treatment with potassium citrate (50 mEq/day for 7 days) and to 6.68 +/- 0.31 during therapy with potassium-magnesium citrate (containing 49 mEq K, 24.5 mEq Mg, and 73.5 mEq citrate per day). Urinary pH was significantly higher during potassium-magnesium citrate than during potassium citrate therapy. Thus, the amount of undissociated uric acid declined from 118 +/- 61 mg/day during the placebo phase to 68 +/- 54 mg/day during potassium citrate treatment and, more prominently, to 41 +/- 46 mg/day during potassium-magnesium citrate therapy. Urinary magnesium rose significantly from 102 +/- 25 to 146 +/- 37 mg/day during potassium-magnesium citrate therapy but not during potassium citrate therapy. Urinary citrate rose more prominently during potassium-magnesium citrate therapy (to 1027 +/- 478 mg/day from 638 +/- 252 mg/day) than during potassium citrate treatment (to 932 +/- 297 mg/day). Consequently, urinary saturation (activity product) of calcium oxalate declined significantly (from 1.49 x 10(-8) to 1.03 x 10(-8) M2) during potassium-magnesium citrate therapy and marginally (to 1.14 x 10(-8) M2) during potassium citrate therapy.(ABSTRACT TRUNCATED AT 250 WORDS).

Optimization of the Use of Selected Non-Phosphate Water Retention Additives in Minced Beef Using Response Surface Methodology

NASA Astrophysics Data System (ADS)

Shang, Xiaolan; Qiao, Jie; Liu, Yujie

2017-12-01

This study looked to determine what the optimum cooking loss for minced beef was when three different non-phosphate water retention additives (L-Arginine, sodium carbonate, and sodium citrate) were combined; the optimum value was determined using a Box-Behnken response surface design method. The optimum value was found to be 8.26%, and it was obtained when 0.29% L-Arginine, 0.45% sodium carbonate, and 0.24% sodium citrate were added to the beef.

Phosphate Removal by Anion Binding on Functionalized Nanoporous Sorbents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chouyyok, Wilaiwan; Wiacek, Robert J.; Pattamakomsan, Kanda

2010-03-26

Phosphate was captured from aqueous solutions by cationic metal-EDA complexes anchored inside mesoporous silica MCM-41 supports (Cu(II)-EDA-SAMMS and Fe(III)-EDA-SAMMS). Fe-EDA-SAMMS was more effective at capturing phosphate than the Cu-EDA-SAMMS and was further studied for matrix effects (e.g., pH, ionic strength, and competing anions) and sorption performance (e.g., capacity and rate). The adsorption of phosphate was highly pH dependent; it increased with increasing pH from 1.0 to 6.5, and decreased above pH 6.5. The adsorption was affected by high ionic strength (0.1 M of NaCl). In the presence of 1000-fold molar excess of chloride and nitrate anions, phosphate removal by Fe-EDA-SAMMSmore » was not affected. Slight, moderate and large impacts were seen with bicarbonate, sulfate and citrate anions, respectively. The phosphate adsorption data on Fe-EDA-SAMMS agreed well with the Langmuir model with the estimated maximum capacity of 43.3 mg/g. The material displayed rapid sorption rate (99% of phosphate removal within 1 min) and lowering the phosphate content to ~ 10 µg/L of phosphorus, which is lower than the EPA’s established freshwater contaminant level for phosphorous (20 µg/L).« less

Metformin versus chromium picolinate in clomiphene citrate-resistant patients with PCOs: A double-blind randomized clinical trial.

PubMed

Amooee, Sedigheh; Parsanezhad, Mohammad Ebrahim; Ravanbod Shirazi, Maryam; Alborzi, Saeed; Samsami, Alamtaj

2013-08-01

Chromium picolinate could be effective in clomiphen citrate resistant PCOS patients. To compare the effects of chromium picolinate vs. metformin in clomiphen citrate resistant PCOS patients. The present randomized clinical trial was performed on 92 women with clomiphen citrate-resistant PCOS at the clinics which were affiliated to Shiraz University of Medical Sciences, Shiraz, Iran. The subjects were randomly assigned to two groups receiving either chromium picolinate (200µg daily) or metformin (1500mg daily) for 3 months. Anthropometric and hormonal profile were measured and compared both before and after the treatment. Ovulation and pregnancy rate was measured in the two study groups, as well. Chromium picolinate significantly decreased fasting blood sugar (FBS) after 3 months of treatment (p=0.042). In the same way, the serum levels of fasting insulin had significantly decreased leading to an increase in insulin sensitivity as measured by QUICKI index (p=0.014). In comparison to the patients who received chromium picolinate, those who received metformin had significantly lower levels of testosterone (p=0.001) and free testosterone (p=0.001) after 3 months of treatment. Nevertheless, no significant difference was found between the two study groups regarding ovulation (p=0.417) and pregnancy rates (p=0.500). Chromium picolinate decreased FBS and insulin levels and, thus, increased insulin sensitivity in clomiphene citrate-resistance PCOS women. These effects were comparable with metformin; however, metformin treatment was associated with decreased hyperandrogenism. Overall, chromium picolinate was better tolerated compared to metformin; nonetheless, the two study groups were not significantly different regarding ovulation and pregnancy rates. Registration ID in IRCT: IRCT201203139281N1.

21 CFR 582.6195 - Calcium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Calcium citrate. 582.6195 Section 582.6195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.6195 - Calcium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium citrate. 582.6195 Section 582.6195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.6625 - Potassium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.1625 - Potassium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This...

21 CFR 582.1625 - Potassium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This...

21 CFR 582.1625 - Potassium citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This...

21 CFR 582.1625 - Potassium citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This...

21 CFR 582.6625 - Potassium citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.6625 - Potassium citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.6625 - Potassium citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.1625 - Potassium citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This...

21 CFR 582.6625 - Potassium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.6195 - Calcium citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Calcium citrate. 582.6195 Section 582.6195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.6195 - Calcium citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Calcium citrate. 582.6195 Section 582.6195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.6195 - Calcium citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Calcium citrate. 582.6195 Section 582.6195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.1195 - Calcium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Calcium citrate. 582.1195 Section 582.1195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is...

21 CFR 582.6751 - Sodium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium citrate. 582.6751 Section 582.6751 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 2 § 582.6751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is generally recognized as...

21 CFR 582.6751 - Sodium citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sodium citrate. 582.6751 Section 582.6751 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 2 § 582.6751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is generally recognized as...

21 CFR 582.1751 - Sodium citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sodium citrate. 582.1751 Section 582.1751 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.6751 - Sodium citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium citrate. 582.6751 Section 582.6751 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 2 § 582.6751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is generally recognized as...

21 CFR 582.1751 - Sodium citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium citrate. 582.1751 Section 582.1751 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.1751 - Sodium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium citrate. 582.1751 Section 582.1751 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.6751 - Sodium citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium citrate. 582.6751 Section 582.6751 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 2 § 582.6751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is generally recognized as...

21 CFR 582.6751 - Sodium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium citrate. 582.6751 Section 582.6751 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 2 § 582.6751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is generally recognized as...

21 CFR 582.1751 - Sodium citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium citrate. 582.1751 Section 582.1751 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.1751 - Sodium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium citrate. 582.1751 Section 582.1751 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is generally...

Sequestration of Sr-90 Subsurface Contamination in the Hanford 100-N Area by Surface Infiltration of a Ca-Citrate-Phosphate Solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szecsody, James E.; Rockhold, Mark L.; Oostrom, Martinus

The objective of this project is to develop a method to emplace apatite precipitate in the 100N vadose zone, which results in sorption and ultimately incorporation of Sr-90 into the apatite structure. The Ca-citrate-PO4 solution can be infiltrated into unsaturated sediments to result in apatite precipitate to provide effective treatment of Sr-90 contamination. Microbial redistribution during solution infiltration and a high rate of citrate biodegradation for river water microbes (water used for solution infiltration) results in a relatively even spatial distribution of the citrate biodegradation rate and ultimately apatite precipitate in the sediment. Manipulation of the Ca-citrate-PO4 solution infiltration strategymore » can be used to result in apatite precipitate in the lower half of the vadose zone (where most of the Sr-90 is located) and within low-K layers (which are hypothesized to have higher Sr-90 concentrations). The most effective infiltration strategy to precipitate apatite at depth (and with sufficient lateral spread) was to infiltrate a high concentration solution (6 mM Ca, 15 mM citrate, 60 mM PO4) at a rapid rate (near ponded conditions), followed by rapid, then slow water infiltration. Repeated infiltration events, with sufficient time between events to allow water drainage in the sediment profile can be used to buildup the mass of apatite precipitate at greater depth. Low-K heterogeneities were effectively treated, as the higher residual water content maintained in these zones resulted in higher apatite precipitate concentration. High-K zones did not receive sufficient treatment by infiltration, although an alternative strategy of air/surfactant (foam) was demonstrated effective for targeting high-K zones. The flow rate manipulation used in this study to treat specific depths and heterogeneities are not as easy to implement at field scale due to the lack of characterization of heterogeneities and difficulty tracking the wetting front over a

21 CFR 184.1625 - Potassium citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium citrate. 184.1625 Section 184.1625 Food... GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS Reg. No. 006100-0905-096) is the potassium salt of citric acid. It is prepared by neutralizing citric acid with potassium...

Sildenafil citrate for erectile dysfunction in patients with multiple sclerosis.

PubMed

Xiao, Yousheng; Wang, Jin; Luo, Hongye

2012-04-18

effective in quality of life improvement, while the other trial did not find any significant difference between both groups. Both included trials were judged as high risk of attrition bias. Adverse events were also reported: the most common were headache, flushing, rhinitis, visual disturbances and dyspepsia. Two patients suffered serious adverse events: one with coronary artery disease requiring triple bypass surgery and one with a cerebrovascular accident. There is limited evidence to support sildenafil citrate as an effective treatment for ED in patients with MS. Future well designed randomised, double blinded, placebo-controlled trials with long-term duration are needed.

Interactive effects of redox intensity and phosphate availability on growth and nutrient relations of Cladium jamaicense (Cyperaceae)

USGS Publications Warehouse

Lissner, J.; Mendelssohn, I.A.; Lorenzen, B.; Brix, H.; McKee, K.L.; Miao, S.L.

2003-01-01

Expansion of Typha domingensis into areas previously dominated by Cladium jamaicense in the Florida Everglades has been linked to anthropogenic phosphorus (P) enrichment and increased hydroperiod. The principal stress factor for plants in flooded soils is biochemical reduction, the intensity of which is measured as redox potential (Eh). The objective of this study was to assess the growth response of C. jamaicense to Eh (-150, +150, and +600 mV) and P availability (10, 80, and 500 ??g P/L). Plants were grown hydroponically in a factorial experiment using titanium (Ti3+) citrate as an Eh buffer. Treatment effects on growth, biomass partitioning, and tissue nutrients were recorded. Growth approximately doubled in response to a 50-fold increase in P availability. Low redox significantly reduced growth and tissue P concentration. While plant P concentrations increased 20-fold between the 10 and 500 ??g P/L treatments, P concentrations were 50-100% higher at +600 mV than at -150 mV within each phosphate level. At high Eh, C. jamaicense appears well adapted to low nutrient environments because of its low P requirement and high retention of acquired E However, at low Eh the ability to acquire or conserve acquired P decreases and as a consequence, higher phosphate levels are required to sustain growth. Findings of this study indicate that young C. jamaicense exhibits low tolerance to strongly reducing conditions when phosphate is scarce.

Probing intermolecular interactions in a diethylcarbamazine citrate salt by fast MAS 1H solid-state NMR spectroscopy and GIPAW calculations.

PubMed

Venâncio, Tiago; Oliveira, Lyege Magalhaes; Ellena, Javier; Boechat, Nubia; Brown, Steven P

2017-10-01

Fast magic-angle spinning (MAS) NMR is used to probe intermolecular interactions in a diethylcarbamazine salt, that is widely used as a treatment against adult worms of Wuchereria bancrofti which cause a common disease in tropical countries named filariasis. Specifically, a dihydrogen citrate salt that has improved thermal stability and solubility as compared to the free form is studied. One-dimensional 1 H, 13 C and 15 N and two-dimensional 1 H- 13 C and 14 N- 1 H heteronuclear correlation NMR experiments under moderate and fast MAS together with GIPAW (CASTEP) calculations enable the assignment of the 1 H, 13 C and 14 N/ 15 N resonances. A two-dimensional 1 H- 1 H double-quantum (DQ) -single-quantum (SQ) MAS spectrum recorded with BaBa recoupling at 60kHz MAS identifies specific proton-proton proximities associated with citrate-citrate and citrate-diethylcarbamazine intermolecular interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

21 CFR 184.1195 - Calcium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Calcium citrate. 184.1195 Section 184.1195 Food... Specific Substances Affirmed as GRAS § 184.1195 Calcium citrate. (a) Calcium citrate (Ca3(C6H5O7)2·4H2O, CAS Reg. No. 813-0994-095) is the calcium salt of citric acid. It is prepared by neutralizing citric...

21 CFR 184.1625 - Potassium citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium citrate. 184.1625 Section 184.1625 Food... Specific Substances Affirmed as GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS Reg. No. 006100-0905-096) is the potassium salt of citric acid. It is prepared by neutralizing citric...

21 CFR 184.1625 - Potassium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium citrate. 184.1625 Section 184.1625 Food... Specific Substances Affirmed as GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS Reg. No. 006100-0905-096) is the potassium salt of citric acid. It is prepared by neutralizing citric...

21 CFR 184.1625 - Potassium citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium citrate. 184.1625 Section 184.1625 Food... Specific Substances Affirmed as GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS Reg. No. 006100-0905-096) is the potassium salt of citric acid. It is prepared by neutralizing citric...

21 CFR 184.1751 - Sodium citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium citrate. 184.1751 Section 184.1751 Food and....1751 Sodium citrate. (a) Sodium citrate (C6H5Na3O7·2H2O, CAS Reg. No. 68-0904-092) is the sodium salt of citric acid. It is prepared by neutralizing citric acid with sodium hydroxide or sodium carbonate...

21 CFR 184.1625 - Potassium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium citrate. 184.1625 Section 184.1625 Food... Specific Substances Affirmed as GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS Reg. No. 006100-0905-096) is the potassium salt of citric acid. It is prepared by neutralizing citric...

21 CFR 184.1195 - Calcium citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Calcium citrate. 184.1195 Section 184.1195 Food... GRAS § 184.1195 Calcium citrate. (a) Calcium citrate (Ca3(C6H5O7)2·4H2O, CAS Reg. No. 813-0994-095) is the calcium salt of citric acid. It is prepared by neutralizing citric acid with calcium hydroxide or...

Sildenafil citrate for the management of antidepressant-associated erectile dysfunction.

PubMed

Nurnberg, H George; Hensley, Paula L

2003-01-01

Sexual side effects of serotonin reuptake inhibitors, such as antidepressant-associated erectile dysfunction, are common and negatively impact treatment compliance. Current management approaches have important limitations, and most lack clear and meaningful efficacy in double-blind, placebo-controlled trials. A MEDLINE search (English language, 1966-2003) was performed using the terms antidepressive agents, erectile dysfunction, and sildenafil. Emphasis was placed on studies that used specific sexual function measurements and were placebo controlled. Sildenafil citrate, a selective and competitive inhibitor of phosphodiesterase type 5, enhances the cyclic guanosine monophosphate-mediated relaxation of cavernosal smooth muscles in response to sexual stimulation, permitting vascular engorgement and penile erection. The efficacy and tolerability of sildenafil in the treatment of antidepressant-associated erectile dysfunction have been confirmed in double-blind, placebo-controlled trials.

Evaluation of ocular and general safety following repeated dosing of dexamethasone phosphate delivered by transscleral iontophoresis in rabbits.

PubMed

Patane, Michael A; Schubert, William; Sanford, Thomas; Gee, Raymond; Burgos, Melissa; Isom, William P; Ruiz-Perez, Begona

2013-10-01

To evaluate the toxicokinetics and tolerability (local ocular and general toxicity) of the anti-inflammatory agent, dexamethasone phosphate (a prodrug of dexamethasone) delivered to the eye in rabbits by transscleral iontophoresis. Female rabbits (n=6/group) received dexamethasone phosphate (40 mg/mL ophthalmic solution, EGP-437) transsclerally to the right eye (OD) using the Eyegate(®) II ocular iontophoresis delivery system once biweekly for 24 consecutive weeks at current doses of 10, 14, and 20 mA-min and current levels up to, and including -4 mA for 3.5-5 min. The study included 2 control groups (n=6/group): (1) a noniontophoresis control [an ocular applicator-loaded citrate buffer (placebo) without current] and (2) an iontophoresis control (a citrate buffer plus cathode iontophoresis at 20 mA-min, -4 mA for 5 min). Recoverability was evaluated 4 weeks following the last dose in 2 animals per group. The left eye (OS) was untreated and served as an internal control for each animal. Ocular and general safety of dexamethasone phosphate and dexamethasone were assessed. Other evaluations included toxicokinetics, ophthalmic examinations, intraocular pressure (IOP) measurements, electroretinographs, clinical observations, body weight, hematology and serum chemistry, gross necropsy, organ weight, and microscopic histopathology. The biweekly transscleral iontophoresis with either the citrate buffer or dexamethasone phosphate at cathodic doses up to, and including 20 mA-min and currents up to, and including -4 mA for 24 weeks was well-tolerated. Transient signs of conjunctival hyperemia and chemosis, mild corneal opacity, and fluorescein staining of the cornea were noted and attributed to expected ocular reactions to the temporary placement of the ocular applicator and application of iontophoresis. There were no dexamethasone phosphate-, dexamethasone-, or iontophoresis-related effects on IOP, electroretinography, or histopathology. Reductions in body weight gain

21 CFR 184.1195 - Calcium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium citrate. 184.1195 Section 184.1195 Food and... Substances Affirmed as GRAS § 184.1195 Calcium citrate. (a) Calcium citrate (Ca3(C6H5O7)2·4H2O, CAS Reg. No. 813-0994-095) is the calcium salt of citric acid. It is prepared by neutralizing citric acid with...

21 CFR 184.1751 - Sodium citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium citrate. 184.1751 Section 184.1751 Food and... Substances Affirmed as GRAS § 184.1751 Sodium citrate. (a) Sodium citrate (C6H5Na3O7·2H2O, CAS Reg. No. 68-0904-092) is the sodium salt of citric acid. It is prepared by neutralizing citric acid with sodium...

21 CFR 184.1751 - Sodium citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium citrate. 184.1751 Section 184.1751 Food and... Substances Affirmed as GRAS § 184.1751 Sodium citrate. (a) Sodium citrate (C6H5Na3O7·2H2O, CAS Reg. No. 68-0904-092) is the sodium salt of citric acid. It is prepared by neutralizing citric acid with sodium...

21 CFR 184.1751 - Sodium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium citrate. 184.1751 Section 184.1751 Food and... Substances Affirmed as GRAS § 184.1751 Sodium citrate. (a) Sodium citrate (C6H5Na3O7·2H2O, CAS Reg. No. 68-0904-092) is the sodium salt of citric acid. It is prepared by neutralizing citric acid with sodium...

21 CFR 184.1751 - Sodium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium citrate. 184.1751 Section 184.1751 Food and... Substances Affirmed as GRAS § 184.1751 Sodium citrate. (a) Sodium citrate (C6H5Na3O7·2H2O, CAS Reg. No. 68-0904-092) is the sodium salt of citric acid. It is prepared by neutralizing citric acid with sodium...

Combined coenzyme Q10 and clomiphene citrate for ovulation induction in clomiphene-citrate-resistant polycystic ovary syndrome.

PubMed

El Refaeey, Abdelaziz; Selem, Amal; Badawy, Ahmed

2014-07-01

This prospective randomized controlled trial evaluated the effect of combined oral coenzyme Q10 (CoQ10) and clomiphene citrate for ovulation induction in clomiphene-citrate-resistant polycystic ovary syndrome (PCOS). A total of 101 infertile women with PCOS resistant to clomiphene citrate were randomized either to combined CoQ10 and clomiphene citrate (51 patients, 82 cycles) or to clomiphene citrate alone (50 patients, 71 cycles). The outcome measures were number of follicles, serum oestradiol, serum progesterone, endometrial thickness and ovulation, clinical pregnancy and miscarriage rates. Numbers of follicles >14 mm and ≥18 mm were significantly higher in the CoQ10 group. Endometrial thickness on the day of human chorionic gonadotrophin was significantly greater in the CoQ10 group (8.82 ± 0.27 mm versus 7.03 ± 0.74 mm). Ovulation occurred in 54/82 cycles (65.9%) in the CoQ10 group and 11/71 cycles (15.5%) in the control group. Clinical pregnancy rate was significantly higher in the CoQ10 group (19/51, 37.3%) versus the control group (3/50, 6.0%). Combination of CoQ10 and clomiphene citrate in the treatment of clomiphene-citrate-resistant PCOS patients improves ovulation and clinical pregnancy rates. It is an effective and safe option and can be considered before gonadotrophin therapy or laparoscopic ovarian drilling. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Incompatibility of Contrast Medium and Trisodium Citrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delcour, Christian, E-mail: christian.delcour@chu-charleroi.be; Bruninx, Guy

2013-02-15

To test the compatibility of trisodium citrate, a catheter lock solution, with iodinated contrast medium. Iohexol, iobitridol, iodixanol, ioxaglate, ioxithalamate, iomeprol, and iopromide were tested. In all tests, 2 ml of contrast medium were mixed with 2 ml of trisodium citrate solution. Iodixanol and ioxaglate provoked a highly viscous gluelike precipitation when mixed with trisodium citrate. A brief transient precipitate was observed with iohexol, iomeprol, and ioxithalamate. Permanent precipitation occurred with iobitridol and iopromide. One must be aware of the potential for precipitation when contrast medium is mixed with trisodium citrate solution. Before trisodium citrate solution is injected, the cathetermore » should be thoroughly flushed with saline if a contrast medium has previously been injected through it.« less

Aroma compounds generation in citrate metabolism of Enterococcus faecium: Genetic characterization of type I citrate gene cluster.

PubMed

Martino, Gabriela P; Quintana, Ingrid M; Espariz, Martín; Blancato, Victor S; Magni, Christian

2016-02-02

Enterococcus is one of the most controversial genera belonging to Lactic Acid Bacteria. Research involving this microorganism reflects its dual behavior as regards its safety. Although it has also been associated to nosocomial infections, natural occurrence of Enterococcus faecium in food contributes to the final quality of cheese. This bacterium is capable of fermenting citrate, which is metabolized to pyruvate and finally derives in the production of the aroma compounds diacetyl, acetoin and 2,3 butanediol. Citrate metabolism was studied in E. faecium but no data about genes related to these pathways have been described. A bioinformatic approach allowed us to differentiate cit(-) (no citrate metabolism genes) from cit(+) strains in E. faecium. Furthermore, we could classify them according to genes encoding for the transcriptional regulator, the oxaloacetate decarboxylase and the citrate transporter. Thus we defined type I organization having CitI regulator (DeoR family), CitM cytoplasmic soluble oxaloacetate decarboxylase (Malic Enzyme family) and CitP citrate transporter (2-hydroxy-carboxylate transporter family) and type II organization with CitO regulator (GntR family), OAD membrane oxaloacetate decarboxylase complex (Na(+)-transport decarboxylase enzyme family) and CitH citrate transporter (CitMHS family). We isolated and identified 17 E. faecium strains from regional cheeses. PCR analyses allowed us to classify them as cit(-) or cit(+). Within the latter classification we could differentiate type I but no type II organization. Remarkably, we came upon E. faecium GM75 strain which carries the insertion sequence IS256, involved in adaptative and evolution processes of bacteria related to Staphylococcus and Enterococcus genera. In this work we describe the differential behavior in citrate transport, metabolism and aroma generation of three strains and we present results that link citrate metabolism and genetic organizations in E. faecium for the first time

Correction of metabolic acidosis with potassium citrate in renal transplant patients and its effect on bone quality.

PubMed

Starke, Astrid; Corsenca, Alf; Kohler, Thomas; Knubben, Johannes; Kraenzlin, Marius; Uebelhart, Daniel; Wüthrich, Rudolf P; von Rechenberg, Brigitte; Müller, Ralph; Ambühl, Patrice M

2012-09-01

Acidosis and transplantation are associated with increased risk of bone disturbances. This study aimed to assess bone morphology and metabolism in acidotic patients with a renal graft, and to ameliorate bone characteristics by restoration of acid/base homeostasis with potassium citrate. This was a 12-month controlled, randomized, interventional trial that included 30 renal transplant patients with metabolic acidosis (S-[HCO(3)(-)] <24 mmol/L) undergoing treatment with either potassium citrate to maintain S-[HCO(3)(-)] >24 mmol/L, or potassium chloride (control group). Iliac crest bone biopsies and dual-energy X-ray absorptiometry were performed at baseline and after 12 months of treatment. Bone biopsies were analyzed by in vitro micro-computed tomography and histomorphometry, including tetracycline double labeling. Serum biomarkers of bone turnover were measured at baseline and study end. Twenty-three healthy participants with normal kidney function comprised the reference group. Administration of potassium citrate resulted in persisting normalization of S-[HCO(3)(-)] versus potassium chloride. At 12 months, bone surface, connectivity density, cortical thickness, and cortical porosity were better preserved with potassium citrate than with potassium chloride, respectively. Serological biomarkers and bone tetracycline labeling indicate higher bone turnover with potassium citrate versus potassium chloride. In contrast, no relevant changes in bone mineral density were detected by dual-energy X-ray absorptiometry. Treatment with potassium citrate in renal transplant patients is efficient and well tolerated for correction of metabolic acidosis and may be associated with improvement in bone quality. This study is limited by the heterogeneity of the investigated population with regard to age, sex, and transplant vintage.

21 CFR 582.5449 - Manganese citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5449 Manganese citrate. (a) Product. Manganese citrate. (b) Conditions of use. This...

21 CFR 582.5449 - Manganese citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5449 Manganese citrate. (a) Product. Manganese citrate. (b) Conditions of use. This...

21 CFR 582.5449 - Manganese citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5449 Manganese citrate. (a) Product. Manganese citrate. (b) Conditions of use. This...

21 CFR 582.5449 - Manganese citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5449 Manganese citrate. (a) Product. Manganese citrate. (b) Conditions of use. This...

21 CFR 582.5449 - Manganese citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5449 Manganese citrate. (a) Product. Manganese citrate. (b) Conditions of use. This...

Inducible transport of citrate in Lactobacillus rhamnosus ATCC 7469.

PubMed

de Figueroa, R M; Benito de Cárdenas, I L; Sesma, F; Alvarez, F; de Ruiz Holgado, A P; Oliver, G

1996-10-01

Lactobacillus rhamnosus ATCC 7469 exhibited diauxie when grown in a medium containing both glucose and citrate as energy source. Glucose was used as the primary energy source during the glucose-citrate diauxie. Uptake of citrate was carried out by an inducible citrate transport system. The induction of citrate uptake system was repressed in the presence of glucose. This repression was reversible and mediated by cAMP.

21 CFR 582.5195 - Calcium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance...

21 CFR 582.5195 - Calcium citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance...

21 CFR 582.5195 - Calcium citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance...

21 CFR 582.5195 - Calcium citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance...

21 CFR 582.1195 - Calcium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Additives § 582.1195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding practice. ...

21 CFR 582.5195 - Calcium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance...

21 CFR 582.1195 - Calcium citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Additives § 582.1195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding practice. ...

21 CFR 582.1195 - Calcium citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Additives § 582.1195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding practice. ...

21 CFR 582.1195 - Calcium citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Additives § 582.1195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding practice. ...

21 CFR 582.6851 - Stearyl citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Stearyl citrate. (a) Product. Stearyl citrate. (b) Tolerance. This substance is generally recognized as safe for use at a level not exceeding 0.15 percent in accordance with good manufacturing or feeding...

21 CFR 582.6386 - Isopropyl citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Isopropyl citrate. (a) Product. Isopropyl citrate. (b) Tolerance. This substance is generally recognized as safe for use at a level not exceeding 0.02 percent in accordance with good manufacturing or feeding...

Aspergillus niger Secretes Citrate to Increase Iron Bioavailability

PubMed Central

Odoni, Dorett I.; van Gaal, Merlijn P.; Schonewille, Tom; Tamayo-Ramos, Juan A.; Martins dos Santos, Vitor A. P.; Suarez-Diez, Maria; Schaap, Peter J.

2017-01-01

Aspergillus niger has an innate ability to secrete various organic acids, including citrate. The conditions required for A. niger citrate overproduction are well described, but the physiological reasons underlying extracellular citrate accumulation are not yet fully understood. One of the less understood culture conditions is the requirement of growth-limiting iron concentrations. While this has been attributed to iron-dependent citrate metabolizing enzymes, this straightforward relationship does not always hold true. Here, we show that an increase in citrate secretion under iron limited conditions is a physiological response consistent with a role of citrate as A. niger iron siderophore. We found that A. niger citrate secretion increases with decreasing amounts of iron added to the culture medium and, in contrast to previous findings, this response is independent of the nitrogen source. Differential transcriptomics analyses of the two A. niger mutants NW305 (gluconate non-producer) and NW186 (gluconate and oxalate non-producer) revealed up-regulation of the citrate biosynthesis gene citA under iron limited conditions compared to iron replete conditions. In addition, we show that A. niger can utilize Fe(III) citrate as iron source. Finally, we discuss our findings in the general context of the pH-dependency of A. niger organic acid production, offering an explanation, besides competition, for why A. niger organic acid production is a sequential process influenced by the external pH of the culture medium. PMID:28824560

21 CFR 522.800 - Droperidol and fentanyl citrate injection.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Droperidol and fentanyl citrate injection. 522.800... § 522.800 Droperidol and fentanyl citrate injection. (a) Specifications. Droperidol and fentanyl citrate injection is a sterile solution containing 20 milligrams of droperidol and 0.4 milligram of fentanyl citrate...

21 CFR 522.800 - Droperidol and fentanyl citrate injection.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Droperidol and fentanyl citrate injection. 522.800... § 522.800 Droperidol and fentanyl citrate injection. (a) Specifications. Droperidol and fentanyl citrate injection is a sterile solution containing 20 milligrams of droperidol and 0.4 milligram of fentanyl citrate...

21 CFR 522.800 - Droperidol and fentanyl citrate injection.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Droperidol and fentanyl citrate injection. 522.800... § 522.800 Droperidol and fentanyl citrate injection. (a) Specifications. Droperidol and fentanyl citrate injection is a sterile solution containing 20 milligrams of droperidol and 0.4 milligram of fentanyl citrate...

Citrate Pharmacokinetics in Critically Ill Patients with Acute Kidney Injury

PubMed Central

Zhu, Qiuyu; Liu, Junfeng; Qian, Jing; You, Huaizhou; Gu, Yong; Hao, Chuanming; Jiao, Zheng; Ding, Feng

2013-01-01

Introduction Regional citrate anticoagulation (RCA) is gaining popularity in continous renal replacement therapy (CRRT) for critically ill patients. The risk of citrate toxicity is a primary concern during the prolonged process. The aim of this study was to assess the pharmacokinetics of citrate in critically ill patients with AKI, and used the kinetic parameters to predict the risk of citrate accumulation in this population group undergoing continuous veno-venous hemofiltration (CVVH) with RCA. Methods Critically ill patients with AKI (n = 12) and healthy volunteers (n = 12) were investigated during infusing comparative dosage of citrate. Serial blood samples were taken before, during 120 min and up to 120 min after infusion. Citrate pharmacokinetics were calculated and compared between groups. Then the estimated kinetic parameters were applied to the citrate kinetic equation for validation in other ten patients’ CVVH sessions with citrate anticoagulation. Results Total body clearance of citrate was similar in critically ill patients with AKI and healthy volunteers (648.04±347.00 L/min versus 686.64±353.60 L/min; P = 0.624). Basal and peak citrate concentrations were similar in both groups (p = 0.423 and 0.247, respectively). The predicted citrate curve showed excellent fit to the measurements. Conclusions Citrate clearance is not impaired in critically ill patients with AKI in the absence of severe liver dysfunction. Citrate pharmacokinetic data can provide a basis for the clinical use of predicting the risk of citrate accumulation. Trial Registration ClinicalTrials.gov Identifier NCT00948558 PMID:23824037

Aluminum-activated citrate and malate transporters from the MATE and ALMT families function independently to confer Arabidopsis aluminum tolerance.

PubMed

Liu, Jiping; Magalhaes, Jurandir V; Shaff, Jon; Kochian, Leon V

2009-02-01

Aluminum-activated root malate and citrate exudation play an important role in plant Al tolerance. This paper characterizes AtMATE, a homolog of the recently discovered sorghum and barley Al-tolerance genes, shown here to encode an Al-activated citrate transporter in Arabidopsis. Together with the previously characterized Al-activated malate transporter, AtALMT1, this discovery allowed us to examine the relationship in the same species between members of the two gene families for which Al-tolerance genes have been identified. AtMATE is expressed primarily in roots and is induced by Al. An AtMATE T-DNA knockdown line exhibited very low AtMATE expression and Al-activated root citrate exudation was abolished. The AtALMT1 AtMATE double mutant lacked both Al-activated root malate and citrate exudation and showed greater Al sensitivity than the AtALMT1 mutant. Therefore, although AtALMT1 is a major contributor to Arabidopsis Al tolerance, AtMATE also makes a significant but smaller contribution. The expression patterns of AtALMT1 and AtMATE and the profiles of Al-activated root citrate and malate exudation are not affected by the presence or absence of the other gene. These results suggest that AtALMT1-mediated malate exudation and AtMATE-mediated citrate exudation evolved independently to confer Al tolerance in Arabidopsis. However, a link between regulation of expression of the two transporters in response to Al was identified through work on STOP1, a transcription factor that was previously shown to be necessary for AtALMT1 expression. Here we show that STOP1 is also required for AtMATE expression and Al-activated citrate exudation.

Comparison of the Absorption of Calcium Carbonate and Calcium Citrate after Roux-en-Y Gastric Bypass

PubMed Central

Tondapu, P.; Provost, D.; Adams-Huet, B.; Sims, T.; Chang, C.; Sakhaee, K.

2015-01-01

Introduction Roux-en-Y gastric bypass (RYGB) restricts food intake. Consequently, patients consume less calcium. In addition, food no longer passes through the duodenum, the main site of calcium absorption. Therefore, calcium absorption is significantly impaired. The goal of this study is to compare two common calcium supplements in gastric bypass patients. Method Nineteen patients were enrolled in a randomized, double-blinded, crossover study comparing the absorption of calcium from calcium carbonate and calcium citrate salts. Serum and urine calcium levels were assessed for peak values (Cmax) and cumulative calcium increment (area under the curve [AUC]). Serum PTH was assessed for minimum values (PTHmin) and cumulative PTH decrement (AUC). Statistical analysis was performed using a repeated analysis of variance model. Results Eighteen subjects completed the study. Calcium citrate resulted in a significantly higher serum Cmax (9.4+0.4 mg/dl vs. 9.2+0.3 mg/dl, p=0.02) and serum AUC (55+2 mg/dl vs. 54+2 mg/dl, p=0.02). Calcium citrate resulted in a significantly lower PTHmin (24+11 pg/ml vs. 30+13 pg/ml, p=0.01) and a higher AUC (−32+51 pg/ml vs. −3+56 pg/ml, p=0.04). There was a non-significant trend for higher urinary AUC in the calcium citrate group (76.13+36.39 mg/6 h vs. 66.04+40.82, p=0.17). Conclusion Calcium citrate has superior bioavailability than calcium carbonate in RYGB patients. PMID:19437082

SbnG, a Citrate Synthase in Staphylococcus aureus

PubMed Central

Kobylarz, Marek J.; Grigg, Jason C.; Sheldon, Jessica R.; Heinrichs, David E.; Murphy, Michael E. P.

2014-01-01

In response to iron deprivation, Staphylococcus aureus produces staphyloferrin B, a citrate-containing siderophore that delivers iron back to the cell. This bacterium also possesses a second citrate synthase, SbnG, that is necessary for supplying citrate to the staphyloferrin B biosynthetic pathway. We present the structure of SbnG bound to the inhibitor calcium and an active site variant in complex with oxaloacetate. The overall fold of SbnG is structurally distinct from TCA cycle citrate synthases yet similar to metal-dependent class II aldolases. Phylogenetic analyses revealed that SbnG forms a separate clade with homologs from other siderophore biosynthetic gene clusters and is representative of a metal-independent subgroup in the phosphoenolpyruvate/pyruvate domain superfamily. A structural superposition of the SbnG active site to TCA cycle citrate synthases and site-directed mutagenesis suggests a case for convergent evolution toward a conserved catalytic mechanism for citrate production. PMID:25336653

21 CFR 172.370 - Iron-choline citrate complex.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Iron-choline citrate complex. 172.370 Section 172... CONSUMPTION Special Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline citrate complex made by reacting approximately equimolecular quantities of ferric hydroxide, choline, and...

21 CFR 573.580 - Iron-choline citrate complex.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Iron-choline citrate complex. 573.580 Section 573...

21 CFR 573.580 - Iron-choline citrate complex.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Iron-choline citrate complex. 573.580 Section 573...

21 CFR 573.580 - Iron-choline citrate complex.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Iron-choline citrate complex. 573.580 Section 573...

21 CFR 573.580 - Iron-choline citrate complex.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Iron-choline citrate complex. 573.580 Section 573...

21 CFR 573.580 - Iron-choline citrate complex.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Iron-choline citrate complex. 573.580 Section 573...

Citrate chemistry and biology for biomaterials design.

PubMed

Ma, Chuying; Gerhard, Ethan; Lu, Di; Yang, Jian

2018-05-04

Leveraging the multifunctional nature of citrate in chemistry and inspired by its important role in biological tissues, a class of highly versatile and functional citrate-based materials (CBBs) has been developed via facile and cost-effective polycondensation. CBBs exhibiting tunable mechanical properties and degradation rates, together with excellent biocompatibility and processability, have been successfully applied in vitro and in vivo for applications ranging from soft to hard tissue regeneration, as well as for nanomedicine designs. We summarize in the review, chemistry considerations for CBBs design to tune polymer properties and to introduce functionality with a focus on the most recent advances, biological functions of citrate in native tissues with the new notion of degradation products as cell modulator highlighted, and the applications of CBBs in wound healing, nanomedicine, orthopedic, cardiovascular, nerve and bladder tissue engineering. Given the expansive evidence for citrate's potential in biology and biomaterial science outlined in this review, it is expected that citrate based materials will continue to play an important role in regenerative engineering. Copyright © 2018 Elsevier Ltd. All rights reserved.

The electronic structure and optical properties of ABP 2O 7 ( A = Na, Li) double phosphates

NASA Astrophysics Data System (ADS)

Hizhnyi, Yu. A.; Oliynyk, A.; Gomenyuk, O.; Nedilko, S. G.; Nagornyi, P.; Bojko, R.; Bojko, V.

2008-01-01

Partial densities of states and reflection spectra of NaAlP 2O 7, KAlP 2O 7 and LiInP 2O 7 double phosphate crystals are calculated by the full-potential linear-augmented-plane-wave (FLAPW) method. Experimental reflection spectra of KAlP 2O 7, CsAlP 2O 7 and NaInP 2O 7 are measured in the 4-20 eV energy range. The values of band gaps, Eg, are found from a comparison of experiment and calculations to be 6.0 eV for NaAlP 2O 7 and KAlP 2O 7, and 4.6 eV for LiInP 2O 7.

Effect of potential renal acid load of foods on urinary citrate excretion in calcium renal stone formers.

PubMed

Trinchieri, Alberto; Lizzano, Renata; Marchesotti, Federica; Zanetti, Giampaolo

2006-02-01

The aim of this study was to investigate the influence of the potential renal acid load (PRAL) of the diet on the urinary risk factors for renal stone formation. The present series comprises 187 consecutive renal calcium stone patients (114 males, 73 females) who were studied in our stone clinic. Each patient was subjected to an investigation including a 24-h dietary record and 24-h urine sample taken over the same period. Nutrients and calories were calculated by means of food composition tables using a computerized procedure. Daily PRAL was calculated considering the mineral and protein composition of foods, the mean intestinal absorption rate for each nutrient and the metabolism of sulfur-containing amino acids. Sodium, potassium, calcium, magnesium, phosphate, oxalate, urate, citrate, and creatinine levels were measured in the urine. The mean daily PRAL was higher in male than in female patients (24.1+/-24.0 vs 16.1+/-20.1 mEq/day, P=0.000). A significantly (P=0.01) negative correlation (R=-0.18) was found between daily PRAL and daily urinary citrate, but no correlation between PRAL and urinary calcium, oxalate, and urate was shown. Daily urinary calcium (R=0.186, P=0.011) and uric acid (R=0.157, P=0.033) were significantly related to the dietary intake of protein. Daily urinary citrate was significantly related to the intakes of copper (R=0.178, P=0.015), riboflavin (R=0.20, P=0.006), piridoxine (R=0.169, P=0.021) and biotin (R=0.196, P=0.007). The regression analysis by stepwise selection confirmed the significant negative correlation between PRAL and urinary citrate (P=0.002) and the significant positive correlation between riboflavin and urinary citrate (P=0.000). Urinary citrate excretion of renal stone formers (RSFs) is highly dependent from dietary acid load. The computation of the renal acid load is advisable to investigate the role of diet in the pathogenesis of calcium stone disease and it is also a useful tool to evaluate the lithogenic potential of

Ca2+-Citrate Uptake and Metabolism in Lactobacillus casei ATCC 334

PubMed Central

Mortera, Pablo; Pudlik, Agata; Magni, Christian; Alarcón, Sergio

2013-01-01

The putative citrate metabolic pathway in Lactobacillus casei ATCC 334 consists of the transporter CitH, a proton symporter of the citrate-divalent metal ion family of transporters CitMHS, citrate lyase, and the membrane-bound oxaloacetate decarboxylase complex OAD-ABDH. Resting cells of Lactobacillus casei ATCC 334 metabolized citrate in complex with Ca2+ and not as free citrate or the Mg2+-citrate complex, thereby identifying Ca2+-citrate as the substrate of the transporter CitH. The pathway was induced in the presence of Ca2+ and citrate during growth and repressed by the presence of glucose and of galactose, most likely by a carbon catabolite repression mechanism. The end products of Ca2+-citrate metabolism by resting cells of Lb. casei were pyruvate, acetate, and acetoin, demonstrating the activity of the membrane-bound oxaloacetate decarboxylase complex OAD-ABDH. Following pyruvate, the pathway splits into two branches. One branch is the classical citrate fermentation pathway producing acetoin by α-acetolactate synthase and α-acetolactate decarboxylase. The other branch yields acetate, for which the route is still obscure. Ca2+-citrate metabolism in a modified MRS medium lacking a carbohydrate did not significantly affect the growth characteristics, and generation of metabolic energy in the form of proton motive force (PMF) was not observed in resting cells. In contrast, carbohydrate/Ca2+-citrate cometabolism resulted in a higher biomass yield in batch culture. However, also with these cells, no generation of PMF was associated with Ca2+-citrate metabolism. It is concluded that citrate metabolism in Lb. casei is beneficial when it counteracts acidification by carbohydrate metabolism in later growth stages. PMID:23709502

Enhanced dissolution of sildenafil citrate as dry foam tablets.

PubMed

Sawatdee, Somchai; Atipairin, Apichart; Sae Yoon, Attawadee; Srichana, Teerapol; Changsan, Narumon

2017-01-30

Dry foam formulation technology is alternative approach to enhance dissolution of the drug. Sildenafil citrate was suspended in sodium dodecyl sulfate solution and adding a mixture of maltodextrin and mannitol as diluent to form a paste. Sildenafil citrate paste was passed through a nozzle spray bottle to obtain smooth foam. The homogeneous foam was dried in a vacuum oven and sieved to obtain dry foam granules. The granules were mixed with croscarmellose sodium, magnesium stearate and compressed into tablet. All formulations were evaluated for their physicochemical properties and dissolution profiles. All the tested excipients were compatible with sildenafil citrate by both differential scanning calorimetry (DSC) and infrared (IR) analysis. There are no X-ray diffraction (XRD) peaks representing crystals of sildenafil citrate observed form dry foam formulations. The hardness of tablets was about 5 kg, friability test <1% with a disintegration time <5 min. The sildenafil citrate dry foam tablet had higher dissolution rate in 0.1 N HCl in comparison with commercial sildenafil citrate tablet, sildenafil citrate prepared by direct compression and wet granulation method. Sildenafil citrate dry foam tablet with the high-level composition of surfactant, water and diluent showed enhanced dissolution rate than that of the lower-level composition of these excipients. This formulation was stable under accelerated conditions for at least 6 months.

Comparison of the efficiency of clomiphene citrate and letrozole in combination with metformin in moderately obese clomiphene citrate-resistant polycystic ovarian syndrome patients.

PubMed

Bjelica, Artur; Trninić-Pjević, Aleksandra; Mladenović-Segedi, Ljiljana; Cetković, Nenad; Petrović, Djordje

2016-01-01

Polycystic ovary syndrome is the most common endocrinopathy in women of reproductive-age. Therapy for those who want to get pregnant involves ovulation induction using clomiphene citrate, metformin, letrozole and gonadotropins. The aim of the study was to compare the efficacy of combinations of clomiphene citrate-metformin and letrozole-metformin in obese patients who are resistant to clomiphene citrate alone. The investigation was conducted as a retrospective study involving 60 moderately obese patients with polycystic ovary syndrome. Thirty-one of them received the clomiphene citrate-metformin, and 29 letrozole-metformin therapy. Stimulation was carried out for the procedures of intrauterine insemination (IUI). The age of patients, duration of infertility, and body mass index in both groups were similar. There was statistically significant difference in the thickness of the endometrium in favor of the group having the letrozole-metformin therapy (8.9 ± 1.7 mm) compared with the group receiving the clomiphene citrate-metformin treatment (6.3 ± 1.3 mm). The number of follicles was not statistically significantly different. Pregnancy rate in the first cycle of IUI in the clomiphene citrate group was 6.4%, and 17.2% in the letrozole group, which also was not statistically different. After the third IUI cycle, the pregnancy rate was significantly higher in the letrozole group (20.6%), while in the clomiphene citrate group it was (9.6%). This retrospective study demonstrated the advantages of the use of letrozole over clomiphene citrate in combination with metformin in moderately obese patients with polycystic ovary syndrome who are resistant to stimulation with clomiphene citrate alone.

Enclomiphene Citrate for the Treatment of Secondary Male Hypogonadism

PubMed Central

Rodriguez, Katherine M.; Pastuszak, Alexander W.; Lipshultz, Larry I.

2016-01-01

Introduction Hypogonadism is a growing concern in an aging male population. Historically treated using exogenous testosterone, concerns about possible adverse effects of testosterone have led physicians to seek alternative treatment approaches. Areas Covered Enclomiphene citrate is the trans isomer of clomiphene citrate, a non-steroidal estrogen receptor antagonist that is FDA-approved for the treatment of ovarian dysfunction in women. Clomiphene citrate has also been used off-label for many years to treat secondary male hypogonadism, particularly in the setting of male infertility. Here we review the literature examining the efficacy and safety of enclomiphene citrate in the setting of androgen deficiency. Expert Opinion Initial results support the conclusion that enclomiphene citrate increases serum testosterone levels by raising luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels, without negatively impacting semen parameters. The ability to treat testosterone deficiency in men while maintaining fertility supports a role for enclomiphene citrate in the treatment of men in whom testosterone therapy is not a suitable option. PMID:27337642

Zinc Absorption by Young Adults from Supplemental Zinc Citrate Is Comparable with That from Zinc Gluconate and Higher than from Zinc Oxide123

PubMed Central

Wegmüller, Rita; Tay, Fabian; Zeder, Christophe; Brnić, Marica; Hurrell, Richard F.

2014-01-01

The water-soluble zinc salts gluconate, sulfate, and acetate are commonly used as supplements in tablet or syrup form to prevent zinc deficiency and to treat diarrhea in children in combination with oral rehydration. Zinc citrate is an alternative compound with high zinc content, slightly soluble in water, which has better sensory properties in syrups but no absorption data in humans. We used the double-isotope tracer method with 67Zn and 70Zn to measure zinc absorption from zinc citrate given as supplements containing 10 mg of zinc to 15 healthy adults without food and compared absorption with that from zinc gluconate and zinc oxide (insoluble in water) using a randomized, double-masked, 3-way crossover design. Median (IQR) fractional absorption of zinc from zinc citrate was 61.3% (56.6–71.0) and was not different from that from zinc gluconate with 60.9% (50.6–71.7). Absorption from zinc oxide at 49.9% (40.9–57.7) was significantly lower than from both other supplements (P < 0.01). Three participants had little or no absorption from zinc oxide. We conclude that zinc citrate, given as a supplement without food, is as well absorbed by healthy adults as zinc gluconate and may thus be a useful alternative for preventing zinc deficiency and treating diarrhea. The more insoluble zinc oxide is less well absorbed when given as a supplement without food and may be minimally absorbed by some individuals. This trial was registered at clinicaltrials.gov as NCT01576627. PMID:24259556

Antitumor effect and toxicity of free rhodium (II) citrate and rhodium (II) citrate-loaded maghemite nanoparticles in mice bearing breast cancer.

PubMed

Carneiro, Marcella Lemos Brettas; Peixoto, Raphael C A; Joanitti, Graziela A; Oliveira, Ricardo G S; Telles, Luis A M; Miranda-Vilela, Ana L; Bocca, Anamélia L; Vianna, Leonora M S; da Silva, Izabel C R; de Souza, Aparecido R; Lacava, Zulmira G M; Báo, Sônia N

2013-02-16

Magnetic fluids containing superparamagnetic iron oxide nanoparticles represent an attractive platform as nanocarriers in chemotherapy. Recently, we developed a formulation of maghemite nanoparticles coated with rhodium (II) citrate, which resulted in in vitro cytotoxicity enhanced up to 4.6 times when compared to free rhodium (II) citrate formulation on breast carcinoma cells. In this work, we evaluate the antitumor activity and toxicity induced by these formulations in Balb/c mice bearing orthotopic 4T1 breast carcinoma. Mice were evaluated with regard to the treatments' toxicity through analyses of hemogram, serum levels of alanine aminotransferase, iron, and creatinine; DNA fragmentation and cell cycle of bone marrow cells; and liver, kidney and lung histology. In addition, the antitumor activity of rhodium (II) citrate and maghemite nanoparticles coated with rhodium (II) citrate was verified by tumor volume reduction, histology and immunohistochemistry. Regarding the treatments' toxicity, no experimental groups had alterations in levels of serum ALT or creatinine, and this suggestion was corroborated by the histopathologic examination of liver and kidney of mice. Moreover, DNA fragmentation frequency of bone marrow cells was lower than 15% in all experimental groups. On the other hand, the complexes rhodium (II) citrate-functionalized maghemite and free rhodium (II) citrate led to a marked growth inhibition of tumor and decrease in CD31 and Ki-67 staining. In summary, we demonstrated that both rhodium (II) citrate and maghemite nanoparticles coated with rhodium (II) citrate formulations exhibited antitumor effects against 4T1 metastatic breast cancer cell line following intratumoral administration. This antitumor effect was followed by inhibition of both cell proliferation and microvascularization and by tumor tissue injury characterized as necrosis and fibrosis. Remarkably, this is the first published report demonstrating the therapeutic efficacy of maghemite

Antitumor effect and toxicity of free rhodium (II) citrate and rhodium (II) citrate-loaded maghemite nanoparticles in mice bearing breast cancer

PubMed Central

2013-01-01

Background Magnetic fluids containing superparamagnetic iron oxide nanoparticles represent an attractive platform as nanocarriers in chemotherapy. Recently, we developed a formulation of maghemite nanoparticles coated with rhodium (II) citrate, which resulted in in vitro cytotoxicity enhanced up to 4.6 times when compared to free rhodium (II) citrate formulation on breast carcinoma cells. In this work, we evaluate the antitumor activity and toxicity induced by these formulations in Balb/c mice bearing orthotopic 4T1 breast carcinoma. Methods Mice were evaluated with regard to the treatments’ toxicity through analyses of hemogram, serum levels of alanine aminotransferase, iron, and creatinine; DNA fragmentation and cell cycle of bone marrow cells; and liver, kidney and lung histology. In addition, the antitumor activity of rhodium (II) citrate and maghemite nanoparticles coated with rhodium (II) citrate was verified by tumor volume reduction, histology and immunohistochemistry. Results Regarding the treatments’ toxicity, no experimental groups had alterations in levels of serum ALT or creatinine, and this suggestion was corroborated by the histopathologic examination of liver and kidney of mice. Moreover, DNA fragmentation frequency of bone marrow cells was lower than 15% in all experimental groups. On the other hand, the complexes rhodium (II) citrate-functionalized maghemite and free rhodium (II) citrate led to a marked growth inhibition of tumor and decrease in CD31 and Ki-67 staining. Conclusions In summary, we demonstrated that both rhodium (II) citrate and maghemite nanoparticles coated with rhodium (II) citrate formulations exhibited antitumor effects against 4T1 metastatic breast cancer cell line following intratumoral administration. This antitumor effect was followed by inhibition of both cell proliferation and microvascularization and by tumor tissue injury characterized as necrosis and fibrosis. Remarkably, this is the first published report

The regulatory network of cluster-root function and development in phosphate-deficient white lupin (Lupinus albus) identified by transcriptome sequencing.

PubMed

Wang, Zhengrui; Straub, Daniel; Yang, Huaiyu; Kania, Angelika; Shen, Jianbo; Ludewig, Uwe; Neumann, Günter

2014-07-01

Lupinus albus serves as model plant for root-induced mobilization of sparingly soluble soil phosphates via the formation of cluster-roots (CRs) that mediate secretion of protons, citrate, phenolics and acid phosphatases (APases). This study employed next-generation sequencing to investigate the molecular mechanisms behind these complex adaptive responses at the transcriptome level. We compared different stages of CR development, including pre-emergent (PE), juvenile (JU) and the mature (MA) stages. The results confirmed that the primary metabolism underwent significant modifications during CR maturation, promoting the biosynthesis of organic acids, as had been deduced from physiological studies. Citrate catabolism was downregulated, associated with citrate accumulation in MA clusters. Upregulation of the phenylpropanoid pathway reflected the accumulation of phenolics. Specific transcript expression of ALMT and MATE transporter genes correlated with the exudation of citrate and flavonoids. The expression of transcripts related to nucleotide degradation and APases in MA clusters coincided with the re-mobilization and hydrolysis of organic phosphate resources. Most interestingly, hormone-related gene expression suggested a central role of ethylene during CR maturation. This was associated with the upregulation of the iron (Fe)-deficiency regulated network that mediates ethylene-induced expression of Fe-deficiency responses in other species. Finally, transcripts related to abscisic acid and jasmonic acid were upregulated in MA clusters, while auxin- and brassinosteroid-related genes and cytokinin receptors were most strongly expressed during CR initiation. Key regulations proposed by the RNA-seq data were confirmed by quantitative real-time polymerase chain reaction (RT-qPCR) and some physiological analyses. A model for the gene network regulating CR development and function is presented. © 2014 Scandinavian Plant Physiology Society.

Aluminum Citrate Prevents Renal Injury from Calcium Oxalate Crystal Deposition

PubMed Central

Besenhofer, Lauren M.; Cain, Marie C.; Dunning, Cody

2012-01-01

Calcium oxalate monohydrate crystals are responsible for the kidney injury associated with exposure to ethylene glycol or severe hyperoxaluria. Current treatment strategies target the formation of calcium oxalate but not its interaction with kidney tissue. Because aluminum citrate blocks calcium oxalate binding and toxicity in human kidney cells, it may provide a different therapeutic approach to calcium oxalate-induced injury. Here, we tested the effects of aluminum citrate and sodium citrate in a Wistar rat model of acute high-dose ethylene glycol exposure. Aluminum citrate, but not sodium citrate, attenuated increases in urea nitrogen, creatinine, and the ratio of kidney to body weight in ethylene glycol–treated rats. Compared with ethylene glycol alone, the addition of aluminum citrate significantly increased the urinary excretion of both crystalline calcium and crystalline oxalate and decreased the deposition of crystals in renal tissue. In vitro, aluminum citrate interacted directly with oxalate crystals to inhibit their uptake by proximal tubule cells. These results suggest that treating with aluminum citrate attenuates renal injury in rats with severe ethylene glycol toxicity, apparently by inhibiting calcium oxalate’s interaction with, and retention by, the kidney epithelium. PMID:23138489

Cyclic-2,3-diphosphoglycerate levels in Methanobacterium thermoautotrophicum reflect inorganic phosphate availability.

PubMed

Seely, R J; Krueger, R D; Fahrney, D E

1983-11-15

Methanobacterium thermoautotrophicum was grown in phosphate-limited chemostat cultures at a dilution rate corresponding to a doubling time of 13.2 h. The cyclic-2,3-diphospho-D-glycerate content of these cells was 8 to 10-fold lower than that of cells grown in batch cultures having a doubling time of 11.5 h. This metabolite accounted for 5% of cell dry weight during batch growth on 2 mM phosphate. In the chemostat the steady-state concentration of phosphate was 4 microM, showing that this methanogen is adapted to highly efficient growth at low phosphate concentrations. Since growth rates were similar in both cultures, the growth rate clearly does not depend on intracellular levels of cyclic-2,3-diphosphoglycerate.

TRANSFUSIONS—Hazardous Acid-Base Changes with Citrated Blood

PubMed Central

Pedro, Jovita M. San; Iwai, Seizo; Hattori, Mitsuo; Leigh, M. Digby

1962-01-01

In a study of the acid-base changes in the blood of rabbits during and following transfusions of citrated blood and of heparinized blood, it was observed that, with citrated blood, pH decreased and carbon dioxide tensions rose. With heparinized blood, the acid-base balance was maintained within normal limits following transfusions. The potential hazards of rapid massive citrated blood transfusions in the anesthetized patient during operation must be kept in mind. PMID:14496706

Alkali absorption and citrate excretion in calcium nephrolithiasis

NASA Technical Reports Server (NTRS)

Sakhaee, K.; Williams, R. H.; Oh, M. S.; Padalino, P.; Adams-Huet, B.; Whitson, P.; Pak, C. Y.

1993-01-01

The role of net gastrointestinal (GI) alkali absorption in the development of hypocitraturia was investigated. The net GI absorption of alkali was estimated from the difference between simple urinary cations (Ca, Mg, Na, and K) and anions (Cl and P). In 131 normal subjects, the 24 h urinary citrate was positively correlated with the net GI absorption of alkali (r = 0.49, p < 0.001). In 11 patients with distal renal tubular acidosis (RTA), urinary citrate excretion was subnormal relative to net GI alkali absorption, with data from most patients residing outside the 95% confidence ellipse described for normal subjects. However, the normal relationship between urinary citrate and net absorbed alkali was maintained in 11 patients with chronic diarrheal syndrome (CDS) and in 124 stone-forming patients devoid of RTA or CDS, half of whom had "idiopathic" hypocitraturia. The 18 stone-forming patients without RTA or CDS received potassium citrate (30-60 mEq/day). Both urinary citrate and net GI alkali absorption increased, yielding a significantly positive correlation (r = 0.62, p < 0.0001), with the slope indistinguishable from that of normal subjects. Thus, urinary citrate was normally dependent on the net GI absorption of alkali. This dependence was less marked in RTA, confirming the renal origin of hypocitraturia. However, the normal dependence was maintained in CDS and in idiopathic hypocitraturia, suggesting that reduced citrate excretion was largely dietary in origin as a result of low net alkali absorption (from a probable relative deficiency of vegetables and fruits or a relative excess of animal proteins).

21 CFR 172.755 - Stearyl monoglyceridyl citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Other Specific Usage Additives § 172.755 Stearyl monoglyceridyl citrate. The food additive stearyl monoglyceridyl citrate may be safely used in food in accordance with the following...

21 CFR 172.755 - Stearyl monoglyceridyl citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Other Specific Usage Additives § 172.755 Stearyl monoglyceridyl citrate. The food additive stearyl monoglyceridyl citrate may be safely used in food in accordance with the following...

21 CFR 172.370 - Iron-choline citrate complex.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline citrate complex made by reacting...

21 CFR 73.1025 - Ferric ammonium citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Ferric ammonium citrate. 73.1025 Section 73.1025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1025 Ferric ammonium citrate. (a) Identity. The...

21 CFR 73.1025 - Ferric ammonium citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Ferric ammonium citrate. 73.1025 Section 73.1025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1025 Ferric ammonium citrate. (a) Identity. The...

21 CFR 73.1025 - Ferric ammonium citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Ferric ammonium citrate. 73.1025 Section 73.1025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1025 Ferric ammonium citrate. (a) Identity. The...

21 CFR 73.1025 - Ferric ammonium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Ferric ammonium citrate. 73.1025 Section 73.1025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1025 Ferric ammonium citrate. (a) Identity. The...

21 CFR 73.1025 - Ferric ammonium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Ferric ammonium citrate. 73.1025 Section 73.1025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1025 Ferric ammonium citrate. (a) Identity. The...

Improved Recovery of Hepatocytes Isolated From Warm Ischemic Rat Liver by Citrate Phosphate Dextrose (CPD)-Supplemented Euro-Collins Solution

PubMed Central

Hsu, Huai-Che; Matsuno, Naoto; Machida, Noboru; Enosawa, Shin

2013-01-01

Demand for human primary hepatocytes is increasing, particularly for clinical trials of hepatocyte transplantation. However, due to the severe shortage of organ transplant donors, the source of cells for these endeavors is restricted to untransplantable livers, such as those from non-heart-beating donors and surgically resected liver tissues. To improve cell recovery from such sources after warm ischemia, we evaluated the efficacy of applying perfusion solutions, focusing on improvement of hepatocyte recovery. Warm ischemia was induced by clamping both portal vein and hepatic artery for 10 or 15 min in rats. The liver was perfused with either Euro-Collins (EC) or extracellular-type trehalose-containing Kyoto (ETK) solutions supplemented with an anticoagulant, either heparin or citrate phosphate dextrose solution (CPD), compared to Ca2+, Mg2+-free Hanks solution. While the viability of recovered cells was 81.5 ± 4.2% and cell yield was 2.27 ± 0.53 × 108 in nonwarm ischemia controls (n = 11), these values were only 74.7 ± 2.9% and 0.38 ± 0.17 × 108, respectively, in the 10-min warm ischemia group, using the Hanks as the perfusion solution. Although the addition of heparin increased the live cell number only twofold (0.71 ± 0.40 × 108, n = 4), the best improvement was achieved by adding CPD to EC. This resulted in a recovery of 1.41 ± 0.50 × 108 in the 10-min ischemia group (n = 7) and 1.37 ± 0.28 × 108 in the 15-min group (n = 3). Macroscopic observation showed that blood had been completely flushed out by the solution, suggesting good restoration of the microcirculation in ischemic liver. Using ETK instead of EC resulted in a slight decrease in efficacy. These results demonstrate that CPD, as opposed to heparin, is effective in ensuring liver microcirculation and flushing out the blood and that EC is the best perfusion solution for obtaining hepatocytes from ischemic liver. PMID:26858872

[Mechanical properties of polylactic acid/beta-tricalcium phosphate composite scaffold with double channels based on three-dimensional printing technique].

PubMed

Lian, Qin; Zhuang, Pei; Li, Changhai; Jin, Zhongmin; Li, Dichen

2014-03-01

To improve the poor mechanical strength of porous ceramic scaffold, an integrated method based on three-dimensional (3-D) printing technique is developed to incorporate the controlled double-channel porous structure into the polylactic acid/beta-tricalcium phosphate (PLA/beta-TCP) reinforced composite scaffolds (double-channel composite scaffold) to improve their tissue regeneration capability and the mechanical properties. The designed double-channel structure inside the ceramic scaffold consisted of both primary and secondary micropipes, which parallel but un-connected. The set of primary channels was used for cell ingrowth, while the set of secondary channels was used for the PLA perfusion. Integration technology of 3-D printing technique and gel-casting was firstly used to fabricate the double-channel ceramic scaffolds. PLA/beta-TCP composite scaffolds were obtained by the polymer gravity perfusion process to pour PLA solution into the double-channel ceramic scaffolds through the secondary channel set. Microscope, porosity, and mechanical experiments for the standard samples were used to evaluate the composite properties. The ceramic scaffold with only the primary channel (single-channel scaffold) was also prepared as a control. Morphology observation results showed that there was no PLA inside the primary channels of the double-channel composite scaffolds but a dense interface layer between PLA and beta-TCP obviously formed on the inner wall of the secondary channels by the PLA penetration during the perfusion process. Finite element simulation found that the compressive strength of the double-channel composite scaffold was less than that of the single-channel scaffold; however, mechanical tests found that the maximum compressive strength of the double-channel composite scaffold [(21.25 +/- 1.15) MPa] was higher than that of the single-channel scaffold[ (9.76 +/- 0.64) MPa]. The double-channel composite scaffolds fabricated by 3-D printing technique have

Deletion of Citrate Synthase Restores Growth of Sinorhizobium meliloti 1021 Aconitase Mutants▿

PubMed Central

Koziol, Uriel; Hannibal, Luciana; Rodríguez, María Cecilia; Fabiano, Elena; Kahn, Michael L.; Noya, Francisco

2009-01-01

The symbiotic nitrogen-fixing bacterium Sinorhizobium meliloti 1021 encodes only one predicted aconitase (AcnA) in its genome. AcnA has a significant degree of similarity with other bacterial aconitases that behave as dual proteins: enzymes and posttranscriptional regulators of gene expression. Similar to the case with these bacterial aconitases, AcnA activity was reversibly labile and was regained upon reconstitution with reduced iron. The aconitase promoter was active in root nodules. acnA mutants grew very poorly, had secondary mutations, and were quickly outgrown by pseudorevertants. The acnA gene was stably interrupted in a citrate synthase (gltA) null background, indicating that the intracellular accumulation of citrate may be deleterious for survival of strain 1021. No aconitase activity was detected in this mutant, suggesting that the acnA gene encodes the only functional aconitase of strain 1021. To uncover a function of AcnA beyond its catalytic role in the tricarboxylic acid cycle pathway, the gltA acnA double mutant was compared with the gltA single mutant for differences in motility, resistance to oxidative stress, nodulation, and growth on different substrates. However, no differences in any of these characteristics were found. PMID:19820082

Microbial electrolysis cell accelerates phosphate remobilisation from iron phosphate contained in sewage sludge.

PubMed

Fischer, Fabian; Zufferey, Géraldine; Sugnaux, Marc; Happe, Manuel

2015-01-01

Phosphate was remobilised from iron phosphate contained in digested sewage sludge using a bio-electric cell. A significant acceleration above former results was caused by strongly basic catholytes. For these experiments a dual chambered microbial electrolysis cell with a small cathode (40 mL) and an 80 times larger anode (2.5 L) was equipped with a platinum sputtered reticulated vitreous carbon cathode. Various applied voltages (0.2-6.0 V) generated moderate to strongly basic catholytes using artificial waste water with pH close to neutral. Phosphate from iron phosphate contained in digested sewage sludge was remobilised most effectively at pH ∼13 with up to 95% yield. Beside minor electrochemical reduction, hydroxyl substitution was the dominating remobilisation mechanism. Particle-fluid kinetics using the "shrinking core" model allowed us to determine the reaction controlling step. Reaction rates changed with temperature (15-40 °C) and an activation energy of Ea = 55 kJ mol(-1) was found. These analyses indicated chemical and physical reaction control, which is of interest for future scale-up work. Phosphate remobilisation rates increased significantly, yields doubled and recovered PO4(3-) concentrations increased four times using a task specific bio-electric system. The result is a sustainable process for decentralized phosphate mining and a green chemical base generator useful also for many other sustainable processing needs.

21 CFR 184.1296 - Ferric ammonium citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... citrate (iron (III) ammonium citrate) is prepared by the reaction of ferric hydroxide with citric acid... 18.5 percent iron, approximately 9 percent ammonia, and 65 percent citric acid and occurs as reddish... composed of 14.5 to 16 percent iron, approximately 7.5 percent ammonia, and 75 percent citric acid and...

21 CFR 184.1296 - Ferric ammonium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... citrate (iron (III) ammonium citrate) is prepared by the reaction of ferric hydroxide with citric acid... 18.5 percent iron, approximately 9 percent ammonia, and 65 percent citric acid and occurs as reddish... composed of 14.5 to 16 percent iron, approximately 7.5 percent ammonia, and 75 percent citric acid and...

21 CFR 184.1296 - Ferric ammonium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... citrate (iron (III) ammonium citrate) is prepared by the reaction of ferric hydroxide with citric acid... 18.5 percent iron, approximately 9 percent ammonia, and 65 percent citric acid and occurs as reddish... composed of 14.5 to 16 percent iron, approximately 7.5 percent ammonia, and 75 percent citric acid and...

21 CFR 184.1296 - Ferric ammonium citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... citrate (iron (III) ammonium citrate) is prepared by the reaction of ferric hydroxide with citric acid... 18.5 percent iron, approximately 9 percent ammonia, and 65 percent citric acid and occurs as reddish... composed of 14.5 to 16 percent iron, approximately 7.5 percent ammonia, and 75 percent citric acid and...

5  W output power from a double-clad hybrid fiber with Yb-doped phosphate core and silicate cladding.

PubMed

Wang, Longfei; He, Dongbing; Zhang, Lei; Yu, Chunlei; Feng, Suya; Wang, Meng; Chen, Danping; Hu, Lili

2017-08-01

For the first time, to the best of our knowledge, we report on the realization of a laser from a Yb-doped phosphate core/silicate cladding double-clad hybrid fiber. 5 W output power was extracted with 14.6% slope efficiency and a laser spectrum of a 1027 nm central wavelength from a 20 cm long single-mode fiber with a ∼10  μm core diameter in a 20%-4% laser cavity. The laser efficiency can be significantly enhanced by correspondingly adjusting and optimizing the laser oscillator.

Crystal Structures of An F420-Dependent Glucose-6-Phosphate Dehydrogenase Fgd1 Involved in the Activation of the Anti-Tb Drug Candidate Pa-824 Reveal the Basis of Coenzyme And Substrate Binding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bashiri, G.; Squire, C.J.; Moreland, N.J.

2009-05-11

The modified flavin coenzyme F{sub 420} is found in a restricted number of microorganisms. It is widely distributed in mycobacteria, however, where it is important in energy metabolism, and in Mycobacterium tuberculosis (Mtb) is implicated in redox processes related to non-replicating persistence. In Mtb, the F{sub 420}-dependent glucose-6-phosphate dehydrogenase FGD1 provides reduced F{sub 420} for the in vivo activation of the nitroimidazopyran prodrug PA-824, currently being developed for anti-tuberculosis therapy against both replicating and persistent bacteria. The structure of M. tuberculosis FGD1 has been determined by x-ray crystallography both in its apo state and in complex with F{sub 420} andmore » citrate at resolutions of 1.90 and 1.95{angstrom}, respectively. The structure reveals a highly specific F{sub 420} binding mode, which is shared with several other F{sub 420}-dependent enzymes. Citrate occupies the substrate binding pocket adjacent to F{sub 420} and is shown to be a competitive inhibitor (IC{sub 50} 43 {micro}m). Modeling of the binding of the glucose 6-phosphate (G6P) substrate identifies a positively charged phosphate binding pocket and shows that G6P, like citrate, packs against the isoalloxazine moiety of F{sub 420} and helps promote a butterfly bend conformation that facilitates F{sub 420} reduction and catalysis.« less

Addition of senna improves quality of colonoscopy preparation with magnesium citrate.

PubMed

Vradelis, Stergios; Kalaitzakis, Evangelos; Sharifi, Yalda; Buchel, Otto; Keshav, Satish; Chapman, Roger W; Braden, Barbara

2009-04-14

To prospectively investigate the effectiveness and patient's tolerance of two low-cost bowel cleansing preparation protocols based on magnesium citrate only or the combination of magnesium citrate and senna. A total of 342 patients who were referred for colonoscopy underwent a colon cleansing protocol with magnesium citrate alone (n = 160) or magnesium citrate and senna granules (n = 182). The colonoscopist rated the overall efficacy of colon cleansing using an established score on a 4-point scale. Patients were questioned before undergoing colonoscopy for side effects and symptoms during bowel preparation. The percentage of procedures rescheduled because of insufficient colon cleansing was 7% in the magnesium citrate group and 4% in the magnesium citrate/senna group (P = 0.44). Adequate visualization of the colonic mucosa was rated superior under the citramag/senna regimen (P = 0.004). Both regimens were well tolerated, and did not significantly differ in the occurrence of nausea, bloating or headache. However, abdominal cramps were observed more often under the senna protocol (29.2%) compared to the magnesium citrate only protocol (9.9%, P < 0.0003). The addition of senna to the bowel preparation protocol with magnesium citrate significantly improves the cleansing outcome.

Modeling and simulation of sexual activity daily diary data of patients with female sexual arousal disorder treated with sildenafil citrate (Viagra).

PubMed

Claret, Laurent; Cox, Eugene H; McFadyen, Lynn; Pidgen, Alwyn; Johnson, Patrick J; Haughie, Scott; Boolell, Mitra; Bruno, Rene

2006-08-01

To develop a model to explore the dose-response of sildenafil citrate in patients with female sexual arousal disorder (FSAD) based on telephone sexual activity daily diary (TSADD) data obtained in double-blind, placebo controlled clinical studies. Data were available on 614 patients with FSAD. A parametric model (Weibull distribution) was developed to describe the probability density function of the time between sexual events. Orgasm satisfaction scores and overall sexual satisfaction scores were simultaneously modeled as ordered categorical variables. Simulations were performed to evaluate the expected clinical response in patients with FSAD. The expected time between sexual events was approximately 3.5 days. Satisfaction scores increased with time to achieve a plateau after 3 to 4 weeks on treatment. The expected probability of satisfying orgasm (score of 3 and higher) ranged from 34.7% for placebo to 41.6% for 100 mg sildenafil citrate. Treatment effect (difference from placebo) was 6.9% for 100 mg sildenafil citrate, ranging from 0.6 to 24.7% for testosterone levels of 0.1 to 4.0 pg/ml. The treatment effect in postmenopausal women was larger than in premenopausal women. A modeling and simulation framework to support drug development in FSAD was developed. Sildenafil citrate demonstrated a dose-dependent effect in patients with FSAD.

Structural Basis for Norovirus Inhibition and Fucose Mimicry by Citrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hansman, Grant S.; Shahzad-ul-Hussan, Syed; McLellan, Jason S.

2012-01-20

Human noroviruses bind with their capsid-protruding domains to histo-blood-group antigens (HBGAs), an interaction thought to direct their entry into cells. Although human noroviruses are the major cause of gastroenteritis outbreaks, development of antivirals has been lacking, mainly because human noroviruses cannot be cultivated. Here we use X-ray crystallography and saturation transfer difference nuclear magnetic resonance (STD NMR) to analyze the interaction of citrate with genogroup II (GII) noroviruses. Crystals of citrate in complex with the protruding domain from norovirus GII.10 Vietnam026 diffracted to 1.4 {angstrom} and showed a single citrate bound at the site of HBGA interaction. The citrate interactionmore » was coordinated with a set of capsid interactions almost identical to that involved in recognizing the terminal HBGA fucose, the saccharide which forms the primary conserved interaction between HBGAs and GII noroviruses. Citrate and a water molecule formed a ring-like structure that mimicked the pyranoside ring of fucose. STD NMR showed the protruding domain to have weak affinity for citrate (460 {mu}M). This affinity, however, was similar to the affinities of the protruding domain for fucose (460 {mu}M) and H type 2 trisaccharide (390 {mu}M), an HBGA shown previously to be specifically recognized by human noroviruses. Importantly, competition STD NMR showed that citrate could compete with HBGA for norovirus binding. Together, the results suggest that citrate and other glycomimetics have the potential to block human noroviruses from binding to HBGAs.« less

Soluble phosphate fertilizer production using acid effluent from metallurgical industry.

PubMed

Mattiello, Edson M; Resende Filho, Itamar D P; Barreto, Matheus S; Soares, Aline R; Silva, Ivo R da; Vergütz, Leonardus; Melo, Leônidas C A; Soares, Emanuelle M B

2016-01-15

Preventive and effective waste management requires cleaner production strategies and technologies for recycling and reuse. Metallurgical industries produce a great amount of acid effluent that must be discarded in a responsible manner, protecting the environment. The focus of this study was to examine the use of this effluent to increase reactivity of some phosphate rocks, thus enabling soluble phosphate fertilizer production. The effluent was diluted in deionized water with the following concentrations 0; 12.5; 25; 50; 75% (v v(-1)), which were added to four natural phosphate rocks: Araxá, Patos, Bayovar and Catalão and then left to react for 1 h and 24 h. There was an increase in water (PW), neutral ammonium citrate (PNAC) and citric acid (PCA) soluble phosphorus fractions. Such increases were dependent of rock type while the reaction time had no significant effect (p < 0.05) on the chemical and mineralogical phosphate characteristics. Phosphate fertilizers with low toxic metal concentrations and a high level of micronutrients were produced compared to the original natural rocks. The minimum amount of total P2O5, PNAC and PW, required for national legislation for phosphate partially acidulated fertilizer, were met when using Catalão and the effluent at the concentration of 55% (v v(-1)). Fertilizer similar to partially acidulated phosphate was obtained when Bayovar with effluent at 37.5% (v v(-1)) was used. Even though fertilizers obtained from Araxá and Patos did not contain the minimum levels of total P2O5 required by legislation, they can be used as a nutrient source and for acid effluent recycling and reuse. Copyright © 2015 Elsevier Ltd. All rights reserved.

Addition of senna improves quality of colonoscopy preparation with magnesium citrate

PubMed Central

Vradelis, Stergios; Kalaitzakis, Evangelos; Sharifi, Yalda; Buchel, Otto; Keshav, Satish; Chapman, Roger W; Braden, Barbara

2009-01-01

AIM: To prospectively investigate the effectiveness and patient’s tolerance of two low-cost bowel cleansing preparation protocols based on magnesium citrate only or the combination of magnesium citrate and senna. METHODS: A total of 342 patients who were referred for colonoscopy underwent a colon cleansing protocol with magnesium citrate alone (n = 160) or magnesium citrate and senna granules (n = 182). The colonoscopist rated the overall efficacy of colon cleansing using an established score on a 4-point scale. Patients were questioned before undergoing colonoscopy for side effects and symptoms during bowel preparation. RESULTS: The percentage of procedures rescheduled because of insufficient colon cleansing was 7% in the magnesium citrate group and 4% in the magnesium citrate/senna group (P = 0.44). Adequate visualization of the colonic mucosa was rated superior under the citramag/senna regimen (P = 0.004). Both regimens were well tolerated, and did not significantly differ in the occurrence of nausea, bloating or headache. However, abdominal cramps were observed more often under the senna protocol (29.2%) compared to the magnesium citrate only protocol (9.9%, P < 0.0003). CONCLUSION: The addition of senna to the bowel preparation protocol with magnesium citrate significantly improves the cleansing outcome. PMID:19360920

Sodium citrate inhibits the proliferation of human gastric adenocarcinoma epithelia cells

PubMed Central

Xia, Yuan; Zhang, Xulong; Bo, Agula; Sun, Juan; Li, Minhui

2018-01-01

The objective of the present study was to investigate the cytotoxic effects of sodium citrate on human gastric adenocarcinoma epithelia AGS cells. Numerous cytotoxicity-associated sodium citrate-induced effects were assessed, including cell viability and proliferation, cytokine expression and caspase activity. In vitro studies demonstrated that incubation with sodium citrate (>3.125 mM) inhibited AGS cell viability and proliferation in a dose-dependent manner. Incubation with sodium citrate for 24 h revealed that the levels of interleukin-1β (IL-1β), IL-8 and tumor necrosis factor increased with an increasing of dose of sodium citrate, whereas the IL-6 levels exhibited only a slight alteration. In addition, increases in caspase-3 and −9 activities were associated with increased duration of treatment and dosage of sodium citrate. Collectively, the results of the present study demonstrated that treatment with sodium citrate at higher concentrations or for longer durations exerts a cytotoxic effect on AGS cells via the induction of the intrinsic apoptosis pathway and the alteration in the levels of certain cytokines. PMID:29616124

Sildenafil citrate, bronchopulmonary dysplasia and disordered pulmonary gas exchange: any benefits?

PubMed

Nyp, M; Sandritter, T; Poppinga, N; Simon, C; Truog, W E

2012-01-01

The objective of this study is to determine the effects that sildenafil citrate has on gas exchange in infants with bronchopulmonary dysplasia (BPD)-associated pulmonary hypertension (PH). A retrospective review was performed from 2005 to 2009. Infants treated with sildenafil citrate for greater than 48  h were included. Standard patient data was collected, including echocardiogram, inspired oxygen and systemic blood pressure, before and during administration of sildenafil citrate. Sildenafil citrate was used in 21 preterm infants with BPD-associated PH. A significant reduction in estimated right ventricular peak systolic pressure was seen after initiation of sildenafil citrate, with the majority of infants showing no improvement in gas exchange at 48  h of treatment. Four infants died during treatment. Sildenafil citrate reduced estimated pulmonary artery pressures, but this reduction was not reflected in improved gas exchange within the first 48  h.

Persistent 3'-phosphate termini and increased cytotoxicity of radiomimetic DNA double-strand breaks in cells lacking polynucleotide kinase/phosphatase despite presence of an alternative 3'-phosphatase.

PubMed

Chalasani, Sri Lakshmi; Kawale, Ajinkya S; Akopiants, Konstantin; Yu, Yaping; Fanta, Mesfin; Weinfeld, Michael; Povirk, Lawrence F

2018-05-25

Polynucleotide kinase/phosphatase (PNKP) has been implicated in non-homologous end joining (NHEJ) of DNA double-strand breaks (DSBs). To assess the consequences of PNKP deficiency for NHEJ of 3'-phosphate-ended DSBs, PNKP-deficient derivatives of HCT116 and of HeLa cells were generated using CRISPR/CAS9. For both cell lines, PNKP deficiency conferred sensitivity to ionizing radiation as well as to neocarzinostatin (NCS), which specifically induces DSBs bearing protruding 3'-phosphate termini. Moreover, NCS-induced DSBs, detected as 53BP1 foci, were more persistent in PNKP -/- HCT116 cells compared to their wild-type (WT) counterparts. Surprisingly, PNKP-deficient whole-cell and nuclear extracts were biochemically competent in removing both protruding and recessed 3'-phosphates from synthetic DSB substrates, albeit much less efficiently than WT extracts, suggesting an alternative 3'-phosphatase. Measurements by ligation-mediated PCR showed that PNKP-deficient HeLa cells contained significantly more 3'-phosphate-terminated and fewer 3'-hydroxyl-terminated DSBs than parental cells 5-15 min after NCS treatment, but this difference disappeared by 1 h. These results suggest that, despite presence of an alternative 3'-phosphatase, loss of PNKP significantly sensitizes cells to 3'-phosphate-terminated DSBs, due to a 3'-dephosphorylation defect. Copyright © 2018 Elsevier B.V. All rights reserved.

Overexpression, crystallization and preliminary X-ray crystallographic analysis of erythronate-4-phosphate dehydrogenase from Pseudomonas aeruginosa.

PubMed

Ha, Jun Yong; Lee, Ji Hyun; Kim, Kyoung Hoon; Kim, Do Jin; Lee, Hyung Ho; Kim, Hye-Kyung; Yoon, Hye-Jin; Suh, Se Won

2006-02-01

The enzyme erythronate-4-phosphate dehydrogenase catalyses the conversion of erythronate-4-phosphate to 3-hydroxy-4-phospho-hydroxy-alpha-ketobutyrate. It belongs to the D-isomer-specific 2-hydroxyacid dehydrogenase family. It is essential for de novo biosynthesis of vitamin B6 (pyridoxine). Erythronate-4-phosphate dehydrogenase from Pseudomonas aeruginosa, a homodimeric enzyme consisting of two identical 380-residue subunits, has been overexpressed in Escherichia coli with a C-terminal purification tag and crystallized at 297 K using 0.7 M ammonium dihydrogen phosphate, 0.4 M ammonium tartrate, 0.1 M sodium citrate pH 5.6 and 10 mM cupric chloride. X-ray diffraction data were collected to 2.20 A from a crystal grown in the presence of NADH. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 84.77, b = 101.28, c = 142.58 A. A dimeric molecule is present in the asymmetric unit, giving a crystal volume per protein weight (VM) of 3.64 A3 Da(-1) and a solvent content of 66%.

Modification by food of the calcium absorbability and physicochemical effects of calcium citrate

NASA Technical Reports Server (NTRS)

Wabner, C. L.; Pak, C. Y.

1992-01-01

The food-calcium (Ca) interaction was examined in 12 healthy women (mean age 38 years) maintained on a constant metabolic diet. They underwent three phases of study, comprised of control (no Ca), Ca citrate (1 g Ca/day) during meals, and Ca citrate separately from meals. Each phase was 7 days in length and two 24-hour urine samples were collected on days 6 and 7. The rise from the control phase in urinary Ca was slightly more prominent when Ca citrate was given with meals than without (68 and 62%, respectively). The fall in urinary phosphorus was equivalent at about 25% between Ca citrate phases. The rise in urinary citrate and pH and the decline in urinary ammonium were more prominent when Ca citrate was given with meals; however, the changes were small or nonsignificant. The urinary saturation of Ca oxalate, brushite or monosodium urate did not differ between the two Ca citrate phases. There was a nonsignificant rise in serum iron during Ca citrate phases. The results suggest that: 1) dissolution and absorption of Ca citrate might be slightly greater when given with food than without; 2) that the ability of Ca citrate to attenuate crystallization of stone-forming Ca salts in urine is not modified by food; and 3) that Ca citrate may not impair iron absorption from food.

Hydrous iron oxide modified diatomite as an active filtration medium for phosphate capture.

PubMed

Wang, Zhe; Lin, Yan; Wu, Deyi; Kong, Hainan

2016-02-01

A simple method to functionalize diatomite with hydrous iron oxide was attempted and its performance as a new active filtration material to remove and recover phosphate from water was investigated under varying solution conditions. The Langmuir phosphate adsorption capacity increased from 0.6 mgP/g for raw diatomite to 4.89, 14.71, 25.02 mgP/g for hydrous iron oxide modified diatomite (HIOMD), depending on the amount of iron loaded. Loading of hydrous iron oxide caused the increase in true and bulk density and a decline in filtration rate, but to a lesser extent. It was shown that the HIOMD product with suitable iron content could retain a good filtration performance with a greatly increased adsorption capacity for phosphate. The phosphate adsorption increased by decreasing pH and by increasing ionic strength at high pH levels. The adsorption process was interpreted by ligand exchange. Coexisting oxyanions of sulfate, nitrate, citrate, carbonate, silicate and humic acid showed different effects on phosphate fixation but it was presumed that their influence at their concentrations and pH levels commonly encountered in effluent or natural waters was limited, i.e., HIOMD had a reasonably good selectivity. Results in repeated adsorption, desorption and regeneration experiment showed that the adsorbed phosphate could be recovered and the material could be reused after regeneration. The column test showed that HIOMD could be potentially utilized as an adsorption filtration medium for phosphate removal and recovery from water. Copyright © 2015 Elsevier Ltd. All rights reserved.

Are All Gallium Citrate Preparations the Same? 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waxman, Alan D.; Kawada, Tom; Wolf, Walter

1975-12-01

Recent studies on brain imaging using 67Ga citrate from three different manufacturers revealed some clinical differences. Using chromatographic techniques, it was found that 67Ga citrate supplied by vendor A clearly differed from those of vendors B and C in mobility. When citrate was added to material of vendor B to bring the final concentration to 25 mg/ml, the chromatographic mobility increased dramatically. Addition of benzyl alcohol had no effect. The mechanisms involved in causing these chromatographic changes are not clear; however, the in vitro variations noted indicate a difference in chemistry which may ultimately affect the distribution andmore » localization of the radiopharmaceutical.« less

Pathogenic mutations of the human mitochondrial citrate carrier SLC25A1 lead to impaired citrate export required for lipid, dolichol, ubiquinone and sterol synthesis.

PubMed

Majd, Homa; King, Martin S; Smith, Anthony C; Kunji, Edmund R S

2018-01-01

Missense mutations of the human mitochondrial citrate carrier, encoded by the SLC25A1 gene, lead to an autosomal recessive neurometabolic disorder characterised by neonatal-onset encephalopathy with severe muscular weakness, intractable seizures, respiratory distress, and lack of psychomotor development, often resulting in early death. Here, we have measured the effect of all twelve known pathogenic mutations on the transport activity. The results show that nine mutations abolish transport of citrate completely, whereas the other three reduce the transport rate by >70%, indicating that impaired citrate transport is the most likely primary cause of the disease. Some mutations may be detrimental to the structure of the carrier, whereas others may impair key functional elements, such as the substrate binding site and the salt bridge network on the matrix side of the carrier. To understand the consequences of impaired citrate transport on metabolism, the substrate specificity was also determined, showing that the human citrate carrier predominantly transports citrate, isocitrate, cis-aconitate, phosphoenolpyruvate and malate. Although D-2- and L-2 hydroxyglutaric aciduria is a metabolic hallmark of the disease, it is unlikely that the citrate carrier plays a significant role in the removal of hydroxyglutarate from the cytosol for oxidation to oxoglutarate in the mitochondrial matrix. In contrast, computer simulations of central metabolism predict that the export of citrate from the mitochondrion cannot be fully compensated by other pathways, restricting the cytosolic production of acetyl-CoA that is required for the synthesis of lipids, sterols, dolichols and ubiquinone, which in turn explains the severe disease phenotypes. Copyright © 2017. Published by Elsevier B.V.

Basolateral phosphate transport in renal proximal-tubule-like OK cells.

PubMed

Barac-Nieto, M; Alfred, M; Spitzer, A

2002-09-01

It is generally assumed that phosphate (Pi) effluxes from proximal tubule cells by passive diffusion across the basolateral (BL) membrane. We explored the mechanism of BL Pi efflux in proximal tubule-like OK cells grown on permeable filters and then loaded with 32P. BL efflux of 32P was significantly stimulated (P < 0.05) by exposing the BL side of the monolayer to 12.5 mM Pi, to 10 mM citrate, or by acid-loading the cells, and was inhibited by exposure to 0.05 mM Pi or 25 mM HCO3; by contrast, BL exposure to high (8.4) pH, 40 mM K+, 140 mM Na gluconate (replacing NaCl), 10 mM lactate, 10 mM succinate, or 10 mM glutamate did not affect BL 32P efflux. These data are consistent with BL Pi efflux from proximal tubule-like cells occurring, in part, via an electro-neutral sodium-sensitive anion transporter capable of exchanging two moles of intracellular acidic H2PO4- for each mole of extracellular basic HPO4= or for citrate.

Synthesis of Stable Citrate-Capped Silver Nanoprisms.

PubMed

Haber, Jason; Sokolov, Konstantin

2017-10-10

Citrate-stabilized silver nanoprisms (AgNPrs) can be easily functionalized using well-developed thiol based surface chemistry that is an important requirement for biosensor applications utilizing localized surface plasmon resonance (LSPR) and surface-enhanced Raman Scattering (SERS). Unfortunately, currently available protocols for synthesis of citrate-coated AgNPrs do not produce stable nanoparticles thus limiting their usefulness in biosensing applications. Here we address this problem by carrying out a systematic study of citrate-stabilized, peroxide-based synthesis of AgNPrs to optimize reaction conditions for production of stable and reproducible nanoprisms. Our analysis showed that concentration of secondary reducing agent, l-ascorbic acid, is critical to AgNPr stability. Furthermore, we demonstrated that optimization of other synthesis conditions such as stabilizer concentration, rate of silver nitrate addition, and seed dilution result in highly stable nanoprisms with narrow absorbance peaks ranging from 450 nm into near-IR. In addition, the optimized reaction conditions can be used to produce AgNPrs in a one-pot synthesis instead of a previously described two-step reaction. The resulting nanoprisms can readily interact with thiols for easy surface functionalization. These studies provide an optimized set of parameters for precise control of citrate stabilized AgNPr synthesis for biomedical applications.

Dietary and genetic evidence for phosphate toxicity accelerating mammalian aging

PubMed Central

Ohnishi, Mutsuko; Razzaque, M. Shawkat

2010-01-01

Identifying factors that accelerate the aging process can provide important therapeutic targets for slowing down this process. Misregulation of phosphate homeostasis has been noted in various skeletal, cardiac, and renal diseases, but the exact role of phosphate toxicity in mammalian aging is not clearly defined. Phosphate is widely distributed in the body and is involved in cell signaling, energy metabolism, nucleic acid synthesis, and the maintenance of acid-base balance by urinary buffering. In this study, we used an in vivo genetic approach to determine the role of phosphate toxicity in mammalian aging. Klotho-knockout mice (klotho−/−) have a short life span and show numerous physical, biochemical, and morphological features consistent with premature aging, including kyphosis, uncoordinated movement, hypogonadism, infertility, severe skeletal muscle wasting, emphysema, and osteopenia, as well as generalized atrophy of the skin, intestine, thymus, and spleen. Molecular and biochemical analyses suggest that increased renal activity of sodium-phosphate cotransporters (NaPi2a) leads to severe hyperphosphatemia in klotho−/− mice. Genetically reducing serum phosphate levels in klotho−/− mice by generating a NaPi2a and klotho double-knockout (NaPi2a−/−/klotho−/−) strain resulted in amelioration of premature aging-like features. The NaPi2a−/−/klotho−/− double-knockout mice regained reproductive ability, recovered their body weight, reduced their organ atrophy, and suppressed ectopic calcifications, with the resulting effect being prolonged survival. More important, when hyperphosphatemia was induced in NaPi2a−/−/klotho−/− mice by feeding with a high-phosphate diet, premature aging-like features reappeared, clearly suggesting that phosphate toxicity is the main cause of premature aging in klotho−/− mice. The results of our dietary and genetic manipulation studies provide in vivo evidence for phosphate toxicity accelerating the

21 CFR 520.622a - Diethylcarbamazine citrate tablets.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Diethylcarbamazine citrate tablets. 520.622a... Diethylcarbamazine citrate tablets. (a) Sponsors. (1) See 015579 in § 510.600(c) of this chapter for use of 50, 200, and 400 milligram tablets for prevention of heartworm disease in dogs and as an aid in the treatment...

Risks and benefits of citrate anticoagulation for continuous renal replacement therapy.

PubMed

Shum, H P; Yan, W W; Chan, T M

2015-04-01

Heparin, despite its significant side-effects, is the most commonly used anticoagulant for continuous renal replacement therapy in critical care setting. In recent years, citrate has gained much popularity by improving continuous renal replacement therapy circuit survival and decreasing blood transfusion requirements. However, its complex metabolic consequences warrant modification in the design of the citrate-based continuous renal replacement therapy protocol. With thorough understanding of the therapeutic mechanism of citrate, a simple and practicable protocol can be devised. Citrate-based continuous renal replacement therapy can be safely and widely used in the clinical setting with appropriate clinical staff training.

Sildenafil citrate in the treatment of pain in primary dysmenorrhea: a randomized controlled trial†

PubMed Central

Dmitrovic, R.; Kunselman, A.R.; Legro, R. S.

2013-01-01

STUDY QUESTION Is a vaginal preparation of sildenafil citrate capable of alleviating acute menstrual pain in patients with primary dysmenorrhea (PD)? SUMMARY ANSWER A vaginal preparation of sildenafil citrate is capable of alleviating acute menstrual pain in patients with PD with no observed adverse effects. WHAT IS KNOWN ALREADY Oral preparations of nitric oxide (NO) donor drugs augment relaxant effects of NO on myometrial cells, reverse the vasoconstriction caused by prostaglandins and successfully alleviate pain, but the incidence of side effects is too high for routine clinical use. Sildenafil citrate inhibits type 5-specific phosphodiesterase (PDE5), thus preventing the degradation of cyclic guanosine monophosphate (cGMP) in the muscle and augmenting the vasodilatory effects of NO. Therefore, by inhibiting PDE5, the tissue remains relaxed and more blood can circulate through. It has been used previously in a vaginal form with no observed side effects, and it enhances endometrial blood flow. STUDY DESIGN, SIZE, DURATION A double-blind, randomized, controlled trial comparing vaginal preparation of sildenafil citrate (100 mg single dose) to a placebo in 62 PD patients at the time of painful menstruation was conducted. The primary outcome was total pain relief over 4 consecutive hours (TOPAR4) comparing sildenafil citrate to placebo, where higher TOPAR4 scores represent better pain relief. Secondary outcomes were pain relief as measured by the visual analog scale (VAS) and uterine artery pulsatility index (PI). Subjects were recruited from December 2007 to January 2011. The trial was stopped due to closeout of the funding for the study. PARTICIPANTS, SETTINGS, METHODS Participants were women in good health, were aged 18–35 years and suffered from moderate to severe PD. They were randomized to either vaginal placebo or 100 mg vaginal sildenafil citrate in a 1:1 ratio using random permuted blocks having a block size of 4. At baseline and 1, 2, 3, and 4 h post

Sildenafil citrate in the treatment of pain in primary dysmenorrhea: a randomized controlled trial.

PubMed

Dmitrovic, R; Kunselman, A R; Legro, R S

2013-11-01

Is a vaginal preparation of sildenafil citrate capable of alleviating acute menstrual pain in patients with primary dysmenorrhea (PD)? A vaginal preparation of sildenafil citrate is capable of alleviating acute menstrual pain in patients with PD with no observed adverse effects. Oral preparations of nitric oxide (NO) donor drugs augment relaxant effects of NO on myometrial cells, reverse the vasoconstriction caused by prostaglandins and successfully alleviate pain, but the incidence of side effects is too high for routine clinical use. Sildenafil citrate inhibits type 5-specific phosphodiesterase (PDE5), thus preventing the degradation of cyclic guanosine monophosphate (cGMP) in the muscle and augmenting the vasodilatory effects of NO. Therefore, by inhibiting PDE5, the tissue remains relaxed and more blood can circulate through. It has been used previously in a vaginal form with no observed side effects, and it enhances endometrial blood flow. A double-blind, randomized, controlled trial comparing vaginal preparation of sildenafil citrate (100 mg single dose) to a placebo in 62 PD patients at the time of painful menstruation was conducted. The primary outcome was total pain relief over 4 consecutive hours (TOPAR4) comparing sildenafil citrate to placebo, where higher TOPAR4 scores represent better pain relief. Secondary outcomes were pain relief as measured by the visual analog scale (VAS) and uterine artery pulsatility index (PI). Subjects were recruited from December 2007 to January 2011. The trial was stopped due to closeout of the funding for the study. Participants were women in good health, were aged 18-35 years and suffered from moderate to severe PD. They were randomized to either vaginal placebo or 100 mg vaginal sildenafil citrate in a 1:1 ratio using random permuted blocks having a block size of 4. At baseline and 1, 2, 3, and 4 h post-treatment, patients were asked to provide assessment of their degree of pain using two scales: (i) pain on the 5-level

21 CFR 520.623 - Diethylcarbamazine citrate, oxibendazole chewable tablets.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Diethylcarbamazine citrate, oxibendazole chewable tablets. 520.623 Section 520.623 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... § 520.623 Diethylcarbamazine citrate, oxibendazole chewable tablets. (a) Specifications. Each tablet...

Preparation and Quality Control of 68Ga-Citrate for PET Applications

PubMed Central

Aghanejad, Ayuob; Jalilian, Amir Reza; Ardaneh, Khosro; Bolourinovin, Fatemeh; Yousefnia, Hassan; Samani, Ali Bahrami

2015-01-01

Objective(s): In nuclear medicine studies, gallium-68 (8Ga) citrate has been recently known as a suitable infection agent in positron emission tomography (PET). In this study, by applying an in-house produced 68Ge/68Ga generator, a simple technique for the synthesis and quality control of 68Ga-citrate was introduced; followed by preliminary animal studies. Methods: 68GaCl3 eluted from the generator was studied in terms of quality control factors including radiochemical purity (assessed by HPLC and RTLC), chemical purity (assessed by ICP-EOS), radionuclide purity (evaluated by HPGe), and breakthrough. 68Ga-citrate was prepared from eluted 68GaCl3 and sodium citrate under various reaction conditions. Stability of the complex was evaluated in human serum for 2 h at 370C, followed by biodistribution studies in rats for 120 min. Results: 68Ga-citrate was prepared with acceptable radiochemical purity (>97 ITLC and >98% HPLC), specific activity (4-6 GBq/mM), chemical purity (Sn, Fe<0.3 ppm and Zn<0.2 ppm) within 15 min at 500C. The biodistribution of 68Ga-citrate was consistent with former reports up to 120 minutes. Conclusion: This study demonstrated the possible in-house preparation and quality control of 68Ga-citrate, using a commercially available 68Ge/68Ga generator for PET imaging throughout the country. PMID:27408889

Biowaiver or Bioequivalence: Ambiguity in Sildenafil Citrate BCS Classification.

PubMed

Miranda, Claudia; Pérez-Rodríguez, Zenia; Hernández-Armengol, Rosario; Quiñones-García, Yaidel; Betancourt-Purón, Tania; Cabrera-Pérez, Miguel Ángel

2018-05-01

The aim of the present study is to contribute to the scientific characterization of sildenafil citrate according to the Biopharmaceutics Classification System, following the World Health Organization (WHO) guidelines for biowaivers. The solubility and intestinal permeability data of sildenafil citrate were collected from literature; however, the experimental solubility studies are inconclusive and its "high permeability" suggests an API in the borderline of BCS Class I and Class II. The pH-solubility profile was determined using the saturation shake-flask method over the pH range of 1.2-6.8 at a temperature of 37 °C in aqueous media. The intestinal permeability was determined in rat by a closed-loop in situ perfusion method (the Doluisio technique). The solubility of sildenafil citrate is pH-dependent and at pH 6.8 the dose/solubility ratio obtained does not meet the WHO criteria for "high solubility." The high permeability values obtained by in situ intestinal perfusion in rat reinforce the published permeability data for sildenafil citrate. The experimental results obtained and the data available in the literature suggest that sildenafil citrate is clearly a Class II of BCS, according to the current biopharmaceutics classification system and WHO guidance.

Sildenafil citrate (Viagra) enhances vasodilatation in fetal growth restriction.

PubMed

Wareing, Mark; Myers, Jenny E; O'Hara, Maureen; Baker, Philip N

2005-05-01

Fetal growth restriction (FGR) affects up to 8% of all pregnancies and has massive short-term (increased fetal morbidity and mortality) and long-term (increased incidence of cardiovascular disease in adulthood) health implications. Doppler waveform analysis of pregnancies complicated by FGR suggests compromised uteroplacental circulation and placental hypoperfusion. Our aim was to determine whether myometrial small artery function was aberrant in FGR and to assess whether sildenafil citrate could improve vasodilatation in FGR pregnancies. Small arteries dissected from myometrial biopsies obtained at cesarean section from normal pregnant women (n = 27) or women whose pregnancies were complicated by FGR (n = 12) were mounted on wire myographs. Vessels were constricted (with arginine vasopressin or U46619) and relaxed (with bradykinin) before and after incubation with a phosphodiesterase-5 inhibitor, sildenafil citrate. We demonstrated increased myometrial small artery vasoconstriction and decreased endothelium-dependent vasodilatation in vessels from women whose pregnancies were complicated by FGR. Sildenafil citrate significantly reduced vasoconstriction and significantly improved relaxation of FGR small arteries. We conclude that sildenafil citrate improves endothelial function of myometrial vessels from women whose pregnancies are complicated by intrauterine growth restriction. Sildenafil citrate may offer a potential therapeutic strategy to improve uteroplacental blood flow in FGR pregnancies.

Feasibility of a novel low-volume and sodium phosphate-free bowel preparation regimen for colon capsule endoscopy.

PubMed

Zhou, Jieqiong; Tang, Xiaowei; Wang, Jing; Chen, Zhenyu; Wang, Xinying; Jiang, Bo

2017-08-01

Bowel preparation regimens for colon capsule endoscopy are not yet standardized since they are not well optimized. The aim of the present study was to evaluate the feasibility of a novel low-volume and sodium phosphate-free bowel preparation regimen for colon capsule endoscopy. A total of 31 patients were prospectively enrolled. In the novel regimen, on the day prior to examination, a low-fiber diet was permitted, 5 mg mosapride citrate was administered twice (1 h prior to lunch and supper) and 1 l polyethylene glycol was administered in the evening. On the day of the examination, an additional 1 l polyethylene glycol, 5 mg mosapride citrate and 200 mg simethicone were administered before capsule ingestion. Polyethylene glycol booster (0.5 l) was administered twice, at 1 and 4 h following capsule ingestion. Colon cleansing levels, ileocecal valve transit time and completion rate were evaluated. A total of 29 patients were included in the final analysis, 90% of whom achieved adequate preparation of the overall colon. Ileocecal valve transit time was 2.35±0.82 h and completion rate was 79.3%. The results revealed that the novel low-volume and sodium phosphate-free bowel preparation regimen for colon capsule endoscopy was feasible, with adequate colon cleansing and completion rates, and has the potential to be used as an alternative regimen.

The Effect of Single, Binary and Ternary Anions of Chloride, Carbonate and Phosphate on the Release of 2,4-Dichlorophenoxyacetate Intercalated into the Zn-Al-layered Double Hydroxide Nanohybrid

NASA Astrophysics Data System (ADS)

Hussein, Mohd Zobir; Jaafar, Adila Mohamad; Yahaya, Asmah Hj.; Zainal, Zulkarnain

2009-11-01

Intercalation of beneficial anion into inorganic host has lead to an opportunity to synthesize various combinations of new organic-inorganic nanohybrids with various potential applications; especially, for the controlled release formulation and storage purposes. Investigation on the release behavior of 2,4-dichlorophenoxyacetate (2,4-D) intercalated into the interlayer of Zn-Al-layered double hydroxide (ZAN) have been carried out using single, binary and ternary aqueous systems of chloride, carbonate and phosphate. The release behavior of the active agent 2,4-D from its double-layered hydroxide nanohybrid ZANDI was found to be of controlled manner governed by pseudo-second order kinetics. It was found that carbonate medium yielded the highest accumulated release of 2,4-D, while phosphate in combination with carbonate and/or nitrate speeds up the release rate of 2,4-D. These results indicate that it is possible to design and develop new delivery system of latex stimulant compound with controlled release property based on 2,4-D that is known as a substance to increase latex production of rubber tree, Hevea brasiliensis.

Effects of citrate on hexavalent chromium reduction by structural Fe(II) in nontronite

DOE PAGES

Liu, Xiaolei; Dong, Hailiang; Yang, Xuewei; ...

2017-09-23

Previous studies have shown that organic ligands could influence Cr(VI) reduction by aqueous Fe 2+ and pyrite. In this study, the effects of citrate on Cr(VI) reduction by structural Fe(II) in nontronite (NAu-2) were investigated at pH 6. Our results showed that the presence of citrate decreased the rate but increased the amount of Cr(VI) reduction. The decreased rate was likely due to competitive sorption of citrate and anionic dichromate (Cr 2O 7–) to NAu-2 surface sites, because sorption of dichromate appeared to be the first step for subsequent Cr(VI) reduction. The increased amount of Cr(VI) reduction was likely becausemore » citrate served as an additional electron donor to reduce Cr(VI) through ligand-metal electron transfer in the presence of soluble Fe 3+, which was possibly derived from dissolution of reduced NAu-2. Soluble Cr(III)-citrate complex was a possible form of reduced Cr(VI) when citrate was present. Without citrate, nanometer-sized Cr 2O 3 particles were the product of Cr(VI) reduction. In conclusion, our study highlights the importance of citrate on Cr(VI) reduction and immobilization when iron-rich smectite is applied to treat Cr(VI) contaminant in organic carbon rich environments.« less

21 CFR 520.622c - Diethylcarbamazine citrate chewable tablets.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Diethylcarbamazine citrate chewable tablets. 520... Diethylcarbamazine citrate chewable tablets. (a) Specifications. Each chewable tablet contains 30, 45, 60, 120, 150... tablets as in paragraph (c)(2)(i) of this section. (2) For 000069, use of 60, 120, or 180 milligram...

Treatment of erectile dysfunction with sildenafil citrate in renal allograft recipients: a randomized, double-blind, placebo-controlled, crossover trial.

PubMed

Sharma, Raj K; Prasad, Narayan; Gupta, Amit; Kapoor, Rakesh

2006-07-01

Erectile dysfunction (ED) is observed frequently in patients with end-stage renal disease, hemodialysis patients, and renal allograft recipients. There are few studies of sildenafil use in renal allograft recipients. The study is designed as a randomized, double-blind, placebo-controlled, crossover trial. Efficacy was assessed by using the self-administered International Index of Erectile Function (IIEF), a 15-question validated measure of ED, and a global efficacy question (Did the treatment improve your erection?). Thirty-two eligible renal transplant recipients were included in this study. After treatment with sildenafil citrate, patients had significantly better scores in 13 of 15 questions, except for questions 11 (desire frequency; P = 0.39) and 12 (desire level; P = 0.61). Treatment efficacy assessed through questions 3 (penetration ability; P < 0.001) and 4 (maintenance frequency; P < 0.001) was significantly better after sildenafil therapy. There were no significant differences between baseline and post-placebo treatment scores, except for question 13 (relationship satisfaction). Patients treated with sildenafil had significantly better scores in 4 domains compared with baseline, but a difference was not observed in the sexual desire domain (P = 0.32). There were no significant differences in scores between placebo and baseline in any domain. On the global efficacy question, 81.3% of patients showed improvement compared with 18.7% with placebo. There were no differences in areas under the curve and maximum cyclosporine concentrations before and after sildenafil therapy. No patient discontinued the drug because of side effects except for 1 patient with visual hallucination. Treatment with sildenafil in renal transplant recipients is a valid option with an effective response.

Prospective, randomized comparison between raloxifene and clomiphene citrate for ovulation induction in polycystic ovary syndrome.

PubMed

de Paula Guedes Neto, Ernesto; Savaris, Ricardo Francalacci; von Eye Corleta, Helena; de Moraes, Gisele Silva; do Amaral Cristovam, Rafael; Lessey, Bruce A

2011-09-01

To compare the ovulation rate between raloxifene and clomiphene citrate (CC) in patients with polycystic ovary syndrome (PCOS). Double-blind, randomized, superiority clinical trial. Tertiary university hospital. Women with ovulatory dysfunction and PCOS based on the Rotterdam criteria. One of two oral treatments: 5 days of 100 mg/day of CC or R. Ovulation, based on follicle collapse on serial ultrasound and midsecretory serum progesterone concentration (≥3 ng/dL). The women with PCOS (n = 82) were randomized to receive CC (n = 40) or raloxifene (n = 42). From these, 68 patients finished the trial according to the protocol (CC: n = 37; raloxifene: n = 31). There were no statistically significant differences between the groups in ovulation rates per an intention-to-treat analysis based on ultrasound alone (CC: 21 of 40 vs. raloxifene: 17 of 42) or on progesterone levels (CC: 16 of 40 vs. raloxifene: 11 of 42). No serious adverse events were observed in either group. No statistically significant difference in ovulation was observed between raloxifene and clomiphene citrate in patients with PCOS with ovulatory dysfunction. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Diffuse abdominal gallium-67 citrate uptake in salmonella infections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garty, I.; Koren, A.

1987-11-01

Two pediatric patients with salmonella infections (one with typhoid fever and the second with salmonella C2 gastroenteritis), had a diffuse abdominal uptake of Ga-67 citrate. The possible explanation for this finding is discussed. Salmonella infection should be included as a cause in the differential diagnosis of diffuse accumulation of Ga-67 citrate.

Comparative genomics and transcriptome analysis of Aspergillus niger and metabolic engineering for citrate production

PubMed Central

Yin, Xian; Shin, Hyun-dong; Li, Jianghua; Du, Guocheng; Liu, Long; Chen, Jian

2017-01-01

Despite a long and successful history of citrate production in Aspergillus niger, the molecular mechanism of citrate accumulation is only partially understood. In this study, we used comparative genomics and transcriptome analysis of citrate-producing strains—namely, A. niger H915-1 (citrate titer: 157 g L−1), A1 (117 g L−1), and L2 (76 g L−1)—to gain a genome-wide view of the mechanism of citrate accumulation. Compared with A. niger A1 and L2, A. niger H915-1 contained 92 mutated genes, including a succinate-semialdehyde dehydrogenase in the γ-aminobutyric acid shunt pathway and an aconitase family protein involved in citrate synthesis. Furthermore, transcriptome analysis of A. niger H915-1 revealed that the transcription levels of 479 genes changed between the cell growth stage (6 h) and the citrate synthesis stage (12 h, 24 h, 36 h, and 48 h). In the glycolysis pathway, triosephosphate isomerase was up-regulated, whereas pyruvate kinase was down-regulated. Two cytosol ATP-citrate lyases, which take part in the cycle of citrate synthesis, were up-regulated, and may coordinate with the alternative oxidases in the alternative respiratory pathway for energy balance. Finally, deletion of the oxaloacetate acetylhydrolase gene in H915-1 eliminated oxalate formation but neither influence on pH decrease nor difference in citrate production were observed. PMID:28106122

Overexpression, crystallization and preliminary X-­ray crystallographic analysis of erythronate-4-phosphate dehydrogenase from Pseudomonas aeruginosa

PubMed Central

Ha, Jun Yong; Lee, Ji Hyun; Kim, Kyoung Hoon; Kim, Do Jin; Lee, Hyung Ho; Kim, Hye-Kyung; Yoon, Hye-Jin; Suh, Se Won

2006-01-01

The enzyme erythronate-4-phosphate dehydrogenase catalyses the conversion of erythronate-4-phosphate to 3-hydroxy-4-phospho-hydroxy-α-ketobutyrate. It belongs to the d-isomer-specific 2-hydroxyacid dehydrogenase family. It is essential for de novo biosynthesis of vitamin B6 (pyridoxine). Erythronate-4-­phosphate dehydrogenase from Pseudomonas aeruginosa, a homodimeric enzyme consisting of two identical 380-residue subunits, has been overexpressed in Escherichia coli with a C-terminal purification tag and crystallized at 297 K using 0.7 M ammonium dihydrogen phosphate, 0.4 M ammonium tartrate, 0.1 M sodium citrate pH 5.6 and 10 mM cupric chloride. X-ray diffraction data were collected to 2.20 Å from a crystal grown in the presence of NADH. The crystals belong to the orthorhombic space group P212121, with unit-cell parameters a = 84.77, b = 101.28, c = 142.58 Å. A dimeric molecule is present in the asymmetric unit, giving a crystal volume per protein weight (V M) of 3.64 Å3 Da−1 and a solvent content of 66%. PMID:16511285

Polynucleotide 3′-terminal Phosphate Modifications by RNA and DNA Ligases

PubMed Central

Zhelkovsky, Alexander M.; McReynolds, Larry A.

2014-01-01

RNA and DNA ligases catalyze the formation of a phosphodiester bond between the 5′-phosphate and 3′-hydroxyl ends of nucleic acids. In this work, we describe the ability of the thermophilic RNA ligase MthRnl from Methanobacterium thermoautotrophicum to recognize and modify the 3′-terminal phosphate of RNA and single-stranded DNA (ssDNA). This ligase can use an RNA 3′p substrate to generate an RNA 2′,3′-cyclic phosphate or convert DNA3′p to ssDNA3′pp5′A. An RNA ligase from the Thermus scotoductus bacteriophage TS2126 and a predicted T4 Rnl1-like protein from Thermovibrio ammonificans, TVa, were also able to adenylate ssDNA 3′p. These modifications of RNA and DNA 3′-phosphates are similar to the activities of RtcA, an RNA 3′-phosphate cyclase. The initial step involves adenylation of the enzyme by ATP, which is then transferred to either RNA 3′p or DNA 3′p to generate the adenylated intermediate. For RNA 3′pp5′A, the third step involves attack of the adjacent 2′ hydroxyl to generate the RNA 2′,3′-cyclic phosphate. These steps are analogous to those in classical 5′ phosphate ligation. MthRnl and TS2126 RNA ligases were not able to modify a 3′p in nicked double-stranded DNA. However, T4 DNA ligase and RtcA can use 3′-phosphorylated nicks in double-stranded DNA to produce a 3′-adenylated product. These 3′-terminal phosphate-adenylated intermediates are substrates for deadenylation by yeast 5′Deadenylase. Our findings that classic ligases can duplicate the adenylation and phosphate cyclization activity of RtcA suggests that they have an essential role in metabolism of nucleic acids with 3′-terminal phosphates. PMID:25324547

Hair sheep blood, citrated or defibrinated, fulfills all requirements of blood agar for diagnostic microbiology laboratory tests.

PubMed

Yeh, Ellen; Pinsky, Benjamin A; Banaei, Niaz; Baron, Ellen Jo

2009-07-03

Blood agar is used for the identification and antibiotic susceptibility testing of many bacterial pathogens. In the developing world, microbiologists use human blood agar because of the high cost and inhospitable conditions for raising wool sheep or horses to supply blood. Many pathogens either fail to grow entirely or exhibit morphologies and hemolytic patterns on human blood agar that confound colony recognition. Furthermore, human blood can be hazardous to handle due to HIV and hepatitis. This study investigated whether blood from hair sheep, a hardy, low-maintenance variety of sheep adapted for hot climates, was suitable for routine clinical microbiology studies. Hair sheep blood obtained by jugular venipuncture was anticoagulated by either manual defibrination or collection in human blood bank bags containing citrate-phosphate-dextrose. Trypticase soy 5% blood agar was made from both forms of hair sheep blood and commercial defibrinated wool sheep blood. Growth characteristics, colony morphologies, and hemolytic patterns of selected human pathogens, including several streptococcal species, were evaluated. Specialized identification tests, including CAMP test, reverse CAMP test, and satellite colony formation with Haemophilus influenzae and Abiotrophia defectiva were also performed. Mueller-Hinton blood agar plates prepared from the three blood types were compared in antibiotic susceptibility tests by disk diffusion and E-test. The results of all studies showed that blood agar prepared from citrated hair sheep blood is suitable for microbiological tests used in routine identification and susceptibility profiling of human pathogens. The validation of citrated hair sheep blood eliminates the labor-intensive and equipment-requiring process of manual defibrination. Use of hair sheep blood, in lieu of human blood currently used by many developing world laboratories and as an alternative to cost-prohibitive commercial sheep blood, offers the opportunity to

Spatial Pattern of Copper Phosphate Precipitation Involves in Copper Accumulation and Resistance of Unsaturated Pseudomonas putida CZ1 Biofilm.

PubMed

Chen, Guangcun; Lin, Huirong; Chen, Xincai

2016-12-28

Bacterial biofilms are spatially structured communities that contain bacterial cells with a wide range of physiological states. The spatial distribution and speciation of copper in unsaturated Pseudomonas putida CZ1 biofilms that accumulated 147.0 mg copper per g dry weight were determined by transmission electron microscopy coupled with energy dispersive X-ray analysis, and micro-X-ray fluorescence microscopy coupled with micro-X-ray absorption near edge structure (micro-XANES) analysis. It was found that copper was mainly precipitated in a 75 μm thick layer as copper phosphate in the middle of the biofilm, while there were two living cell layers in the air-biofilm and biofilm-medium interfaces, respectively, distinguished from the copper precipitation layer by two interfaces. The X-ray absorption fine structure analysis of biofilm revealed that species resembling Cu₃(PO₄)₂ predominated in biofilm, followed by Cu-Citrate- and Cu-Glutathione-like species. Further analysis by micro-XANES revealed that 94.4% of copper were Cu₃(PO₄)₂-like species in the layer next to the air interface, whereas the copper species of the layer next to the medium interface were composed by 75.4% Cu₃(PO₄)₂, 10.9% Cu-Citrate-like species, and 11.2% Cu-Glutathione-like species. Thereby, it was suggested that copper was initially acquired by cells in the biofilm-air interface as a citrate complex, and then transported out and bound by out membranes of cells, released from the copper-bound membranes, and finally precipitated with phosphate in the extracellular matrix of the biofilm. These results revealed a clear spatial pattern of copper precipitation in unsaturated biofilm, which was responsible for the high copper tolerance and accumulation of the biofilm.

Study on the Antimicrobial Properties of Citrate-Based Biodegradable Polymers

PubMed Central

Su, Lee-Chun; Xie, Zhiwei; Zhang, Yi; Nguyen, Kytai Truong; Yang, Jian

2014-01-01

Citrate-based polymers possess unique advantages for various biomedical applications since citric acid is a natural metabolism product, which is biocompatible and antimicrobial. In polymer synthesis, citric acid also provides multiple functional groups to control the crosslinking of polymers and active binding sites for further conjugation of biomolecules. Our group recently developed a number of citrate-based polymers for various biomedical applications by taking advantage of their controllable chemical, mechanical, and biological characteristics. In this study, various citric acid derived biodegradable polymers were synthesized and investigated for their physicochemical and antimicrobial properties. Results indicate that citric acid derived polymers reduced bacterial proliferation to different degrees based on their chemical composition. Among the studied polymers, poly(octamethylene citrate) showed ~70–80% suppression to microbe proliferation, owing to its relatively higher ratio of citric acid contents. Crosslinked urethane-doped polyester elastomers and biodegradable photoluminescent polymers also exhibited significant bacteria reduction of ~20 and ~50% for Staphylococcus aureus and Escherichia coli, respectively. Thus, the intrinsic antibacterial properties in citrate-based polymers enable them to inhibit bacteria growth without incorporation of antibiotics, silver nanoparticles, and other traditional bacteria-killing agents suggesting that the citrate-based polymers are unique beneficial materials for wound dressing, tissue engineering, and other potential medical applications where antimicrobial property is desired. PMID:25023605

Pretreatment With Caffeine Citrate to Increase Seizure Duration During Electroconvulsive Therapy: A Case Series.

PubMed

Pinkhasov, Aaron; Biglow, Michael; Chandra, Subhash; Pica, Tiffany

2016-04-01

Due to the shortage of parenteral caffeine and sodium benzoate, patients were pretreated with caffeine citrate to increase therapeutic seizure duration during electroconvulsive therapy (ECT). To date, no data are available on the use of caffeine citrate during ECT. This retrospective case series was done to demonstrate utilization of caffeine citrate as a substitute for caffeine and sodium benzoate in optimizing ECT. Medical records were reviewed to identify patients who received ECT and caffeine citrate. Physician notes were reviewed to determine the parameters of the ECT procedure, the seizure length, and the dose of caffeine citrate. Each chart was thoroughly studied to find the relationship between seizure duration and dose of caffeine citrate. Of the 12 ECT treatments utilizing caffeine citrate, 9 achieved at least 1 session lasting >30 seconds with an average seizure duration of 35 seconds. Increase in seizure duration ranged from -41% to 276% with an average increase of 48%. Only 3 treatment sessions utilizing caffeine citrate showed no increase in seizure duration. Doses ranged from 120 to 600 mg of both oral and parenteral caffeine citrate. Although increase in seizure duration was achieved for the majority of the ECT sessions, no dose-response correlation could be made. No significant adverse reactions were noted with the use of caffeine citrate during ECT. It was determined that, much like caffeine and sodium benzoate, caffeine citrate does increase the seizure duration. However, this response did vary due to many reasons including small sample size, concomitant medications, duration of illness, and number of ECTs they received in the past and how long ago they received the last ECT. Further research is required to elucidate the effect of these variables on seizure duration. © The Author(s) 2014.

Sildenafil citrate (Viagra) enhances vasodilatation by atrial natriuretic peptide in normal dogs.

PubMed

Ishikura, Fuminobu; Beppu, Shintaro; Asanuma, Toshihiko; Seward, James B; Khandheria, Bijoy K

2007-12-01

Sildenafil citrate (Viagra) is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5, which might enhance the vasorelaxant and natriuretic actions of atrial natriuretic peptide (ANP) in patients with heart failure. The objective of this study was to examine the combined effect of Viagra on hemodynamic changes during infusion of exogenous ANP. Healthy male beagles were used to assess systemic blood pressure, pulmonary artery pressure (PAP), and plasma levels of cGMP. After hemodynamic variables were measured, 0.1 microg.kg(-1).min(-1) of ANP was given during this study. One hour after initiating infusion of ANP, 2 mg/kg of sildenafil citrate or vehicle was given orally via a nasogastric tube. Hemodynamic changes were measured before and 1 h after these administrations. Mean systemic and PAP decreased during infusion of ANP, and further decreased after sildenafil citrate administration, however, mean systemic blood pressure decreased within 10 mmHg. Plasma levels of cGMP also increased after sildenafil citrate administration. In normal dogs, sildenafil citrate enhances the vasodilator effect of ANP by increasing the cGMP level, however, the concomitant use of sildenafil citrate with ANP will not induce severe hypotension.

GALLIUM CITRATE, A NEW SENSITIZER OF CELLS TO HYPERTHERMIA

PubMed Central

Shinohara, Kunio; Kawakami, Noriko; Kugotani, Maho; Nakano, Hisako

1988-01-01

The killing effects of heat were studied on cultured mammalian cells (L5178Y) pre‐incubated with gallium (Ga) citrate, which is a popular tumor‐imaging diagnostic agent. The cells showed higher sensitivity to heat when they were pre‐incubated with Ga‐citrate. The pre‐incubated cells showed decreased ATP levels, and this may be responsible for the heat‐sensitizing effect. PMID:3128502

Comparison of Success of Clomiphene citrate and Letrozole in Ovulation Induction.

PubMed

Saha, J; Akhter, S; Prasad, I; Siddiq, S

2016-01-01

The study was carried out to evaluate which drug is better in ovulation induction between clomiphene citrate and letrozole. The study was carried out in the infertility unit of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka and Centre for Assisted Reproduction (CARE) at Bangladesh Institute of Research and Rehabilitation in Diabetes Endocrine and Metabolic Disorders (BIRDEM), Dhaka from January 2007 to December 2007. One hundred and sixty five cases were taken for the study. It was a prospective interventional comparative study of clomiphene citrate and letrozole in infertile cases. The patients were divided into three groups. Group I--newly detected cases of sub fertility studied with clomiphene citrate. Group II--clomiphene citrate resistant cases studied with letrozole, Group III--newly detected cases of sub fertility studied with letrozole. The cases were followed up for outcome; (ovulation). The TVS was done on 12th or 13th day of menstruation and level of serum progesterone on 21st day of menstrual cycle to see the evidence of ovulation. Endometrial thickness was also measured. The data was collected on a predesigned questionnaire. The variables that influenced the study were-age, occupation, socioeconomic status, menstrual cycle, marital age, parity, history of MR, history of abortion, past medical and surgical history. In the current study it was observed that the signs of ovulation were significantly (p<0.05) higher in Group I treated with clomiphene citrate in comparison to Group II clomiphene citrate resistant cases treated with letrozole. The rate of ovulation was higher in Group I than that of Group III treated with letrozole, but the difference was not statistically significant (p>0.05). The signs of ovulation were present in 45(81.8%) cases in Group I, 33(60.0%) cases in Group II and 37(67.3%) cases in Group III. This findings of the study suggested that clomiphene citrate is higher successful than letrozole though not statistically

The equilibrium of the reaction catalysed by citrate oxaloacetate-lyase

PubMed Central

Tate, S. S.; Datta, S. P.

1965-01-01

1. A method of preparation and purification of citrate oxaloacetate-lyase (EC 4.1.3.6) from Aerobacter aerogenes is described. 2. The equilibrium of this reaction has been determined at pH 8·4 and 25°. It has been shown that K, i.e. [citrate3−]/[oxaloacetateketo2−][acetate −], is 3·08±0·72, but that Kapp., i.e. [total citrate]/[total oxaloacetate][total acetate], is markedly affected by the initial concentrations of the reactants and magnesium. 3. The free-energy change during the cleavage of citrate has been calculated and compared with data from other sources. 4. The free energy of hydrolysis of acetyl-CoA has been evaluated from the present data. 5. A detailed knowledge of the interactions of the reactants with metal ions has been shown to be important in the calculation of the equilibrium constant and related thermodynamic functions. PMID:14348207

Mayenite Synthesized Using the Citrate Sol-Gel Method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ude, Sabina N; Rawn, Claudia J; Meisner, Roberta A

2014-01-01

A citrate sol-gel method has been used to synthesize mayenite (Ca12Al14O33). X-ray powder diffraction data show that the samples synthesized using the citrate sol-gel method contained CaAl2O4 and CaCO3 along with mayenite when fired ex-situ in air at 800 C but were single phase when fired at 900 C and above. Using high temperature x-ray diffraction, data collected in-situ in air at temperatures of 600 C and below showed only amorphous content; however, data collected at higher temperatures indicated the first phase to crystallize is CaCO3. High temperature x-ray diffraction data collected in 4% H2/96% N2 does not show themore » presence of CaCO3, and Ca12Al14O33 starts to form around 850 C. In comparison, x-ray powder diffraction data collected ex-situ on samples synthesized using traditional solid-state synthesis shows that single phase was not reached until samples were fired at 1350 C. DTA/TGA data collected either in a nitrogen environment or air on samples synthesized using the citrate gel method suggest the complete decomposition of metastable phases and the formation of mayenite at 900 C, although the phase evolution is very different depending on the environment. Brunauer-Emmett-Teller (BET) measurements showed a slightly higher surface area of 7.4 0.1 m2/g in the citrate gel synthesized samples compared to solid-state synthesized sample with a surface area of 1.61 0.02 m2/g. SEM images show a larger particle size for samples synthesized using the solid-state method compared to those synthesized using the citrate gel method.« less

78 FR 34642 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Preliminary Results of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-10

... monopotassium forms of potassium citrate.\\1\\ Sodium citrate also includes both trisodium citrate and monosodium... Tariff Schedule of the United States (``HTSUS''), respectively. Potassium citrate and crude calcium... include citric acid, sodium citrate, and potassium citrate are classifiable under 3824.90.9290 of the...

77 FR 47370 - Citric Acid and Certain Citrate Salts from the People's Republic of China: Intent To Rescind...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-08

... order includes all grades and granulation sizes of citric acid, sodium citrate, and potassium citrate in... includes blends of citric acid, sodium citrate, and potassium citrate; as well as blends with other ingredients, such as sugar, where the unblended form(s) of citric acid, sodium citrate, and potassium citrate...

Extracellular Citrate Affects Critical Elements of Cancer Cell Metabolism and Supports Cancer Development In Vivo.

PubMed

Mycielska, Maria E; Dettmer, Katja; Rümmele, Petra; Schmidt, Katharina; Prehn, Cornelia; Milenkovic, Vladimir M; Jagla, Wolfgang; Madej, Gregor M; Lantow, Margareta; Schladt, Moritz; Cecil, Alexander; Koehl, Gudrun E; Eggenhofer, Elke; Wachsmuth, Christian J; Ganapathy, Vadivel; Schlitt, Hans J; Kunzelmann, Karl; Ziegler, Christine; Wetzel, Christian H; Gaumann, Andreas; Lang, Sven A; Adamski, Jerzy; Oefner, Peter J; Geissler, Edward K

2018-05-15

Glycolysis and fatty acid synthesis are highly active in cancer cells through cytosolic citrate metabolism, with intracellular citrate primarily derived from either glucose or glutamine via the tricarboxylic acid cycle. We show here that extracellular citrate is supplied to cancer cells through a plasma membrane-specific variant of the mitochondrial citrate transporter (pmCiC). Metabolomic analysis revealed that citrate uptake broadly affected cancer cell metabolism through citrate-dependent metabolic pathways. Treatment with gluconate specifically blocked pmCiC and decreased tumor growth in murine xenografts of human pancreatic cancer. This treatment altered metabolism within tumors, including fatty acid metabolism. High expression of pmCiC was associated with invasion and advanced tumor stage across many human cancers. These findings support the exploration of extracellular citrate transport as a novel potential target for cancer therapy. Significance: Uptake of extracellular citrate through pmCiC can be blocked with gluconate to reduce tumor growth and to alter metabolic characteristics of tumor tissue. Cancer Res; 78(10); 2513-23. ©2018 AACR . ©2018 American Association for Cancer Research.

Perinatal and Hemodynamic Evaluation of Sildenafil Citrate for Preeclampsia Treatment: A Randomized Controlled Trial.

PubMed

Trapani, Alberto; Gonçalves, Luis Flavio; Trapani, Thamyris Finger; Vieira, Simone; Pires, Marilen; Pires, Maria Marlene de Souza

2016-08-01

To evaluate whether therapy with sildenafil citrate prolongs gestation in women with preeclampsia. In a randomized double-blind, placebo-controlled trial, 100 singleton pregnancies with preeclampsia between 24 and 33 weeks of gestation were randomized to 50 mg oral sildenafil citrate every 8 hours or placebo. The primary outcome was prolongation of pregnancy from randomization to delivery. Secondary outcomes were changes in resistance indices of uterine, umbilical, and middle cerebral arteries by Doppler, fetal and maternal complications, and adverse neonatal outcomes. Power analysis estimated that to detect a difference of 5 days in pregnancy duration, 43 patients would have to be randomized to each group. From June 2013 to October 2015, 50 patients were randomized to each group. Pregnancy duration was on average 4 days longer (14.4 days, 95% confidence interval [CI] 12.5-16.6 days compared with 10.4 days, 95% CI 8.4-12.3 days, P=.008) and percent reduction in pulsatility indices of uterine and umbilical arteries higher (22.5% and 18.5%, compared with placebo 2.1% and 2.5%, P<.001) for patients treated with sildenafil compared with placebo. Maternal blood pressure before and 24 hours after randomization was lower with sildenafil (sildenafil: 100.3±5.6 mm Hg compared with 116.4±5.1 mm Hg, P<.05; placebo: 110.6±6.2 mm Hg compared with 114.7±6.5 mm Hg, P=.21). There was no difference in perinatal morbidity, mortality, or adverse effects between groups. Therapy with sildenafil citrate was associated with pregnancy prolongation of approximately 4 days compared with placebo in women with preeclampsia. Brazilian Registry of Clinical Trials, www.ensaiosclinicos.gov.br, RBR-8qj4p5.

Sensitizing effects of gallium citrate on hyperthermic cell killing in vitro.

PubMed

Miyazaki, N; Nakano, H; Kawakami, N; Kugotani, M; Nishihara, K; Aoki, Y; Shinohara, K

2000-01-01

The lethal effects of gallium citrate in combination with heat were studied using four cell lines, L5178Y, FM3A, P388 and HeLa. Cells were incubated with different concentrations (0.2 2 mM) of gallium citrate at 37 degrees C for 24 h and heated at a range of temperatures from 40-44 degrees C for various time periods up to 6 h in the absence of gallium citrate. Survival and cell viability were determined by clonogenic assay and the dye-exclusion test, respectively. All of the cell lines tested were insensitive to heat below 41 degrees C, but were very sensitive to heat above 43 degrees C. Gallium citrate was cytotoxic to these cell lines at different levels: P388 and HeLa were far more sensitive than L5178Y and FM3A. The killing effects of heat at 41 degrees C were greatly enhanced by gallium citrate in L5178Y and P388 cells. The Arrhenius analysis for the lethal effect of heat, determined by clonogenic assay, in L5178Y cells showed that the transition temperature was remarkably decreased for the gallium-treated cells from approximately 43 degrees C to 41 degrees C. The mechanism for this decrease in the transition temperature may be attributable to the additional effects of gallium citrate on energy metabolism. Preincubation with 0.05 mM gallium citrate at 37 degrees C for 7 days also enhanced heat sensitization at 41 degrees C in L5178Y. This preincubation condition may correspond to the condition for the continuous infusion of gallium that is clinically used for cancer treatment. In contrast, treatment with gallium did not greatly enhance the sensitivity of FM3A or HeLa cells to heat at 41 degrees C, but the effects of gallium were significant.

The Effect of Moderate Dietary Protein and Phosphate Restriction on Calcium-Phosphate Homeostasis in Healthy Older Cats.

PubMed

Geddes, R F; Biourge, V; Chang, Y; Syme, H M; Elliott, J

2016-09-01

Dietary phosphate and protein restriction decreases plasma PTH and FGF-23 concentrations and improves survival time in azotemic cats, but has not been examined in cats that are not azotemic. Feeding a moderately protein- and phosphate-restricted diet decreases PTH and FGF-23 in healthy older cats and thereby slows progression to azotemic CKD. A total of 54 healthy, client-owned cats (≥ 9 years). Prospective double-blinded randomized placebo-controlled trial. Cats were assigned to test diet (protein 76 g/Mcal and phosphate 1.6 g/Mcal) or control diet (protein 86 g/Mcal and phosphate 2.6 g/Mcal) and monitored for 18 months. Changes in variables over time and effect of diet were assessed by linear mixed models. A total of 26 cats ate test diet and 28 cats ate control diet. There was a significant effect of diet on urinary fractional excretion of phosphate (P = 0.045), plasma PTH (P = 0.005), and ionized calcium concentrations (P = 0.018), but not plasma phosphate, FGF-23, or creatinine concentrations. Plasma PTH concentrations did not significantly change in cats fed the test diet (P = 0.62) but increased over time in cats fed the control diet (P = 0.001). There was no significant treatment effect of the test diet on development of azotemic CKD (3 of 26 (12%) test versus 3 of 28 (11%) control, odds ratio 1.09 (95% CI 0.13-8.94), P = 0.92). Feeding a moderately protein- and phosphate-restricted diet has effects on calcium-phosphate homeostasis in healthy older cats and is well tolerated. This might have an impact on renal function and could be useful in early chronic kidney disease. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Spirocyclic character of ixazomib citrate revealed by comprehensive XRD, NMR and DFT study

NASA Astrophysics Data System (ADS)

Skorepova, Eliska; Čerňa, Igor; Vlasáková, Růžena; Zvoníček, Vít; Tkadlecová, Marcela; Dušek, Michal

2017-11-01

Ixazomib citrate is a very recently approved anti-cancer drug. Until now, to the best of our knowledge, no one has been able to solve any crystal structures of this compound. In this work, we present the crystal structures of two isostructural solvates of ixazomib citrate. In all currently available literature, the molecule is characterized as containing a single optically active carbon atom and a borate cycle formed when ixazomib is reacted with citric acid to form a stabilized ixazomib citrate that can be administered orally. However, the crystal structures revealed that none of the up-to-date presented structural formulas of ixazomib citrate are fully accurate. In addition to the citrate ring, another 5-membered ring is formed. These two rings are connected by the boron atom, making this compound a spirocyclic borate. By spirocyclization, the boron atom becomes tetrahedral and therefore optically active. In the crystal structures, ixazomib citrate was found to be in forms of two RR and RS stereoisomers. The results are supported by solid-state and solution NMR and DFT quantum mechanical calculations.

Management strategies for ovulation induction in women with polycystic ovary syndrome and known clomifene citrate resistance.

PubMed

Palomba, Stefano; Falbo, Angela; Zullo, Fulvio

2009-12-01

Clomifene citrate is the first and the most used agent for inducing ovulation in patients affected by polycystic ovary syndrome (PCOS). About 60-85% of PCOS women ovulated under clomifene citrate, whereas the others were defined clomifene citrate-resistant. The purpose of the current review will be to describe treatment strategies to induce ovulation in infertile PCOS patients with clomifene citrate resistance. Clomifene citrate and metformin association are a valid option for inducing ovulation in clomifene citrate-resistant PCOS patients. Surgical ovulation induction by laparoscopic ovarian drilling should be reserved to well selected cases. Excellent preliminary results are obtained using new drug formulations, such as aromatase inhibitors. In clomifene citrate-resistant PCOS patients, clomifene citrate and metformin combination and laparoscopic ovarian drilling, in selected cases, should be considered before gonadotropin administration. The efficacy of the other treatments must be confirmed in future well designed studies.

Effect of sildenafil citrate (Viagra) on coronary flow in normal subjects.

PubMed

Ishikura, Fuminobu; Beppu, Shintaro; Ueda, Hiroaki; Nehra, Ajay; Khandheria, Bijoy K

2008-01-01

The purpose of this study was to evaluate the effect of sildenafil citrate (Viagra) on coronary function in normal subjects. 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). 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. 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.

SERS substrates fabricated using ceramic filters for the detection of bacteria: Eliminating the citrate interference

NASA Astrophysics Data System (ADS)

Mosier-Boss, P. A.; Sorensen, K. C.; George, R. D.; Sims, P. C.; O'braztsova, A.

2017-06-01

It was found that spectra obtained for bacteria on SERS substrates fabricated by filtering citrate-generated Ag nanoparticles (NPs) onto rigid, ceramic filters exhibited peaks due to citrate as well as the bacteria. In many cases the citrate spectrum overwhelmed that of the bacteria. Given the simplicity of the method to prepare these substrates, means of eliminating this citrate interference were explored. It was found that allowing a mixture of bacteria suspension and citrate-generated Ag NPs to incubate prior to filtering onto the ceramic filter eliminated this interference.

Effects of citrate on hexavalent chromium reduction by structural Fe(II) in nontronite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Xiaolei; Dong, Hailiang; Yang, Xuewei

Iron-bearing clay minerals and organic matter are two important components in natural environments that influence hexavalent chromium (Cr(VI)) reduction. Previous studies have shown that organic ligands could influence Cr(VI) reduction by aqueous Fe2+ and pyrite. However, the effects of organic ligands on Cr(VI) reduction by structural Fe(II) in clays are not well understood. In this study, the effects of citrate on Cr(VI) reduction by nontronite (NAu-2) were investigated under near neutral pH condition (pH=6). Our results showed that the presence of citrate decreased the rate but increased the amount of Cr(VI) reduction by structural Fe(II) in NAu-2. The decreased reactionmore » rate was likely due to competitive sorption of citrate and polyanionic dichromate (Cr2O7- ), because sorption of dichromate appeared to be the first step for subsequent Cr(VI) reduction. The increased amount of Cr(VI) reduction in the presence of citrate was likely because citrate provided additional reducing power through ligand-metal electron transfer in the presence of soluble Fe 3+ derived from dissolution of reduced NAu-2. Soluble Cr(III)-citrate complex was the possible form of reduced chromium when citrate was present. In contrast, nanometer-sized Cr2O3 particles were the product of Cr(VI) reduction by reduced NAu-2 without citrate. Our study highlights the importance of organic ligands on Cr(VI) reduction and immobilization when iron-bearing clay minerals are applied to treat Cr(VI) contaminant in organic matter rich environments.« less

Assembly of citrate gold nanoparticles on hydrophilic monolayers

NASA Astrophysics Data System (ADS)

Vikholm-Lundin, Inger; Rosqvist, Emil; Ihalainen, Petri; Munter, Tony; Honkimaa, Anni; Marjomäki, Varpu; Albers, Willem M.; Peltonen, Jouko

2016-08-01

Self-assembled monolayers (SAMs) as model surfaces were linked onto planar gold films thorough lipoic acid or disulfide groups. The molecules used were polyethylene glycol (EG-S-S), N-[tris-(hydroxymethyl)methyl]acrylamide polymers with and without lipoic acid (Lipa-pTHMMAA and pTHMMAA) and a lipoic acid triazine derivative (Lipa-MF). All the layers, but Lipa-MF with a primary amino group were hydroxyl terminated. The layers were characterized by contact angle measurements and atomic force microscopy, AFM. Citrate stabilized nanoparticles, AuNPs in water and phosphate buffer were allowed to assemble on the layers for 10 min and the binding was followed in real-time with surface plasmon resonance, SPR. The SPR resonance curves were observed to shift to higher angles and become increasingly damped, while also the peaks strongly broaden when large nanoparticles assembled on the surface. Both the angular shift and the damping of the curve was largest for nanoparticles assembling on the EG-S-S monolayer. High amounts of particles were also assembled on the pTHMMAA layer without the lipoic acid group, but the damping of the curve was considerably lower with a more even distribution of the particles. Topographical images confirmed that the highest number of particles were assembled on the polyethylene glycol monolayer. By increasing the interaction time more particles could be assembled on the surface.

[Effect of glucose and lactose on the utilization of citrate by Lactobacillus casei subsp. rhamnosus ATCC 7469].

PubMed

Benito de Cárdenas, I L; Medina, R; Oliver, G

1992-01-01

The utilization of citrate by Lactobacillus casei subsp. rhamnosus ATCC 7469 in a complex medium containing glucose, lactose or citrate was investigated, as an approach to the question of the transport of this acid and the possible relationship with the production of flavour compounds (diacetyl and acetoin). This lactobacillus uses citrate as an energy source in the absence of carbohydrates. External pH and growth increases when citrate is added to complex medium. The presence of citrate does not affect glucose uptake. L. casei ATCC 7469 possibly uses a transport system for citrate utilization, and citrate uptake seems to be under glucose or lactose control. Lactose only inhibits the entrance of citrate at high concentration while the utilization of this acid was negatively regulated by low glucose concentration.

Inhaled fentanyl citrate improves exercise endurance during high-intensity constant work rate cycle exercise in chronic obstructive pulmonary disease.

PubMed

Jensen, Dennis; Alsuhail, Abdullah; Viola, Raymond; Dudgeon, Deborah J; Webb, Katherine A; O'Donnell, Denis E

2012-04-01

Activity limitation and dyspnea are the dominant symptoms of chronic obstructive pulmonary disease (COPD). Traditionally, efforts to alleviate these symptoms have focused on improving ventilatory mechanics, reducing ventilatory demand, or both of these in combination. Nevertheless, many patients with COPD remain incapacitated by dyspnea and exercise intolerance despite optimal therapy. To determine the effect of single-dose inhalation of nebulized fentanyl citrate (a μ-opioid agonist drug) on exercise tolerance and dyspnea in COPD. In a randomized, double-blind, placebo-controlled, crossover study, 12 stable patients with COPD (mean ± standard error of the mean post-β(2)-agonist forced expiratory volume in one second [FEV(1)] and FEV(1) to forced vital capacity ratio of 69% ± 4% predicted and 49% ± 3%, respectively) received either nebulized fentanyl citrate (50 mcg) or placebo on two separate days. After each treatment, patients performed pulmonary function tests and a symptom-limited constant work rate cycle exercise test at 75% of their maximum incremental work rate. There were no significant postdose differences in spirometric parameters or plethysmographic lung volumes. Neither the intensity nor the unpleasantness of perceived dyspnea was, on average, significantly different at isotime (5.0 ± 0.6 minutes) or at peak exercise after treatment with fentanyl citrate vs. placebo. Compared with placebo, fentanyl citrate was associated with 1) increased exercise endurance time by 1.30 ± 0.43 minutes or 25% ± 8% (P=0.01); 2) small but consistent increases in dynamic inspiratory capacity by ∼0.10 L at isotime and at peak exercise (both P≤0.03); and 3) no concomitant change in ventilatory demand, breathing pattern, pulmonary gas exchange, and/or cardiometabolic function during exercise. The mean rate of increase in dyspnea intensity (1.2 ± 0.3 vs. 2.9 ± 0.8 Borg units/minute, P=0.03) and unpleasantness ratings (0.5 ± 0.2 vs. 2.9 ± 1.3 Borg units

A Phex Mutation in a Murine Model of X-linked Hypophosphatemia Alters Phosphate Responsiveness of Bone Cells

PubMed Central

Ichikawa, Shoji; Austin, Anthony M.; Gray, Amie K.; Econs, Michael J.

2011-01-01

Mutations in the PHEX gene cause X-linked hypophosphatemia (XLH). Hypophosphatemia in XLH results from increased circulating levels of a phosphaturic hormone, fibroblast growth factor 23 (FGF23), which inhibits renal phosphate reabsorption and 1,25-dihydroxyvitamin D (calcitriol) synthesis. The current standard therapy for XLH – high dose phosphate and calcitriol – further increases FGF23 concentrations, suggesting that patients with XLH may have an altered response to extracellular phosphate. To test for the presence of abnormal phosphate responsiveness, we compared serum biochemistries and femoral Fgf23 mRNA expression between wild-type mice, murine models of XLH (PhexK496X) and hyperphosphatemic tumoral calcinosis (Galnt3 -/-), and Galnt3/Phex double mutant mice. Phex mutant mice had not only increased Fgf23 expression, but also reduced proteolytic cleavage of intact Fgf23 protein, resulting in markedly elevated intact Fgf23 levels and consequent hypophosphatemia. In contrast, despite markedly increased Fgf23 expression, Galnt3 knockout mice had significantly high proteolytic cleavage of Fgf23 protein, leading to low intact Fgf23 concentrations and hyperphosphatemia. Galnt3/Phex double mutant mice had an intermediate biochemical phenotype between wild-type and Phex mutant mice, including slightly elevated intact Fgf23 concentrations with milder hypophosphatemia. Despite the hypophosphatemia, double mutant mice attempted to reduce serum phosphate back to the level of Phex mutant mice by up-regulating Fgf23 expression as much as 24 fold higher than Phex mutant mice. These data suggest that Phex mutations alter the responsiveness of bone cells to extracellular phosphate concentrations and may create a lower set point for “normal” phosphate levels. PMID:22006791

A Phex mutation in a murine model of X-linked hypophosphatemia alters phosphate responsiveness of bone cells.

PubMed

Ichikawa, Shoji; Austin, Anthony M; Gray, Amie K; Econs, Michael J

2012-02-01

Mutations in the PHEX gene cause X-linked hypophosphatemia (XLH). Hypophosphatemia in XLH results from increased circulating levels of a phosphaturic hormone, fibroblast growth factor 23 (FGF23), which inhibits renal phosphate reabsorption and 1,25-dihydroxyvitamin D (calcitriol) synthesis. The current standard therapy for XLH--high-dose phosphate and calcitriol--further increases FGF23 concentrations, suggesting that patients with XLH may have an altered response to extracellular phosphate. To test for the presence of abnormal phosphate responsiveness, we compared serum biochemistries and femoral Fgf23 mRNA expression between wild-type mice, murine models of XLH (Phex(K496X)) and hyperphosphatemic tumoral calcinosis (Galnt3(-/-)), and Galnt3/Phex double-mutant mice. Phex mutant mice had not only increased Fgf23 expression but also reduced proteolytic cleavage of intact Fgf23 protein, resulting in markedly elevated intact Fgf23 levels and consequent hypophosphatemia. In contrast, despite markedly increased Fgf23 expression, Galnt3 knockout mice had significantly high proteolytic cleavage of Fgf23 protein, leading to low intact Fgf23 concentrations and hyperphosphatemia. Galnt3/Phex double-mutant mice had an intermediate biochemical phenotype between wild-type and Phex mutant mice, including slightly elevated intact Fgf23 concentrations with milder hypophosphatemia. Despite the hypophosphatemia, double-mutant mice attempted to reduce serum phosphate back to the level of Phex mutant mice by upregulating Fgf23 expression as much as 24-fold higher than Phex mutant mice. These data suggest that Phex mutations alter the responsiveness of bone cells to extracellular phosphate concentrations and may create a lower set point for "normal" phosphate levels.

SERS substrates fabricated using ceramic filters for the detection of bacteria: Eliminating the citrate interference.

PubMed

Mosier-Boss, P A; Sorensen, K C; George, R D; Sims, P C; O'braztsova, A

2017-06-05

It was found that spectra obtained for bacteria on SERS substrates fabricated by filtering citrate-generated Ag nanoparticles (NPs) onto rigid, ceramic filters exhibited peaks due to citrate as well as the bacteria. In many cases the citrate spectrum overwhelmed that of the bacteria. Given the simplicity of the method to prepare these substrates, means of eliminating this citrate interference were explored. It was found that allowing a mixture of bacteria suspension and citrate-generated Ag NPs to incubate prior to filtering onto the ceramic filter eliminated this interference. Copyright © 2017 Elsevier B.V. All rights reserved.

The role of molecular structure of sugar-phosphate backbone and nucleic acid bases in the formation of single-stranded and double-stranded DNA structures.

PubMed

Poltev, Valeri; Anisimov, Victor M; Danilov, Victor I; Garcia, Dolores; Sanchez, Carolina; Deriabina, Alexandra; Gonzalez, Eduardo; Rivas, Francisco; Polteva, Nina

2014-06-01

Our previous DFT computations of deoxydinucleoside monophosphate complexes with Na(+)-ions (dDMPs) have demonstrated that the main characteristics of Watson-Crick (WC) right-handed duplex families are predefined in the local energy minima of dDMPs. In this work, we study the mechanisms of contribution of chemically monotonous sugar-phosphate backbone and the bases into the double helix irregularity. Geometry optimization of sugar-phosphate backbone produces energy minima matching the WC DNA conformations. Studying the conformational variability of dDMPs in response to sequence permutation, we found that simple replacement of bases in the previously fully optimized dDMPs, e.g. by constructing Pyr-Pur from Pur-Pyr, and Pur-Pyr from Pyr-Pur sequences, while retaining the backbone geometry, automatically produces the mutual base position characteristic of the target sequence. Based on that, we infer that the directionality and the preferable regions of the sugar-phosphate torsions, combined with the difference of purines from pyrimidines in ring shape, determines the sequence dependence of the structure of WC DNA. No such sequence dependence exists in dDMPs corresponding to other DNA conformations (e.g., Z-family and Hoogsteen duplexes). Unlike other duplexes, WC helix is unique by its ability to match the local energy minima of the free single strand to the preferable conformations of the duplex. Copyright © 2013 Wiley Periodicals, Inc.

Comparative transcriptome analysis reveals a global insight into molecular processes regulating citrate accumulation in sweet orange (Citrus sinensis).

PubMed

Lu, Xiaopeng; Cao, Xiongjun; Li, Feifei; Li, Jing; Xiong, Jiang; Long, Guiyou; Cao, Shangyin; Xie, Shenxi

2016-12-01

Citrate, the predominant organic acid in citrus, determines the taste of these fruits. However, little is known about the synergic molecular processes regulating citrate accumulation. Using 'Dahongtiancheng' (Citrus sinensis) and 'Bingtangcheng' (C. sinensis) with significant difference in citrate, the objectives of this study were to understand the global mechanisms of high-citrate accumulation in sweet orange. 'Dahongtiancheng' and 'Bingtangcheng' exhibit significantly different patterns in citrate accumulation throughout fruit development, with the largest differences observed at 50-70 days after full bloom (DAFB). Comparative transcriptome profiling was performed for the endocarps of both cultivars at 50 and 70 DAFB. Over 34.5 million clean reads per library were successfully mapped to the reference database and 670-2630 differentially expressed genes (DEGs) were found in four libraries. Among the genes, five transcription factors were ascertained to be the candidates regulating citrate accumulation. Functional assignments of the DEGs indicated that photosynthesis, the citrate cycle and amino acid metabolism were significantly altered in 'Dahongtiancheng'. Physiological and molecular analyses suggested that high photosynthetic efficiency and partial impairment of citrate catabolism were crucial for the high-citrate trait, and amino acid biosynthesis was one of the important directions for citrate flux. The results reveal a global insight into the gene expression changes in a high-citrate compared with a low-citrate sweet orange. High accumulating efficiency and impaired degradation of citrate may be associated with the high-citrate trait of 'Dahongtiancheng'. Findings in this study increase understanding of the molecular processes regulating citrate accumulation in sweet orange. © 2016 Scandinavian Plant Physiology Society.

Temperature effect on nickel release in ammonium citrate.

PubMed

Oller, Adriana R; Cappellini, Danielle; Henderson, Rayetta G; Bates, Hudson K

2009-09-01

Leaching in ammonium citrate has been extensively used to assess the fraction of water-soluble nickel compounds present in nickel producing and using workplace aerosols. Leaching in ammonium citrate according to the first step of the Zatka protocol was found to overestimate the water-soluble nickel fraction by more than ten-fold compared to synthetic lung fluid (37 degrees C), when nickel carbonate and subsulfide were present. These results suggest that exposure matrices based on this method should be reexamined. Leaching studies of refinery particles are needed to further clarify this important issue.

Effects and mechanisms of action of sildenafil citrate in human chorionic arteries

PubMed Central

Maharaj, Chrisen H; O'Toole, Daniel; Lynch, Tadhg; Carney, John; Jarman, James; Higgins, Brendan D; Morrison, John J; Laffey, John G

2009-01-01

Objectives Sildenafil citrate, a specific phosphodiesterase-5 inhibitor, is increasingly used for pulmonary hypertension in pregnancy. Sildenafil is also emerging as a potential candidate for the treatment of intra-uterine growth retardation and for premature labor. Its effects in the feto-placental circulation are not known. Our objectives were to determine whether phosphodiesterase-5 is present in the human feto-placental circulation, and to characterize the effects and mechanisms of action of sildenafil citrate in this circulation. Study Design Ex vivo human chorionic plate arterial rings were used in all experiments. The presence of phosphodiesterase-5 in the feto-placental circulation was determined by western blotting and immunohistochemical staining. In a subsequent series of pharmacologic studies, the effects of sildenafil citrate in pre-constricted chorionic plate arterial rings were determined. Additional studies examined the role of cGMP and nitric oxide in mediating the effects of sildenafil. Results Phosphodiesterase-5 mRNA and protein was demonstrated in human chorionic plate arteries. Immunohistochemistry demonstrated phosphodiesterase-5 within the arterial muscle layer. Sildenafil citrate produced dose dependent vasodilatation at concentrations at and greater than 10 nM. Both the direct cGMP inhibitor methylene blue and the cGMP-dependent protein kinase inhibitor Rp-8-Br-PET-cGMPS significantly attenuated the vasodilation produced by sildenafil citrate. Inhibition of NO production with L-NAME did not attenuate the vasodilator effects of sildenafil. In contrast, sildenafil citrate significantly enhanced the vasodilation produced by the NO donor sodium nitroprusside. Conclusion Phosphodiesterase-5 is present in the feto-placental circulation. Sildenafil citrate vasodilates the feto-placental circulation via a cGMP dependent mechanism involving increased responsiveness to NO. PMID:19389232

Localization of the Calcium Regulated Citrate Transport Process in Proximal Tubule Cells

PubMed Central

Hering-Smith, Kathleen S.; Mao, Weibo; Schiro, Faith R.; Coleman-Barnett, Joycelynn; Pajor, Ana M.; Hamm, L. Lee

2014-01-01

Urinary citrate is an important inhibitor of calcium stone formation. Most of citrate reabsorption in the proximal tubule is thought to occur via a dicarboxylate transporter NaDC1 located in the apical membrane. OK cells, an established opossum kidney proximal tubule cell line, transport citrate but the characteristics change with extracellular calcium such that low calcium solutions stimulate total citrate transport as well as increase the apparent affinity for transport. The present studies address several fundamental properties of this novel process: the polarity of the transport process, the location of the calcium-sensitivity and whether NaDC1 is present in OK cells. OK cells grown on permeable supports exhibited apical > basolateral citrate transport. Apical transport of both citrate and succinate was sensitive to extracellular calcium whereas basolateral transport was not. Apical calcium, rather than basolateral, was the predominant determinant of changes in transport. Also 2,3-dimethylsuccinate, previously identified as an inhibitor of basolateral dicarboxylate transport, inhibited apical citrate uptake. Although the calcium-sensitive transport process in OK cells is functionally not typical NaDC1, NaDC1 is present in OK cells by Western blot and PCR. By immunolocalization studies, NaDC1 was predominantly located in discrete apical membrane or subapical areas. However by biotinylation, apical NaDC1 decreases in the apical membrane with lowering calcium. In sum, OK cells express a calcium-sensitive/regulated dicarboxylate process at the apical membrane which responds to variations in apical calcium. Despite the functional differences of this process compared to NaDC1, NaDC1 is present in these cells, but predominantly in subapical vesicles. PMID:24652587

Urethral dysfunction due to alloxan-induced diabetes. Urodynamic evaluation and action of sildenafil citrate.

PubMed

Gomes de Souza Pegorare, Ana Beatriz; Gonçalves, Marco Antonio; Martiniano de Oliveira, Alessandra; Rodrigues Junior, Antonio Antunes; Tucci, Silvio; Suaid, Haylton Jorge

2014-04-01

To evaluate the effect of diabetes mellitus and of sildenafil citrate on female urethral function. Twenty nine female rats were divided into four groups: G1 - (n=9), normal rats; G2 - (n=6), normal rats treated with sildenafil citrate; G3 - (n=9) rats with alloxan-induced diabetes; G4 - (n=5) rats with alloxan-induced diabetes treated with sildenafil citrate. Under anesthesia, urodynamic evaluation was performed by cystometry and urethral pressure simultaneously. A significant increase in urethral pressure was observed during micturition. Sildenafil citrate can partially reduced urethral pressure in diabetic female rats.

Citrate-Based Biomaterials and Their Applications in Regenerative Engineering

PubMed Central

Tran, Richard T.; Yang, Jian; Ameer, Guillermo A.

2015-01-01

Advances in biomaterials science and engineering are crucial to translating regenerative engineering, an emerging field that aims to recreate complex tissues, into clinical practice. In this regard, citrate-based biomaterials have become an important tool owing to their versatile material and biological characteristics including unique antioxidant, antimicrobial, adhesive, and fluorescent properties. This review discusses fundamental design considerations, strategies to incorporate unique functionality, and examples of how citrate-based biomaterials can be an enabling technology for regenerative engineering. PMID:27004046

Interactions of citrate synthases from osmoconforming and osmoregulating animals with salt: possible signs of molecular eco-adaptation?

PubMed

Sarkissian, I V

1977-01-01

This study considers differential sensitivity of citrate synthase (citrate oxaloacetatelyase [CoA acetylating]) EC 4.1.3.7. from an osmoconforming animal (sea anemone) and an osmoregulating animal (the pig) to salt. Attention is drawn to the fact that the osmoconforming sea anemone is in essence a sessile creature while the pig is readily mobile and able to change its ionic environment at will. It had been shown earlier that citrate synthase from another osmoconformer (oyster) is also not sensitive to ionic strength while citrate synthase from osmoregulating white shrimp is sensitive to increasing levels of salt. However, these enzymes are characteristically regulated by ATP and alpha-ketoglutarate. Both forms of citrate synthase are denatured by 6 M guanidine hydrochloride and are aided by salt levels in their refolding but the rate and extent of refolding of the osmoconformer citrate synthase are greater than those of the osmoregulator citrate synthase. Catalytic activity of both forms of citrate synthase is inhibited by incubation in distilled water; osmoconformer citrate synthase was inhibited completely in 7 h while osmoregulator citrate synthase was inhibited only 60% in this time and 80% after 22 h in distilled water. The eco-adaptive and evolutionary implications of these findings are discussed.

SILDENAFIL CITRATE INDUCED RETINAL TOXICITY-ELECTRORETINOGRAM, OPTICAL COHERENCE TOMOGRAPHY, AND ADAPTIVE OPTICS FINDINGS.

PubMed

Yanoga, Fatoumata; Gentile, Ronald C; Chui, Toco Y P; Freund, K Bailey; Fell, Millie; Dolz-Marco, Rosa; Rosen, Richard B

2018-02-27

To report a case of persistent retinal toxicity associated with a high dose of sildenafil citrate intake. Single retrospective case report. A 31-year-old white man with no medical history presented with complaints of bilateral multicolored photopsias and erythropsia (red-tinted vision), shortly after taking sildenafil citrate-purchased through the internet. Patient was found to have cone photoreceptor damage, demonstrated using electroretinogram, optical coherence tomography, and adaptive optics imaging. The patient's symptoms and the photoreceptor structural changes persisted for several months. Sildenafil citrate is a widely used erectile dysfunction medication that is typically associated with transient visual symptoms in normal dosage. At high dosage, sildenafil citrate can lead to persistent retinal toxicity in certain individuals.

Studies on sildenafil citrate (Viagra) interaction with DNA using electrochemical DNA biosensor.

PubMed

Rauf, Sakandar; Nawaz, Haq; Akhtar, Kalsoom; Ghauri, Muhammad A; Khalid, Ahmad M

2007-05-15

The interaction of sildenafil citrate (Viagra) with DNA was studied by using an electrochemical DNA biosensor. The binding mechanism of sildenafil citrate was elucidated by using constant current potentiometry and differential pulse voltammetry at DNA-modified glassy carbon electrode. The decrease in the guanine oxidation peak area or peak current was used as an indicator for the interaction in 0.2M acetate buffer (pH 5). The binding constant (K) values obtained were 2.01+/-0.05 x 10(5) and 1.97+/-0.01 x 10(5)M(-1) with constant current potentiometry and differential pulse voltammetry, respectively. A linear dependence of the guanine peak area or peak current was observed within the range of 1-40 microM sildenafil citrate with slope=-2.74 x 10(-4)s/microM, r=0.989 and slope=-2.78 x 10(-3)microA/microM, r=0.995 by using constant current potentiometry and differential pulse voltammetry, respectively. Additionally, binding constant values for sildenafil citrate-DNA interaction were determined for the pH range of 4-8 and in biological fluids (serum and urine) at pH 5. The influence of sodium and calcium ions was also studied to elucidate the mechanism of sildenafil citrate-DNA interaction under different solution conditions. The present study may prove to be helpful in extending our understanding of the anticancer activity of sildenafil citrate from cellular to DNA level.

Films based on neutralized chitosan citrate as innovative composition for cosmetic application.

PubMed

Libio, Illen C; Demori, Renan; Ferrão, Marco F; Lionzo, Maria I Z; da Silveira, Nádya P

2016-10-01

In this work, citrate and acetate buffers, were investigated as neutralizers to chitosan salts in order to provide biocompatible and stable films. To choose the appropriate film composition for this study, neutralized chitosan citrate and acetate films, with and without the plasticizer glycerol, were prepared and characterized by thickness, moisture content, degree of swelling, total soluble matter in acid medium, simultaneous thermal analysis and differential scanning calorimetry. Chitosan films neutralized in citrate buffer showed greater physical integrity resulted from greater thicknesses, lower moisture absorbance, lower tendency to solubility in the acid medium, and better swelling capacities. According to thermal analyses, these films had higher interaction with water which is considered an important feature for cosmetic application. Since the composition prepared in citrate buffer without glycerol was considered to present better physical integrity, it was applied to investigate hyaluronic acid release in a skin model. Skins treated with those films, with or without hyaluronic acid, show stratum corneum desquamation and hydration within 10min. The results suggest that the neutralized chitosan citrate film prepared without glycerol promotes a cosmetic effect for skin exfoliation in the presence or absence of hyaluronic acid. Copyright © 2016 Elsevier B.V. All rights reserved.

76 FR 19997 - Determination That FENTORA (Fentanyl Citrate) Buccal Tablet, 300 Micrograms, Was Not Withdrawn...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-11

...] Determination That FENTORA (Fentanyl Citrate) Buccal Tablet, 300 Micrograms, Was Not Withdrawn From Sale for... Food and Drug Administration (FDA) has determined that FENTORA (fentanyl citrate) buccal tablet, 300... allow FDA to approve abbreviated new drug applications (ANDAs) for fentanyl citrate buccal tablet, 300...

Meta-analysis of letrozole versus clomiphene citrate in polycystic ovary syndrome.

PubMed

He, Donghong; Jiang, Fengyan

2011-07-01

The aim of this study was to systematically compare the clinical efficacy and safety of letrozole with clomiphene citrate for ovulation induction in women with polycystic ovary syndrome (PCOS). The Cochrane Central Register of Controlled Trials, PubMed, EMbase, CBMdisc and CNKI were searched for eligible randomized controlled trials (RCT) comparing letrozole with clomiphene citrate in PCOS patients. Two reviewers independently extracted information and evaluated methodological quality according to the Cochrane Handbook 5.0. Meta-analysis was performed with the fixed-effects model or random-effects model according to the heterogeneity. Six eligible RCT involving 841 patients were included. Letrozole was associated with a number of lower mature follicles per cycle (standardized mean difference (SMD) -1.41; 95% confidence intervales (CI) -1.54 to -1.28; P<0.00001) compared with clomiphene citrate. There were no significant differences in pregnancy rate (relative risk (RR) 0.97; 95% CI 0.79 to 1.18), abortion rate (RR 1.38; 95% CI 0.48 to -3.96) and multiple pregnancy rate (RR 0.34; 95% CI 0.07 to -1.72) between the two groups. The evidence from ovulation rates was not enough to support either letrozole or clomiphene citrate. In conclusion, letrozole is as effective as clomiphene citrate for ovulation induction in patients with PCOS. Copyright © 2011 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Nitrate Protects Cucumber Plants Against Fusarium oxysporum by Regulating Citrate Exudation.

PubMed

Wang, Min; Sun, Yuming; Gu, Zechen; Wang, Ruirui; Sun, Guomei; Zhu, Chen; Guo, Shiwei; Shen, Qirong

2016-09-01

Fusarium wilt causes severe yield losses in cash crops. Nitrogen plays a critical role in the management of plant disease; however, the regulating mechanism is poorly understood. Using biochemical, physiological, bioinformatic and transcriptome approaches, we analyzed how nitrogen forms regulate the interactions between cucumber plants and Fusarium oxysporum f. sp. cucumerinum (FOC). Nitrate significantly suppressed Fusarium wilt compared with ammonium in both pot and hydroponic experiments. Fewer FOC colonized the roots and stems under nitrate compared with ammonium supply. Cucumber grown with nitrate accumulated less fusaric acid (FA) after FOC infection and exhibited increased tolerance to chemical FA by decreasing FA absorption and transportation in shoots. A lower citrate concentration was observed in nitrate-grown cucumbers, which was associated with lower MATE (multidrug and toxin compound extrusion) family gene and citrate synthase (CS) gene expression, as well as lower CS activity. Citrate enhanced FOC spore germination and infection, and increased disease incidence and the FOC population in ammonium-treated plants. Our study provides evidence that nitrate protects cucumber plants against F. oxysporum by decreasing root citrate exudation and FOC infection. Citrate exudation is essential for regulating disease development of Fusarium wilt in cucumber plants. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Sildenafil citrate use in Addis Ababa: characteristics of users and pharmacists' dispensing practices.

PubMed

Gebregeorgise, Dawit Teshome; Belay, Yajeb Melesse; Kälvemark Sporrong, Sofia

2018-02-01

Background Studies have reported misuse of sildenafil citrate for recreational purpose, not least by healthy young men. This is becoming a major concern, for medical and other reasons. Objective The aim of this study was to document the characteristics of sildenafil citrate users and to explore the dispensing practices of the medicine in selected community pharmacies in Addis Ababa, Ethiopia. Setting Data was collected in community pharmacies in Addis Ababa, Ethiopia. Method A survey, using a self-administrated questionnaire, was conducted among customers who purchased sildenafil citrate from community pharmacies. Simple descriptive statistics were used to analyse data. Also, semi-structured interviews were conducted with community pharmacists. These were analysed thematically. Main outcome measures Socio-demographic characteristics (survey), themes (interviews). Results All survey respondents (n = 197) were men, 57.9% were below 40 years old, 53.8% had never been married and 58.4% had used sildenafil citrate before. A minority (16.2%) were diagnosed with erectile dysfunction. The main reason for buying sildenafil citrate was experimentation (45.7%). Pharmacists reported that sildenafil citrate was often dispensed without a prescription. The reason for this was, according to the interviewees, competition in the market. Also, the medicine was often dispensed without adequate information or counselling. Conclusions Selling and buying sildenafil citrate without a prescription seems to be common practice in pharmacies in Addis Ababa. It is crucial to strengthen the regulatory activity to protect customers from health risks. In addition pharmacy professionals should be supported to work in accordance with professional and legal standards.

Albumin Loss and Citrate Load in Pre-Dilution High Cut-Off-CVVHDF with Regional Citrate (18 mmol/L) and High Cut-Off CVVHD with Systemic Heparin: An in vitro Study.

PubMed

Villa, Gianluca; Neri, Mauro; De Rosa, Silvia; Samoni, Sara; Chelazzi, Cosimo; Romagnoli, Stefano; Lorenzin, Anna; de Cal, Massimo; Ronco, Claudio; De Gaudio, Angelo Raffaele

2018-06-08

Convective therapies with high cut-off membranes (HCO) are usually not recommended because of theoretical excessive albumin loss. The aim of this in vitro study is to demonstrate the noninferior safety of pre-dilution hemodiafiltration with HCO (HCO-CVVHDF) with isotonic citrate anticoagulation (18 mmol/L) with respect to heparin anticoagulated hemodialysis with HCO (HCO-CVVHD) in terms of albumin removal and citrate load. -Albumin removal was compared in vitro between 3 pre--dilution-HCO-CVVHDF with citrate anticoagulation and 3 -HCO-CVVHD with heparin anticoagulation during 30-min single-pass and 180-min recirculation phases. Considering concentrations and flows in the extracorporeal circuit, the transmembrane albumin removal was 2.06 (1.51; 2.09) g and 2.09 (1.9; 2.8) g respectively for HCO-CVVHDF and HCO-CVVHD, during the single-pass phase; 2.8 (2.67; 4.59) g and 2.54 (2.35; 4.67) g, respectively, for HCO-CVVHDF and HCO-CVVHD during the recirculation phase. Based on the citrate saturation coefficients, a citrate metabolic load of 8.86 mmol/h has been calculated for HCO-CVVHDF. HCO-CVVHDF performed with regional anticoagulation with 18 mmol/L citrate solution does not induce higher -albumin transmembrane removal compared to HCO-CVVHD. © 2018 S. Karger AG, Basel.

Occurrence of 1-glyceryl-1-myo-inosityl phosphate in hyperthermophiles.

PubMed

Lamosa, Pedro; Gonçalves, Luís G; Rodrigues, Marta V; Martins, Lígia O; Raven, Neil D H; Santos, Helena

2006-09-01

The accumulation of compatible solutes was studied in the hyperthermophilic bacterium Aquifex pyrophilus as a function of the temperature and the NaCl concentration of the growth medium. Nuclear magnetic resonance analysis of cell extracts revealed the presence of alpha- and beta-glutamate, di-mannosyl-di-myo-inositol phosphate, di-myo-inositol phosphate, and an additional compound here identified as 1-glyceryl-1-myo-inosityl phosphate. All solutes accumulated by A. pyrophilus are negatively charged at physiological pH. The intracellular levels of di-myo-inositol phosphate increased in response to supraoptimal growth temperature, while alpha- and beta-glutamate accumulated in response to osmotic stress, especially at growth temperatures below the optimum. The newly discovered compound, 1-glyceryl-1-myo-inosityl phosphate, appears to play a double role in osmo- and thermoprotection, since its intracellular pool increased primarily in response to a combination of osmotic and heat stresses. This work also uncovered the nature of the unknown compound, previously detected in Archaeoglobus fulgidus (L. O. Martins et al., Appl. Environ. Microbiol. 63:896-902, 1997). The curious structural relationship between diglycerol phosphate (found only in Archaeoglobus species), di-myo-inositol phosphate (a canonical solute of hyperthermophiles), and the newly identified solute is highlighted. This is the first report on the occurrence of 1-glyceryl-1-myo-inosityl phosphate in living systems.

Post-Dilution on Line Haemodiafiltration with Citrate Dialysate: First Clinical Experience in Chronic Dialysis Patients

PubMed Central

Panichi, Vincenzo; Fiaccadori, Enrico; Fanelli, Roberto; Bernabini, Giada; Pizzarelli, Francesco

2013-01-01

Background. Citrate has anticoagulative properties and favorable effects on inflammation, but it has the potential hazards of inducing hypocalcemia. Bicarbonate dialysate (BHD) replacing citrate for acetate is now used in chronic haemodialysis but has never been tested in postdilution online haemodiafiltration (OL-HDF). Methods. Thirteen chronic stable dialysis patients were enrolled in a pilot, short-term study. Patients underwent one week (3 dialysis sessions) of BHD with 0.8 mmol/L citrate dialysate, followed by one week of postdilution high volume OL-HDF with standard bicarbonate dialysate, and one week of high volume OL-HDF with 0.8 mmol/L citrate dialysate. Results. In citrate OL-HDF pretreatment plasma levels of C-reactive protein and β2-microglobulin were significantly reduced; intra-treatment plasma acetate levels increased in the former technique and decreased in the latter. During both citrate techniques (OL-HDF and HD) ionized calcium levels remained stable within the normal range. Conclusions. Should our promising results be confirmed in a long-term study on a wider population, then OL-HDF with citrate dialysate may represent a further step in improving dialysis biocompatibility. PMID:24367243

SbnG, a citrate synthase in Staphylococcus aureus: A new fold on an old enzyme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kobylarz, Marek J.; Grigg, Jason C.; Sheldon, Jessica R.

In response to iron deprivation, Staphylococcus aureus produces staphyloferrin B, a citrate-containing siderophore that delivers iron back to the cell. This bacterium also possesses a second citrate synthase, SbnG, that is necessary for supplying citrate to the staphyloferrin B biosynthetic pathway. In this paper, we present the structure of SbnG bound to the inhibitor calcium and an active site variant in complex with oxaloacetate. The overall fold of SbnG is structurally distinct from TCA cycle citrate synthases yet similar to metal-dependent class II aldolases. Phylogenetic analyses revealed that SbnG forms a separate clade with homologs from other siderophore biosynthetic genemore » clusters and is representative of a metal-independent subgroup in the phosphoenolpyruvate/pyruvate domain superfamily. Finally, a structural superposition of the SbnG active site to TCA cycle citrate synthases and site-directed mutagenesis suggests a case for convergent evolution toward a conserved catalytic mechanism for citrate production.« less

SbnG, a citrate synthase in Staphylococcus aureus: A new fold on an old enzyme

DOE PAGES

Kobylarz, Marek J.; Grigg, Jason C.; Sheldon, Jessica R.; ...

2014-10-21

In response to iron deprivation, Staphylococcus aureus produces staphyloferrin B, a citrate-containing siderophore that delivers iron back to the cell. This bacterium also possesses a second citrate synthase, SbnG, that is necessary for supplying citrate to the staphyloferrin B biosynthetic pathway. In this paper, we present the structure of SbnG bound to the inhibitor calcium and an active site variant in complex with oxaloacetate. The overall fold of SbnG is structurally distinct from TCA cycle citrate synthases yet similar to metal-dependent class II aldolases. Phylogenetic analyses revealed that SbnG forms a separate clade with homologs from other siderophore biosynthetic genemore » clusters and is representative of a metal-independent subgroup in the phosphoenolpyruvate/pyruvate domain superfamily. Finally, a structural superposition of the SbnG active site to TCA cycle citrate synthases and site-directed mutagenesis suggests a case for convergent evolution toward a conserved catalytic mechanism for citrate production.« less

SbnG, a citrate synthase in Staphylococcus aureus: a new fold on an old enzyme.

PubMed

Kobylarz, Marek J; Grigg, Jason C; Sheldon, Jessica R; Heinrichs, David E; Murphy, Michael E P

2014-12-05

In response to iron deprivation, Staphylococcus aureus produces staphyloferrin B, a citrate-containing siderophore that delivers iron back to the cell. This bacterium also possesses a second citrate synthase, SbnG, that is necessary for supplying citrate to the staphyloferrin B biosynthetic pathway. We present the structure of SbnG bound to the inhibitor calcium and an active site variant in complex with oxaloacetate. The overall fold of SbnG is structurally distinct from TCA cycle citrate synthases yet similar to metal-dependent class II aldolases. Phylogenetic analyses revealed that SbnG forms a separate clade with homologs from other siderophore biosynthetic gene clusters and is representative of a metal-independent subgroup in the phosphoenolpyruvate/pyruvate domain superfamily. A structural superposition of the SbnG active site to TCA cycle citrate synthases and site-directed mutagenesis suggests a case for convergent evolution toward a conserved catalytic mechanism for citrate production. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Stabilizing effect of citrate buffer on the photolysis of riboflavin in aqueous solution

PubMed Central

Ahmad, Iqbal; Sheraz, Muhammad Ali; Ahmed, Sofia; Kazi, Sadia Hafeez; Mirza, Tania; Aminuddin, Mohammad

2011-01-01

In the present investigation the photolysis of riboflavin (RF) in the presence of citrate species at pH 4.0–7.0 has been studied. A specific multicomponent spectrophotometric method has been used to assay RF in the presence of photoproducts during the reactions. The overall first-order rate constants (kobs) for the photolysis of RF range from 0.42 to 1.08×10–2 min−1 in the region. The values of kobs have been found to decrease with an increase in citrate concentration indicating an inhibitory effect of these species on the rate of reaction. The second-order rate constants for the interaction of RF with total citrate species causing inhibition range from 1.79 to 5.65×10–3 M−1 min−1 at pH 4.0–7.0. The log k–pH profiles for the reactions at 0.2–1.0 M citrate concentration show a gradual decrease in kobs and the value at 1.0 M is more than half compared to that of k0, i.e., in the absence of buffer, at pH 5.0. Divalent citrate ions cause a decrease in RF fluorescence due to the quenching of the excited singlet state resulting in a decrease in the rate of reaction and consequently leading to the stabilization of RF solutions. The greater quenching of fluorescence at pH 4.0 compared to that of 7.0 is in accordance with the greater concentration of divalent citrate ions (99.6%) at that pH. The trivalent citrate ions exert a greater inhibitory effect on the rate of RF photolysis compared to that of the divalent citrate ions probably as a result of excited triplet state quenching. The values of second-order rate constants for the interaction of divalent and trivalent citrate ions are 0.44×10–2 and 1.06×10–3 M–1 min–1, respectively, indicating that the trivalent ions exert a greater stabilizing effect, compared to the divalent ions, on RF solutions. PMID:25755977

Electrospray ionization of uranyl-citrate complexes

NASA Astrophysics Data System (ADS)

Somogyi, Árpád; Pasilis, Sofie P.; Pemberton, Jeanne E.

2007-09-01

Results presented here demonstrate the usefulness of electrospray ionization and gas-phase ion-molecule reactions to predict structural and electronic differences in complex inorganic ions. Electrospray ionization of uranyl citrate solutions generates positively and negatively charged ions that participate in further ion-molecule reactions in 3D ion trap and FT-ICR mass analyzers. Most ions observed are derived from the major solution uranyl-citrate complexes and involve species of {(UO2)2Cit2}2-, (UO2)3Cit2, and {(UO2)3Cit3}3-, where Cit indicates the citrate trianion, C6H5O73-. In a 3D ion trap operated at relatively high pressure, complex adducts containing solvent molecules, alkali and ammonium cations, and nitrate or chloride anions are dominant, and proton/alkali cation (Na+, K+) exchange is observed for up to six exchangeable protons in an excess of alkali cations. Adduct formation in a FT-ICR cell that is operated at lower pressures is less dominant, and direct detection of positive and negative ions of the major solution complexes is possible. Multiply charged ions are also detected, suggesting the presence of uranium in different oxidation states. Changes in uranium oxidation state are detected by He-CID and SORI-CID fragmentation, and certain fragments undergo association reactions in trapping analyzers, forming "exotic" species such as [(UO2)4O3]-, [(UO2)4O4]-, and [(UO2)4O5]-. Ion-molecule reactions with D2O in the FT-ICR cell indicate substantial differences in H/D exchange rate and D2O accommodation for different ion structures and charge states. Most notably, the positively charged ions [H2(UO2)2Cit2(H)]+ and [(UO2)2(Cit)]+ accommodate two and three D2O molecules, respectively, which reflects well the structural differences, i.e., tighter uranyl-citrate coordination in the former ion than in the latter. The corresponding negatively charged ions accommodate zero or two D2O molecules, which can be rationalized using suggested solution phase structures

Protective effects of sildenafil citrate administration on cisplatin-induced ovarian damage in rats.

PubMed

Taskin, Mine Islimye; Yay, Arzu; Adali, Ertan; Balcioglu, Esra; Inceboz, Umit

2015-04-01

The aim of this study is to evaluate the effects of sildenafil citrate on cisplatin-induced ovarian toxicity. Thirty-two female rats were divided into four groups. Group 1: saline control; group 2: cisplatin; group 3: sildenafil citrate; and group 4: cisplatin plus sildenafil citrate group. In groups 2 and 4, the rats were injected with 5 mg/kg cisplatin intraperitoneally (i.p.). In groups 3 and 4, the rats were injected with 1.4 mg/kg sildenafil citrate i.p. The ovaries were removed two weeks later in all groups. Histopathologic examination, follicle counting and classification were performed. The expression of anti-Müllerian hormone (AMH) was detected immunohistochemically in the ovarian tissues. Sildenafil alleviated cisplatin-induced histopathological changes in the ovarian tissue. Primordial, secondary and tertiary follicles were diminished in group 2 compared with group 1 (p < 0.05). Pretreatment with sildenafil citrate preserved primordial follicle count in group 4 compared with group 2, and the difference was statistically significant (p < 0.05). According to our results, immunoreactivity intensity of AMH was lower in group 2 compared with group 1 (92.4 ± 3.97 versus 88.8 ± 1.77) but not significantly, whereas immunoreactivity intensity of AMH was higher in group 4 compared with group 2 (88.8 ± 1.77 versus 94.1 ± 2.36; p < 0.05). Our results demonstrated that pretreatment with sildenafil citrate is beneficial for protecting the ovaries from cisplatin-induced damage. Sildenafil citrate can be a choice for fertility preservation.

77 FR 74171 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Final Results of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-13

... citric acid sodium salt, and the monohydrate and monopotassium forms of potassium citrate.\\5\\ Sodium... (``HTSUS''), respectively. Potassium citrate and crude calcium citrate are classifiable under 2918.15.5000... potassium citrate are classifiable under 3824.90.9290 of the HTSUS. Although the HTSUS subheadings are...

Effect of topically applied sildenafil citrate on wound healing: experimental study.

PubMed

Gürsoy, Koray; Oruç, Melike; Kankaya, Yüksel; Ulusoy, Mustafa Gürhan; Koçer, Uğur; Kankaya, Duygu; Gürsoy, Reyhan Neslihan; Çevik, Özge; Öğüş, Elmas; Fidanci, Vildan

2014-08-16

Wound healing is a complex process that necessitates organization of different cell types and several signalling molecules. The aim of this study is to evaluate the effect of different concentrations of sildenafil citrate, which decreases cGMP degradation, on wound healing by secondary intention.This study was performed using 25 Sprague Dawley rats weighing 200-250 grams. 4 dorsal defects were created. Four different treatment modalities which were 1% and 5% sildenafil citrate gel prepared with carbopol, pure carbopol gel without any drug in it and 0,9% NaCl solution; were applied to each lesion of the same rat. Randomly selected five rats (25 rats in total) were sacrificed on 3rd, 5th, 7th, 10th, and 14th days; and the effect of each modality was evaluated by means of defect area measurement, histopathological examination and measurement of tissue hydroxyproline levels.Sildenafil citrate gel application decreased the defect areas in a dose independent manner starting from 3rd day and dose dependent manner after 7th day. By means of vascularization, sildenafil citrate increased vascularity starting from 3rd day. The strength of acute inflammation was superior in sildenafil groups starting from 5th day; and the amount and maturation of granulation in the wound bed, as well as the strength of chronic inflammation were superior in defects treated with sildenafil citrate as early as 7th day.

Effect of topically applied sildenafil citrate on wound healing: experimental study

PubMed Central

Gürsoy, Koray; Oruç, Melike; Kankaya, Yüksel; Ulusoy, M. Gürhan; Koçer, Uğur; Kankaya, Duygu; Gürsoy, R. Neslihan; Çevik, Özge; Öğüş, Elmas; Fidanci, Vildan

2014-01-01

Wound healing is a complex process that necessitates organization of different cell types and several signalling molecules. The aim of this study is to evaluate the effect of different concentrations of sildenafil citrate, which decreases cGMP degradation, on wound healing by secondary intention. This study was performed using 25 Sprague Dawley rats weighing 200-250 grams. 4 dorsal defects were created. Four different treatment modalities which were 1% and 5% sildenafil citrate gel prepared with carbopol, pure carbopol gel without any drug in it and 0,9% NaCl solution; were applied to each lesion of the same rat. Randomly selected five rats (25 rats in total) were sacrificed on 3rd, 5th, 7th, 10th, and 14th days; and the effect of each modality was evaluated by means of defect area measurement, histopathological examination and measurement of tissue hydroxyproline levels. Sildenafil citrate gel application decreased the defect areas in a dose independent manner starting from 3rd day and dose dependent manner after 7th day. By means of vascularization, sildenafil citrate increased vascularity starting from 3rd day. The strength of acute inflammation was superior in sildenafil groups starting from 5th day; and the amount and maturation of granulation in the wound bed, as well as the strength of chronic inflammation were superior in defects treated with sildenafil citrate as early as 7th day. PMID:25172969

77 FR 56188 - Citric Acid and Certain Citrate Salts from the People's Republic of China: Notice of Rescission...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-12

... the order includes all grades and granulation sizes of citric acid, sodium citrate, and potassium... also includes blends of citric acid, sodium citrate, and potassium citrate; as well as blends with other ingredients, such as sugar, where the unblended form(s) of citric acid, sodium citrate, and...

Sensitive and selective SERS probe for trivalent chromium detection using citrate attached gold nanoparticles.

PubMed

Ye, Yingjie; Liu, Honglin; Yang, Liangbao; Liu, Jinhuai

2012-10-21

In this article, we have demonstrated a sensitive and selective surface enhanced Raman spectroscopy (SERS) probe, based on citrate-capped gold nanoparticles (AuNPs), for trivalent chromium (Cr(3+)) detection. After introducing Tween 20 to a solution of citrate-capped AuNPs, the as-prepared Tween 20/citrate-AuNP probe could recognize Cr(3+) at a 50 × 10(-9) M level in an aqueous medium at a pH of 6.0. Tween 20 can stabilize the citrate-capped AuNPs against conditions of high ionic strength. Due to the chelation between Cr(3+) and citrate ions, AuNPs undergo aggregation. As a result, it formed several hot spots and provided a significant enhancement of the Raman signal intensity through electromagnetic (EM) field enhancements. A detailed mechanism for tremendous SERS intensity change had been discussed. The selectivity of this system toward Cr(3+) was 400-fold, remarkably greater than other metal ions.

A Process-Based Model of TCA Cycle Functioning to Analyze Citrate Accumulation in Pre- and Post-Harvest Fruits.

PubMed

Etienne, Audrey; Génard, Michel; Bugaud, Christophe

2015-01-01

Citrate is one of the most important organic acids in many fruits and its concentration plays a critical role in organoleptic properties. The regulation of citrate accumulation throughout fruit development, and the origins of the phenotypic variability of the citrate concentration within fruit species remain to be clarified. In the present study, we developed a process-based model of citrate accumulation based on a simplified representation of the TCA cycle to predict citrate concentration in fruit pulp during the pre- and post-harvest stages. Banana fruit was taken as a reference because it has the particularity of having post-harvest ripening, during which citrate concentration undergoes substantial changes. The model was calibrated and validated on the two stages, using data sets from three contrasting cultivars in terms of citrate accumulation, and incorporated different fruit load, potassium supply, and harvest dates. The model predicted the pre and post-harvest dynamics of citrate concentration with fairly good accuracy for the three cultivars. The model suggested major differences in TCA cycle functioning among cultivars during post-harvest ripening of banana, and pointed to a potential role for NAD-malic enzyme and mitochondrial malate carriers in the genotypic variability of citrate concentration. The sensitivity of citrate accumulation to growth parameters and temperature differed among cultivars during post-harvest ripening. Finally, the model can be used as a conceptual basis to study citrate accumulation in fleshy fruits and may be a powerful tool to improve our understanding of fruit acidity.

Chemical Speciation Analysis of Sports Drinks by Acid-Base Titrimetry and Ion Chromatography: A Challenging Beverage Formulation Project

ERIC Educational Resources Information Center

Drossman, Howard

2007-01-01

Students have standardized a sodium hydroxide solution and analyzed commercially available sports drinks by titrimetric analysis of the triprotic citric acid, dihydrogen phosphate, and dihydrogen citrate and by ion chromatography for chloride, total phosphate and citrate. These experiments are interesting examples of analyzing real-world food and…

A Role for the Krebs Cycle Intermediate Citrate in Metabolic Reprogramming in Innate Immunity and Inflammation

PubMed Central

Williams, Niamh C.; O’Neill, Luke A. J.

2018-01-01

Metabolism in immune cells is no longer thought of as merely a process for adenosine triphosphate (ATP) production, biosynthesis, and catabolism. The reprogramming of metabolic pathways upon activation is also for the production of metabolites that can act as immune signaling molecules. Activated dendritic cells (DCs) and macrophages have an altered Krebs cycle, one consequence of which is the accumulation of both citrate and succinate. Citrate is exported from the mitochondria via the mitochondrial citrate- carrier. Cytosolic metabolism of citrate to acetyl-coenzyme A (acetyl-CoA) is important for both fatty-acid synthesis and protein acetylation, both of which have been linked to macrophage and DC activation. Citrate-derived itaconate has a direct antibacterial effect and also has been shown to act as an anti-inflammatory agent, inhibiting succinate dehydrogenase. These findings identify citrate as an important metabolite for macrophage and DC effector function. PMID:29459863

A Role for the Krebs Cycle Intermediate Citrate in Metabolic Reprogramming in Innate Immunity and Inflammation.

PubMed

Williams, Niamh C; O'Neill, Luke A J

2018-01-01

Metabolism in immune cells is no longer thought of as merely a process for adenosine triphosphate (ATP) production, biosynthesis, and catabolism. The reprogramming of metabolic pathways upon activation is also for the production of metabolites that can act as immune signaling molecules. Activated dendritic cells (DCs) and macrophages have an altered Krebs cycle, one consequence of which is the accumulation of both citrate and succinate. Citrate is exported from the mitochondria via the mitochondrial citrate- carrier. Cytosolic metabolism of citrate to acetyl-coenzyme A (acetyl-CoA) is important for both fatty-acid synthesis and protein acetylation, both of which have been linked to macrophage and DC activation. Citrate-derived itaconate has a direct antibacterial effect and also has been shown to act as an anti-inflammatory agent, inhibiting succinate dehydrogenase. These findings identify citrate as an important metabolite for macrophage and DC effector function.

An assessment of lifestyle modification versus medical treatment with clomiphene citrate, metformin, and clomiphene citrate-metformin in patients with polycystic ovary syndrome.

PubMed

Karimzadeh, Mohammad Ali; Javedani, Mojgan

2010-06-01

To compare the effect of clomiphene citrate, metformin, and lifestyle modification on treatment of patients with polycystic ovary syndrome (PCOS). Prospective randomized double-blind study. University-based infertility clinic and research center. Three hundred forty-three overweight infertile women with PCOS. The participating women were assigned to four groups: clomiphene (n = 90), metformin (n = 90), clomiphene + metformin (n = 88), and lifestyle modification (n = 75). The patients in each group received standardized dietary and exercise advice from a dietitian. The primary outcome variables were change in menstrual cycle, waist circumference measurements, endocrine parameters, and lipid profile. The main secondary outcome variable was clinical pregnancy rate. The clinical pregnancy rate was 12.2% in clomiphene group, 14.4% in metformin group, 14.8% in clomiphene + metformin group, and 20% in lifestyle modification group. Lifestyle modification group achieved a significant reduction in waist circumference, total androgen, and lipid profile. Lifestyle modification improves the lipid profile in PCOS patients. Therefore, lifestyle modification may be used as the first line of ovulation induction in PCOS patients. Copyright (c) 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Sodium citrate 4% versus heparin as a lock solution in hemodialysis patients with central venous catheters.

PubMed

Yon, Calantha K; Low, Chai L

2013-01-15

The effects of heparin versus sodium citrate 4% as a lock solution on catheter-related infections (CRIs), catheter patency, and hospitalizations in long-term hemodialysis patients with central venous catheters (CVCs) were compared. Data for patients receiving heparin lock solutions were collected from July 2008 to July 2009. Data on patients receiving sodium citrate 4% lock solution were collected from September 2009 through December 2010. Patients who were receiving the heparin lock solution who continued to have a CVC in September 2009 were transitioned from heparin to sodium citrate catheter 4% lock solution. New patients with CVCs placed after September 2009 received sodium citrate 4% without a period of using heparin lock solution. Pertinent information on patient medical history, bleeding or clotting events, infections, and hospitalization was collected. Data were collected retrospectively for the heparin group and prospectively for the sodium citrate group. Data were collected from 360 patient-months among 60 patients during the heparin treatment period and from 451 patient-months among 58 patients during the sodium citrate period. Thirty-three patients were common to both study groups. There were significantly more CRIs and CRIs per 1000 catheter-days in the heparin than the sodium citrate treatment group. Secondary outcomes of hospitalizations and catheter thrombosis were comparable. CRIs and thrombosis led to significantly more catheter exchanges or removals in the heparin group than the sodium citrate group. In patients with long-term hemodialysis catheters, a lock solution of sodium citrate 4% was associated with fewer CRIs and similar effectiveness when compared with heparin 5000 units/mL.

75 FR 14491 - Listing of Color Additives Exempt From Certification; Bismuth Citrate

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-26

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 73 [Docket No. FDA-2008-C-0098] Listing of Color Additives Exempt From Certification; Bismuth Citrate AGENCY: Food... amending the color additive regulations to increase the permitted use level of bismuth citrate as a color...

Optimalization of Poly(neutral red) Coated-wire Electrode for Determination of Citrate in Soft Drinks

PubMed Central

Broncová, Gabriela; Shishkanova, Tatiana V.; Krondak, Martin; Volf, Radko; Král, Vladimír

2008-01-01

This report presents an optimization of potentiometric measurements with citrate-selective electropolymerized poly(neutral red) electrodes. The optimal background electrolyte for these measurements is a TRIS buffer with nitrate at pH 8.5. The electrodes described here exhibit stable and reproducible near-Nernstian response to citrates with a low detection limit of 6 × 10-6 M. Electrodes polymerized from sulfuric acid and acetonitrile are compared in detail. Simple and sensitive method for quantification of citrate in real-life samples by potentiometry with poly(neutral red) electrodes are presented. Data from potentiometric measurements of citrate are compared with capillary electrophoresis. PMID:27879724

Concentration-dependent Sildenafil citrate (Viagra) effects on ROS production, energy status, and human sperm function.

PubMed

Sousa, Maria Inês; Amaral, Sandra; Tavares, Renata Santos; Paiva, Carla; Ramalho-Santos, João

2014-04-01

Literature regarding the effects of sildenafil citrate on sperm function remains controversial. In the present study, we specifically wanted to determine if mitochondrial dysfunction, namely membrane potential, reactive oxygen species production, and changes in energy content, are involved in in vitro sildenafil-induced alterations of human sperm function. Sperm samples of healthy men were incubated in the presence of 0.03, 0.3, and 3 μM sildenafil citrate in a phosphate buffered saline (PBS)-based medium for 2, 3, 12, and 24 hours. Sperm motility and viability were evaluated and mitochondrial function, i.e., mitochondrial membrane potential and mitochondrial superoxide production were assessed using flow-cytometry. Additionally, adenosine triphosphate (ATP) levels were determined by high performance liquid chromatography (HPLC) analysis. Results show a decrease in sperm motility correlated with the level of mitochondria-generated superoxide, without a visible effect on mitochondrial membrane potential or viability upon exposure to sildenafil. The effect on both motility and superoxide production was higher for the intermediate concentration of sildenafil (0.3 µM) indicating that the in vitro effects of sildenafil on human sperm do not vary linearly with drug concentration. Adenosine triphosphate levels also decreased following sildenafil exposure, but this decrease was only detected after a decrease in motility was already evident. These results suggest that along with the level of ATP and mitochondrial function other factors are involved in the early sildenafil-mediated decline in sperm motility. However, the further decrease in ATP levels and increase in mitochondria-generated reactive oxygen species after 24 hours of exposure might further contribute towards declining sperm motility.

Molecular characterization of microbial population dynamics during sildenafil citrate degradation.

PubMed

De Felice, Bruna; Argenziano, Carolina; Guida, Marco; Trifuoggi, Marco; Russo, Francesca; Condorelli, Valerio; Inglese, Mafalda

2009-02-01

Little is known about pharmaceutical and personal care products pollutants (PPCPs), but there is a growing interest in how they might impact the environment and microbial communities. The widespread use of Viagra (sildenafil citrate) has attracted great attention because of the high usage rate, the unpredictable disposal and the unknown potential effects on wildlife and the environment. Until now information regarding the impact of Viagra on microbial community in water environment has not been reported. In this research, for the first time, the genetic profile of the microbial community, developing in a Viagra polluted water environment, was evaluated by means of the 16S and 18S rRNA genes, for bacteria and fungi, respectively, amplified by polymerase chain reaction (PCR) and separated using the denaturing gradient gel electrophoresis (DGGE) technique. The DGGE results revealed a complex microbial community structure with most of the population persisting throughout the experimental period. DNA sequences from bands observed in the different denaturing gradient gel electrophoresis profiles exhibited the highest degree of identity to uncultured bacteria and fungi found previously mainly in polluted environmental and treating bioreactors. Biotransformation ability of sildenafil citrate by the microbial pool was studied and the capability of these microorganisms to detoxify a polluted water ecosystem was assessed. The bacterial and fungal population was able to degrade sildenafil citrate entirely. Additionally, assays conducted on Daphnia magna, algal growth inhibition assay and cell viability determination on HepG2 human cells showed that biotransformation products obtained from the bacterial growth was not toxic. The higher removal efficiency for sildenafil citrate and the lack of toxicity by the biotransformation products obtained showed that the microbial community identified here represented a composite population that might have biotechnological relevance to

21 CFR 181.29 - Stabilizers.

Code of Federal Regulations, 2014 CFR

2014-04-01

.... Ammonium citrate. Ammonium potassium hydrogen phosphate. Calcium glycerophosphate. Calcium phosphate.... Calcium stearate. Disodium hydrogen phosphate. Magnesium glycerophosphate. Magnesium stearate. Magnesium...

Closed circuit recovery of copper, lead and iron from electronic waste with citrate solutions.

PubMed

Torres, Robinson; Lapidus, Gretchen T

2017-02-01

An integral closed circuit hydrometallurgical process is presented for base metal recovery from electronic waste. The leaching medium consists of a sodium citrate solution, from which base metals are retrieved by direct electrowinning, and the barren solution is recycled back to the leaching stage. This leaching-electrowinning cycle was repeated four times. The redox properties of the fresh citrate solution, as well as the leach liquors, were characterized by cyclic voltammetry to determine adequate conditions for metal reduction, as well as to limit citrate degradation. The leaching efficiency of electronic waste, employing the same solution after four complete cycles was 71, 83 and 94% for copper, iron and lead, respectively, compared to the original leach with fresh citrate solution. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impact of using two dialyzers in parallel on phosphate clearance in hemodialysis patients: a randomized trial.

PubMed

Thompson, Stephanie; Manns, Braden; Lloyd, Anita; Hemmelgarn, Brenda; MacRae, Jennifer; Klarenbach, Scott; Unsworth, Larry; Courtney, Mark; Tonelli, Marcello

2017-05-01

Dietary restriction and phosphate binders are the main interventions used to manage hyperphosphatemia in people on hemodialysis, but have limited efficacy. Modifying conventional dialysis regimens to enhance phosphate clearance as an alternative approach remains relatively unstudied. This was a 10-week, 2-arm, randomized crossover study. Participants were prevalent dialysis patients ( n = 32) with consecutive serum phosphate levels >1.6 mmol/L and on stable doses of a phosphate binder. Following a 2-week run-in period, participants were randomized to initiate dialysis using two high flux dialyzers in parallel (blood flow ≥350 mL/min, dialysate flow 800 mL/min) or standard dialysis using one high flux dialyzer (blood flow ≥350 mL/min, dialysate flow of 800 mL/min). Each regimen was 3 weeks in duration. After a 2-week washout period, participants received the alternate regimen. The primary outcome was the mean difference in phosphate clearance by dialyzer strategy. Secondary outcomes were phosphate removal and pre-dialysis serum phosphate. Phosphate clearance for the double dialyzer strategy did not differ significantly from the single dialyzer strategy [mean difference 7.5 mL/min (95% confidence interval, 95% CI, -6.1, 21.0), P = 0.28]. There was no difference in total phosphate removal and pre-dialysis phosphate between the double and single dialyzer strategies [total phosphate removal mean difference -0.2 mmol (95% CI -4.1, 3.7), P = 0.93; pre-dialysis mean difference 0.01 mmol/L (95% CI -0.18, 0.21), P = 0.88]. There was no difference in the proportion of participants who experienced at least one episode of intradialytic hypotension (32 versus 47%, P = 0.13). A limitation of the study was frequent protocol deviations in the dialysis prescription. In this study, the use of two dialyzers in parallel did not increase phosphate clearance, phosphate removal or pre-dialysis serum phosphorus when compared with a standard dialysis treatment strategy. Future studies

Mitochondrial and Plasma Membrane Citrate Transporters: Discovery of Selective Inhibitors and Application to Structure/Function Analysis

PubMed Central

Sun, Jiakang; Aluvila, Sreevidya; Kotaria, Rusudan; Mayor, June A.; Walters, D. Eric; Kaplan, Ronald S.

2010-01-01

Cytoplasmic citrate is the prime carbon source for fatty acid, triacylglycerol, and cholesterol biosyntheses, and also regulates glucose metabolism via its allosteric inhibition of phosphofructokinase. It originates either via the efflux of citrate from the mitochondrial matrix on the inner membrane citrate transport protein (CTP) or via the influx of extracellular citrate on the plasma membrane citrate transporter (PMCT). Despite their common substrate, the two transport proteins share little sequence similarity and they transport citrate via fundamentally different mechanisms. We tested the ability of a set of previously identified CTP inhibitors, to inhibit the PMCT. We found that of the top 10 CTP inhibitors only one substantially inhibited the PMCT. Conversely, we identified two other inhibitors that inhibited the PMCT but had little effect on the CTP. All three identified PMCT inhibitors displayed a noncompetitive mechanism. Furthermore, models to explain inhibitor interactions with the CTP are proposed. As part of the present studies a PMCT homology model has been developed based on the crystal structure of the leucine transporter, and a possible citrate binding site has been identified and its composition compared with the two known citrate binding sites present within the CTP. The ability to selectively inhibit the PMCT may prove key to the pharmacologic amelioration of metabolic disorders resulting from the synthesis of excess lipid, cholesterol, and glucose, including human obesity, hyperlipidemia, hyper-cholesterolemia, and Type 2 diabetes. PMID:20686672

3-Bromopyruvate antagonizes effects of lactate and pyruvate, synergizes with citrate and exerts novel anti-glioma effects.

PubMed

El Sayed, S M; El-Magd, R M Abou; Shishido, Y; Chung, S P; Diem, T H; Sakai, T; Watanabe, H; Kagami, S; Fukui, K

2012-02-01

Oxidative stress-energy depletion therapy using oxidative stress induced by D-amino acid oxidase (DAO) and energy depletion induced by 3-bromopyruvate (3BP) was reported recently (El Sayed et al., Cancer Gene Ther., 19, 1-18, 2012). Even in the presence of oxygen, cancer cells oxidize glucose preferentially to produce lactate (Warburg effect) which seems vital for cancer microenvironment and progression. 3BP is a closely related structure to lactate and pyruvate and may antagonize their effects as a novel mechanism of its action. Pyruvate exerted a potent H(2)O(2) scavenging effect to exogenous H(2)O(2), while lactate had no scavenging effect. 3BP induced H(2)O(2) production. Pyruvate protected against H(2)O(2)-induced C6 glioma cell death, 3BP-induced C6 glioma cell death but not against DAO/D-serine-induced cell death, while lactate had no protecting effect. Lactate and pyruvate protected against 3BP-induced C6 glioma cell death and energy depletion which were overcome with higher doses of 3BP. Lactate and pyruvate enhanced migratory power of C6 glioma which was blocked by 3BP. Pyruvate and lactate did not protect against C6 glioma cell death induced by other glycolytic inhibitors e.g. citrate (inhibitor of phosphofructokinase) and sodium fluoride (inhibitor of enolase). Serial doses of 3BP were synergistic with citrate in decreasing viability of C6 glioma cells and spheroids. Glycolysis subjected to double inhibition using 3BP with citrate depleted ATP, clonogenic power and migratory power of C6 glioma cells. 3BP induced a caspase-dependent cell death in C6 glioma. 3BP was powerful in decreasing viability of human glioblastoma multiforme cells (U373MG) and C6 glioma in a dose- and time-dependent manner.

21 CFR 184.1911 - Triethyl citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Academy Press, 2101 Constitution Ave. NW., Washington, DC 20418, and the Center for Food Safety and... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Triethyl citrate. 184.1911 Section 184.1911 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

Sildenafil citrate monohydrate-cyclodextrin nanosuspension complexes for use in metered-dose inhalers.

PubMed

Sawatdee, Somchai; Phetmung, Hirihattaya; Srichana, Teerapol

2013-10-15

Sildenafil is a selective phosphodiesterase-5 inhibitor used for the treatment of erectile dysfunction and pulmonary hypertension. Sildenafil citrate monohydrate was complexed with α-, hydroxypropyl-β- and γ-cyclodextrin (α-CD, HP-β-CD and γ-CD, respectively) to enhance its water solubility. The complexes of sildenafil citrate monohydrate with all types of CDs were characterized by phase solubility diagrams, (1)H and (13)C NMR, and dielectric constants. Sildenafil citrate monohydrate complexed with CDs was developed as nanosuspensions for use in a pressurized metered-dose inhaler (pMDI). Sildenafil citrate monohydrate pMDI formulations were prepared by a bottom-up process using dried ethanol as a solvent and HFA-134a as an antisolvent and propellant in order to form nanosuspensions. A 3×3 factorial design was applied for the contents of the dried ethanol and HFA-134a propellant. The phase solubility profiles of the sildenafil and cyclodextrins were described as AL type with a mole ratio 1:1. The piperazine moiety of sildenafil formed an inclusion in the cavity of the CDs. The particle diameters of the sildenafil citrate monohydrate suspensions in pMDIs were all within a nanosuspension size range. An assay of the sildenafil content showed that the formation of complexes with CDs was close to 100%. In the case of the formulations with CDs, the emitted doses varied within 97.4±10.8%, the fine particle fractions (FPFs) were in a range of 45-81%, the fine particle dose (FPD) was 12.6±2.0 μg and the mass median aerodynamic diameters (MMADs) were 1.86±0.41 μm. In contrast, the formulations without CDs produced a low emitted dose of sildenafil (<60%). Therefore, only sildenafil citrate monohydrate pMDI formulations containing CDs were suitable for use as aerosols. Copyright © 2013 Elsevier B.V. All rights reserved.

[Efficacy of alverina citrate and simethicone combination in abdominal pain and discomfort of irritable bowel syndrome].

PubMed

Wittmann, T; Paradovsky, L; Ducrotte, P; Bueno, L; Andro-Delestrain, M C T

2011-01-01

The alverina citrate and simethicone combination (ACS-Meteospazmil) is used for irritable bowel syndrome (IBS) for almost 20 years, but the supporting scientific evidence for efficacy is limited. to evaluate the effectiveness of ACS in patients with abdominal pain and discomfort at IBS. In a double-blind, randomized, placebo-controlled study enrolled 412 patients with IBS conform to Rome criteria III. Selection criterion in the study was to evaluate the intensity of abdominal pain or discomfort during the 2-week run-in period without medication, which according to analog scale (VAS) was to be 60-100 mm. With the help of an interactive voice communication system (IVCS), patients were randomized to treatment with either alverin citrate 60 mg with Simethicone 300 mg three times daily or corresponding placebo for 4 weeks. For analyze of the results of the study were selected 409 patients. After 4 weeks, patients treated with ACS, was observed lower scores in the VAS assessment of abdominal pain or discomfort compared to placebo (mean--40 and 50 mm, p = 0.047) and a higher level of response to treatment (46.8% and 34.3%, respectively). Recorded side effects were similar in both groups. The combination of ACS was significantly more effective in patients with IBS compared to placebo in reducing abdominal pain or discomfort.

Free Rhodium (II) citrate and rhodium (II) citrate magnetic carriers as potential strategies for breast cancer therapy

PubMed Central

2011-01-01

Background Rhodium (II) citrate (Rh2(H2cit)4) has significant antitumor, cytotoxic, and cytostatic activity on Ehrlich ascite tumor. Although toxic to normal cells, its lower toxicity when compared to carboxylate analogues of rhodium (II) indicates Rh2(H2cit)4 as a promising agent for chemotherapy. Nevertheless, few studies have been performed to explore this potential. Superparamagnetic particles of iron oxide (SPIOs) represent an attractive platform as carriers in drug delivery systems (DDS) because they can present greater specificity to tumor cells than normal cells. Thus, the association between Rh2(H2cit)4 and SPIOs can represent a strategy to enhance the former's therapeutic action. In this work, we report the cytotoxicity of free rhodium (II) citrate (Rh2(H2cit)4) and rhodium (II) citrate-loaded maghemite nanoparticles or magnetoliposomes, used as drug delivery systems, on both normal and carcinoma breast cell cultures. Results Treatment with free Rh2(H2cit)4 induced cytotoxicity that was dependent on dose, time, and cell line. The IC50 values showed that this effect was more intense on breast normal cells (MCF-10A) than on breast carcinoma cells (MCF-7 and 4T1). However, the treatment with 50 μM Rh2(H2cit)4-loaded maghemite nanoparticles (Magh-Rh2(H2cit)4) and Rh2(H2cit)4-loaded magnetoliposomes (Lip-Magh-Rh2(H2cit)4) induced a higher cytotoxicity on MCF-7 and 4T1 than on MCF-10A (p < 0.05). These treatments enhanced cytotoxicity up to 4.6 times. These cytotoxic effects, induced by free Rh2(H2cit)4, were evidenced by morphological alterations such as nuclear fragmentation, membrane blebbing and phosphatidylserine exposure, reduction of actin filaments, mitochondrial condensation and an increase in number of vacuoles, suggesting that Rh2(H2cit)4 induces cell death by apoptosis. Conclusions The treatment with rhodium (II) citrate-loaded maghemite nanoparticles and magnetoliposomes induced more specific cytotoxicity on breast carcinoma cells than on breast

21 CFR 172.832 - Monoglyceride citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Monoglyceride citrate. A food additive that is a mixture of glyceryl monooleate and its citric acid monoester manufactured by the reaction of glyceryl monooleate with citric acid under controlled conditions may be safely..., 70-100. Total citric acid (free and combined), 14 percent-17 percent. (b) It is used, or intended for...

Synthesis of citrate from phosphoenolpyruvate and acetylcarnitine by mitochondria from rabbit, pigeon and rat liver: implications for lipogenesis.

PubMed

Wiese, T J; Wuensch, S A; Ray, P D

1996-08-01

Rabbit, pigeon and rat liver mitochondria convert exogenous phosphoenolpyruvate and acetylcarnitine to citrate at rates of 14, 74 and 8 nmol/15 min/mg protein. Citrate formation is dependent on exogenous HCO3-, is increased consistently by exogenous nucleotides (GDP, IDP, GTP, ADP, ATP) and inhibited strongly by 3-mercaptopicolinate and 1,2,3-benzenetricarboxylate. Citrate is not made from pyruvate alone or combined with acetylcarnitine. Pigeon and rat liver mitochondria make large amounts of citrate from exogenous succinate, suggesting the presence of an endogenous source of acetyl units or means of converting oxalacetate to acetyl units. Citrate synthesis from succinate by pigeon and rabbit mitochondria is increased significantly by exogenous acetylcarnitine. Pigeon and rat liver contain 80 and 15 times, respectively, more ATP:citrate lyase activity than does rabbit liver. Data suggest that mitochondrial phosphoenolpyruvate carboxykinase in vivo could convert glycolysis-derived phosphoenolpyruvate to oxalacetate that, with acetyl CoA, could form citrate for export to support cytosolic lipogenesis as an activator of acetyl CoA carboxylase, a carbon source via ATP:citrate lyase and NADPH via NADP:malate dehydrogenase or NADP:isocitrate dehydrogenase.

Ferric Citrate Reduces Intravenous Iron and Erythropoiesis-Stimulating Agent Use in ESRD

PubMed Central

Jalal, Diana I.; Greco, Barbara A.; Umeukeje, Ebele M.; Reisin, Efrain; Manley, John; Zeig, Steven; Negoi, Dana G.; Hiremath, Anand N.; Blumenthal, Samuel S.; Sika, Mohammed; Niecestro, Robert; Koury, Mark J.; Ma, Khe-Ni; Greene, Tom; Lewis, Julia B.; Dwyer, Jamie P.

2015-01-01

Ferric citrate (FC) is a phosphate binder with shown efficacy and additional effects on iron stores and use of intravenous (iv) iron and erythropoiesis-stimulating agents (ESAs). We provide detailed analyses of changes in iron/hematologic parameters and iv iron/ESA use at time points throughout the active control period of a phase 3 international randomized clinical trial. In all, 441 subjects were randomized (292 to FC and 149 to sevelamer carbonate and/or calcium acetate [active control (AC)]) and followed for 52 weeks. Subjects on FC had increased ferritin and transferrin saturation (TSAT) levels compared with subjects on AC by week 12 (change in ferritin, 114.1±29.35 ng/ml; P<0.001; change in TSAT, 8.62%±1.57%; P<0.001). Change in TSAT plateaued at this point, whereas change in ferritin increased through week 24, remaining relatively stable thereafter. Subjects on FC needed less iv iron compared with subjects on AC over 52 weeks (median [interquartile range] dose=12.9 [1.0–28.9] versus 26.8 [13.4–47.6] mg/wk; P<0.001), and the percentage of subjects not requiring iv iron was higher with FC (P<0.001). Cumulative ESA over 52 weeks was lower with FC than AC (median [interquartile range] dose=5303 [2023–9695] versus 6954 [2664–12,375] units/wk; P=0.04). Overall, 90.3% of subjects on FC and 89.3% of subjects on AC experienced adverse events. In conclusion, treatment with FC as a phosphate binder results in increased iron parameters apparent after 12 weeks and reduces iv iron and ESA use while maintaining hemoglobin over 52 weeks, with a safety profile similar to that of available binders. PMID:25736045

21 CFR 172.370 - Iron-choline citrate complex.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline...

21 CFR 172.370 - Iron-choline citrate complex.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline...

Enrofloxacinium citrate monohydrate: Preparation, crystal structure, thermal stability and IR-characterization

NASA Astrophysics Data System (ADS)

Golovnev, Nicolay N.; Vasiliev, Alexander D.; Kirik, Sergei D.

2012-08-01

Enrofloxacinium citrate monohydrate (I), CHFNO3+·CHO7-·HO, [C19H22FN3O3 - enrofloxacin, EnrH] has been crystallized from the mutual solution of citric acid and enrofloxacin in ambient conditions. The colorless crystals have been investigated using X-ray single crystal and powder techniques, and characterized by differential scanning calorimetry, thermogravimetry and infrared spectroscopy. The obtained compound can be considered as a salt with enrofloxacinium in the role of a cation and citrate as an anion. The ions ratio equals to 1:1. The compound crystallizes in the triclinic lattice with a = 9.0489(8) Å, b = 9.6531(8) Å, c = 14.913(1) Å, α = 98.813(1)°, β = 92.029(1)°, γ = 91.013(1)°, Z = 2, V = 1286.1(2) Å3, S.G. P1¯. The crystal structure determination reveals the importance of inter- and intramolecular interactions in the crystal formation. The EnrH2+ and HCit molecular ions are packed in alternating layers with water molecules inserted into the citrate layers. A citrate ion in the layer is linked via H-bondings with two adjacent ones and three water molecules. Enrofloxacinium cations are packaged by means of a benched mode and every cation is linked by three intermolecular thymus type H-bondings with nitrogens of adjacent cations and by two links with the oxygen of the citrate ions. The infrared spectra gave the evidence of H-bonding formation in the obtained salt. The π-stacking interactions are observed between the aromatic cycles of the adjacent cations which are located in an antiparallel style in a layer.

THE PREGNANCY IN POLYCYSTIC OVARY SYNDROME II (PPCOS II) TRIAL: RATIONALE AND DESIGN OF A DOUBLE-BLIND RANDOMIZED TRIAL OF CLOMIPHENE CITRATE AND LETROZOLE FOR THE TREATMENT OF INFERTILITY IN WOMEN WITH POLYCYSTIC OVARY SYNDROME

PubMed Central

Legro, Richard S.; Kunselman, Allen R.; Brzyski, Robert G.; Casson, Peter R.; Diamond, Michael P.; Schlaff, William D.; Christman, Gregory M.; Coutifaris, Christos; Taylor, Hugh S.; Eisenberg, Esther; Santoro, Nanette; Zhang, Heping

2012-01-01

Polycystic Ovary Syndrome (PCOS) is a common cause of female infertility and first line treatment is currently oral clomiphene citrate, a selective estrogen receptor modulator, which results in both a high nonresponse rate and multiple pregnancy rate. Aromatase inhibitors such as letrozole may have more favorable ovarian and endometrial effects. The goal of the Pregnancy in Polycystic Ovary Syndrome II (PPCOSII) study is to determine the safety and efficacy of clomiphene citrate (CC) compared to letrozole, in achieving live birth in infertile women with PCOS. The population will consist of 750 infertile women with PCOS. Additionally, the couple will have no other major infertility factor. This will be a multi-center, prospective, double-blind clinical trial of CC vs. letrozole for 5 treatment cycles (or approximately up to 25 weeks). The randomization scheme will be coordinated through the central data coordinating center (DCC) and the randomization is stratified by each participating site. After progestin withdrawal as needed, 750 women will be equally randomized to two different treatment arms: A) CC 50 mg every day for 5 days (day 3–7 of cycle), or B) letrozole 2.5 mg every day for 5 days (day 3–7 of cycle), for a total of 5 cycles or 25 weeks. The dose will be increased in subsequent cycles in both treatment groups for non-response or poor ovulatory response up to a maximum of 150 mg of CC a day (× 5 days) or 7.5 mg of letrozole a day (× 5 days). The primary analysis will use an intent-to-treat approach to examine differences in the live birth rate in the two treatment arms. PMID:22265923

Tunable Manipulation of Mineral Carbonation Kinetics in Nanoscale Water Films via Citrate Additives.

PubMed

Miller, Quin R S; Schaef, Herbert T; Kaszuba, John P; Qiu, Lin; Bowden, Mark E; McGrail, Bernard P

2018-06-06

We explored the influence of a model organic ligand on mineral carbonation in nanoscale interfacial water films by conducting five time-resolved in situ X-ray diffraction (XRD) experiments at 50 °C. Forsterite was exposed to water-saturated supercritical carbon dioxide (90 bar) that had been equilibrated with 0-0.5 m citrate (C 6 H 5 O 7 -3 ) solutions. The experimental results demonstrated that greater concentrations of citrate in the nanoscale interfacial water film promoted the precipitation of magnesite (MgCO 3 ) relative to nesquehonite (MgCO 3 ·3H 2 O). At the highest concentrations tested, magnesite nucleation and growth were inhibited, lowering the carbonation rate constant from 9.1 × 10 -6 to 3.6 × 10 -6 s -1 . These impacts of citrate were due to partial dehydration of Mg 2+ (aq) and the adsorption of citrate onto nuclei and magnesite surfaces. This type of information may be used to predict and tailor subsurface mineralization rates and pathways.

Diameter and location control of ZnO nanowires using electrodeposition and sodium citrate

NASA Astrophysics Data System (ADS)

Lifson, Max L.; Levey, Christopher G.; Gibson, Ursula J.

2013-10-01

We report single-step growth of spatially localized ZnO nanowires of controlled diameter to enable improved performance of piezoelectric devices such as nanogenerators. This study is the first to demonstrate the combination of electrodeposition with zinc nitrate and sodium citrate in the growth solution. Electrodeposition through a thermally-grown silicon oxide mask results in localization, while the growth voltage and solution chemistry are tuned to control the nanowire geometry. We observe a competition between lateral (relative to the (0001) axis) citrate-related morphology and voltage-driven vertical growth which enables this control. High aspect ratios result with either pure nitrate or nitrate-citrate mixtures if large voltages are used, but low growth voltages permit the growth of large diameter nanowires in solution with citrate. Measurements of the current density suggest a two-step growth process. An oxide mask blocks the electrodeposition, and suppresses nucleation of thermally driven growth, permitting single-step lithography on low cost p-type silicon substrates.

Oxidative status and citrate concentration in rat tissues during experimental hyperthyroidism and melatonin treatment.

PubMed

Popov, S S; Pashkov, A N; Popova, T N; Zoloedov, V I; Semenikhina, A V; Rakhmanova, T I

2007-08-01

Biochemiluminescence increased, while aconitate hydratase activity and citrate accumulation in tissues of the liver and heart and blood decreased in rats with experimental hyperthyroidism. These changes reflect activation of free radical oxidation, damage to enzyme molecules with reactive oxygen species, and impaired utilization of citrate under pathological conditions. Melatonin treatment during hyperthyroidism normalized aconitate hydratase activity and citrate concentration. Biochemiluminescence study showed that the effect of melatonin is related to antioxidant activity of this hormone, inhibition of free radical oxidation, and suppression of reactive oxygen species generation.

Effect of phosphate supplementation on oxygen delivery at high altitude

NASA Astrophysics Data System (ADS)

Jain, S. C.; Singh, M. V.; Rawal, S. B.; Sharma, V. M.; Divekar, H. M.; Tyagi, A. K.; Panwar, M. R.; Swamy, Y. V.

1987-09-01

In the present communication, effect of low doses of phosphate supplementation on short-term high altitude adaptation has been examined. Studies were carried out in 36 healthy, male, sea-level residents divided in a double blind fashion into drug and placebo treated groups. 3.2 mmol of phosphate were given orally to each subject of the drug treated group once a day for 4 days on arrival at an altitude of 3,500 m. Sequential studies were done in the subjects in both groups on the 3rd, 7th, 14th and 21st day of their altitude stay. Haemoglobin, haematocrit, erythrocyte and reticulocyte counts increased to the similar extent in both groups. Blood pH, pO2 and adenosine tri-phosphate (ATP) did not differ between the two groups. On 3rd day of the altitude stay, inorganic phosphate and 2,3-diphosphoglycerate (2,3 DPG) levels in the drug treated group increased significantly as compared to the placebo group. No significant difference in inorganic phosphate and 2,3 DPG was observed later on in the two groups. Psychological and clinical tests also indicated that the drug treated subjects felt better as compared to the placebo treated subjects. The present study suggests that low doses of phosphate increases circulating 2,3-DPG concentration which in turn brings about beneficial effect towards short term high altitude adaptation.

Rôle modeste du citrate comme transporteur d'acétyl-CoA chez l'animal vivant.

PubMed

Rous, S

1971-02-09

2,4-(14) C-Citrate incorporated to a far greater extent than 1,5-(14) C-citrate into liver, carcass or adipose tissue fatty acids of living mice. This finding excludes the possibility that the acetyl units emerge from the mitochondria in the form of citrate.

Impact of phosphate limitation on PHA production in a feast-famine process.

PubMed

Korkakaki, Emmanouela; van Loosdrecht, Mark C M; Kleerebezem, Robbert

2017-12-01

Double-limitation systems have shown to induce polyhydroxyalkanoates (PHA) production in chemostat studies limited in e.g. carbon and phosphate. In this work the impact of double substrate limitation on the enrichment of a PHA producing community was studied in a sequencing batch process. Enrichments at different C/P concentration ratios in the influent were established and the effect on the PHA production capacity and the enrichment community structure was investigated. Experimental results demonstrated that when a double substrate limitation is imposed at a C/P ratio in the influent in a range of 150 (C-mol/mol), the P-content of the biomass and the specific substrate uptake rates decreased. Nonetheless, the PHA storage capacity remained high (with a maximum of 84 wt%). At a C/P ratio of 300, competition in the microbial community is based on phosphate uptake, and the PHA production capacity is lost. Biomass specific substrate uptake rates are a linear function of the cellular P-content, offering advantages for scaling-up the PHA production process due to lower oxygen requirements. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dose-dependent protective effect of sildenafil citrate on testicular injury after torsion/detorsion in rats.

PubMed

Yıldız, H; Durmus, A S; Şimşek, H; Yaman, M

2012-05-01

This experiment was designed to investigate the effect of sildenafil citrate on testicular injury after unilateral testicular torsion/detorsion (T/D). Thirty-seven adult male Wistar albino rats were divided into four groups: sham operated group (group 1), T/D+ saline (group 2), T/D+ 0.7 mg sildenafil citrate (group 3) and T/D+ 1.4 mg sildenafil citrate (group 4). Testicular torsion was created by rotating the right testis 720° in a clockwise direction for 2 h in other groups, except for group 1, which was served as sham group. The level of GSH (P < 0.05) in the testis in the group 2 were significantly lower (P < 0.05) and the levels of MDA and NO (P < 0.01 for both) in the testis were significantly higher when compared with those of the group 1. Administration of low dose sildenafil citrate prevented the increases in MDA and NO levels and decreases in GSH values induced by testicular torsion. However, administration of high dose sildenafil citrate did not have any effect on these testicular tissue parameters (P > 0.05). Also, mean values of seminiferous tubules diameters, germinal cell layer thicknesses and mean testicular biopsy score were significantly better in group 3 than groups 2 and 4. These results suggest that T/D injury occurred in testis after unilateral testicular T/D and that administration of low dose sildenafil citrate before detorsion prevents ischemia/reperfusion cellular damage in testicular torsion. Sildenafil citrate probably acts through reduction of reactive oxygen species and support antioxidant enzyme systems. © 2011 Blackwell Verlag GmbH.

Influence of temperature on flavour compound production from citrate by Lactobacillus rhamnosus ATCC 7469.

PubMed

De Figueroa, R M; Oliver, G; Benito de Cárdenas, I L

2001-03-01

The citrate utilization by Lactobacillus rhamnosus ATCC 7469 was found to be temperature-dependent. The maximum citrate utilization and incorporation of [1,5-14C]citrate rate were observed at 37 degreesC. At this temperature, maximum citrate lyase activity and specific diacetyl and acetoin production (Y(DA%)) were observed. The high levels of alpha-acetolactate synthase and low levels of diacetyl reductase, acetoin reductase and L-lactate dehydrogenase found at 37 degreesC led to an accumulation of diacetyl and acetoin. Optimum lactic acid production was observed at 45 degreesC, according to the high lactate dehydrogenase activity. The NADH oxidase activity increased with increasing culture temperature from 22 degreesC to 37 degreesC. Thus there are greater quantities of pyruvate available for the production of alpha-acetolactate, diacetyl and aceotin, and less diacetyl and acetoin are reduced.

Antitumor effect of free rhodium (II) citrate and rhodium (II) citrate-loaded maghemite nanoparticles on mice bearing breast cancer: a systemic toxicity assay.

PubMed

Peixoto, Raphael Cândido Apolinário; Miranda-Vilela, Ana Luisa; de Souza Filho, José; Carneiro, Marcella Lemos' Brettas; Oliveira, Ricardo G S; da Silva, Matheus Oliveira; de Souza, Aparecido R; Báo, Sônia Nair

2015-05-01

Breast cancer is one of the most prevalent cancer types among women. The use of magnetic fluids for specific delivery of drugs represents an attractive platform for chemotherapy. In our previous studies, it was demonstrated that maghemite nanoparticles coated with rhodium (II) citrate (Magh-Rh2Cit) induced in vitro cytotoxicity and in vivo antitumor activity, followed by intratumoral administration in breast carcinoma cells. In this study, our aim was to follow intravenous treatment to evaluate the systemic antitumor activity and toxicity induced by these formulations in Balb/c mice bearing orthotopic 4T1 breast carcinoma. Female Balb/c mice were evaluated with regard to toxicity of intravenous treatments through analyses of hemogram, serum levels of alanine aminotransferase, iron, and creatinine and liver, kidney, and lung histology. The antitumor activity of rhodium (II) citrate (Rh2Cit), Magh-Rh2Cit, and maghemite nanoparticles coated with citrate (Magh-Cit), used as control, was evaluated by tumor volume reduction, histology, and morphometric analysis. Magh-Rh2Cit and Magh-Cit promoted a significant decrease in tumor area, and no experimental groups presented hematotoxic effects or increased levels of serum ALT and creatinine. This observation was corroborated by the histopathological examination of the liver and kidney of mice. Furthermore, the presence of nanoparticles was verified in lung tissue with no morphological changes, supporting the idea that our nanoformulations did not induce toxicity effects. No studies about the systemic action of rhodium (II) citrate-loaded maghemite nanoparticles have been carried out, making this report a suitable starting point for exploring the therapeutic potential of these compounds in treating breast cancer.

Restoration of blood 2,3-diphosphoglycerate levels in multi-transfused patients: effect of organic and inorganic phosphate.

PubMed

Iapichino, G; Radrizzani, D; Solca, M; Franzosi, M G; Pallavicini, F B; Spina, G; Scherini, A

1984-01-01

Blood stored in acid-citrate-dextrose (ACD) shows a progressive decrease in 2,3-diphosphoglycerate (DPG) content. Since the decrease in DPG increases hemoglobin oxygen affinity, which in turn may reduce tissue and venous PO2 and peripheral oxygen delivery, many efforts have been made to preserve or restore DPG levels in stored blood. An in vivo rejuvenating technique, employing fructose-1,6-diphosphate (FDP) at a mean dosage of 1 mmol kg-1 day-1 of phosphate, to increase the DPG circulating level in multi-transfused patients is proposed. Eighteen patients, who received at least one-third of their estimated blood volume (3990 +/- 480 (SEM) ml of ACD stored blood) in blood transfusion, were treated: nine with inorganic phosphate, and nine with FDP. Basal DPG was very low in both groups: 12.61 +/- 1.34 (SEM) and 10.42 +/- 0.98 (SEM) mumol g-1, respectively (normal value is 14.5 mumol g-1, at pH 7.40). However, DPG values increased significantly and promptly in patients receiving FDP, whereas in cases of inorganic phosphate administration, it was not significantly raised over the basal value until the third day. Phosphatemia remained normal and constant with FDP, but it rose significantly on the third day of treatment with inorganic phosphate. FDP appears to consistently and rapidly increase DPG levels after transfusion with blood stored in ACD, and to be particularly safe.

21 CFR 73.2110 - Bismuth citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the scalp...

21 CFR 73.2110 - Bismuth citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the scalp...

21 CFR 73.2110 - Bismuth citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the scalp...

21 CFR 73.2110 - Bismuth citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the scalp...

21 CFR 73.2110 - Bismuth citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the scalp...

Effect of Tenapanor on Serum Phosphate in Patients Receiving Hemodialysis

PubMed Central

Rosenbaum, David P.; Leonsson-Zachrisson, Maria; Åstrand, Magnus; Johansson, Susanne; Knutsson, Mikael; Langkilde, Anna Maria; Chertow, Glenn M.

2017-01-01

Hyperphosphatemia is common among patients with CKD stage 5D and is associated with morbidity and mortality. Current guidelines recommend lowering serum phosphate concentrations toward normal. Tenapanor is a minimally absorbed small molecule inhibitor of the sodium/hydrogen exchanger isoform 3 that functions in the gut to reduce sodium and phosphate absorption. This randomized, double-blind, placebo-controlled trial assessed the effects of tenapanor on serum phosphate concentration in patients with hyperphosphatemia receiving hemodialysis. After a 1- to 3-week washout of phosphate binders, we randomly assigned 162 eligible patients (serum phosphate =6.0 to <10.0 mg/dl and a 1.5-mg/dl increase from before washout) to one of six tenapanor regimens (3 or 30 mg once daily or 1, 3, 10, or 30 mg twice daily) or placebo for 4 weeks. The primary efficacy end point was change in serum phosphate concentration from baseline (randomization) to end of treatment. In total, 115 patients (71%) completed the study. Mean serum phosphate concentrations at baseline (after washout) were 7.32–7.92 mg/dl for tenapanor groups and 7.87 mg/dl for the placebo group. Tenapanor provided dose-dependent reductions in serum phosphate level from baseline (least squares mean change: tenapanor =0.47–1.98 mg/dl; placebo =0.54 mg/dl; P=0.01). Diarrhea was the most common adverse event (tenapanor =18%–68%; placebo =12%) and frequent at the highest tenapanor doses. In conclusion, tenapanor treatment resulted in statistically significant, dose-dependent reductions in serum phosphate concentrations in patients with hyperphosphatemia receiving hemodialysis. Additional studies are required to clarify the optimal dosing of tenapanor in patients with CKD-related hyperphosphatemia. PMID:28159782

RNA sequencing to study gene expression and single nucleotide polymorphism variation associated with citrate content in cow milk.

PubMed

Cánovas, A; Rincón, G; Islas-Trejo, A; Jimenez-Flores, R; Laubscher, A; Medrano, J F

2013-04-01

The technological properties of milk have significant importance for the dairy industry. Citrate, a normal constituent of milk, forms one of the main buffer systems that regulate the equilibrium between Ca(2+) and H(+) ions. Higher-than-normal citrate content is associated with poor coagulation properties of milk. To identify the genes responsible for the variation of citrate content in milk in dairy cattle, the metabolic steps involved in citrate and fatty acid synthesis pathways in ruminant mammary tissue using RNA sequencing were studied. Genetic markers that could influence milk citrate content in Holstein cows were used in a marker-trait association study to establish the relationship between 74 single nucleotide polymorphisms (SNP) in 20 candidate genes and citrate content in 250 Holstein cows. This analysis revealed 6 SNP in key metabolic pathway genes [isocitrate dehydrogenase 1 (NADP+), soluble (IDH1); pyruvate dehydrogenase (lipoamide) β (PDHB); pyruvate kinase (PKM2); and solute carrier family 25 (mitochondrial carrier; citrate transporter), member 1 (SLC25A1)] significantly associated with increased milk citrate content. The amount of the phenotypic variation explained by the 6 SNP ranged from 10.1 to 13.7%. Also, genotype-combination analysis revealed the highest phenotypic variation was explained combining IDH1_23211, PDHB_5562, and SLC25A1_4446 genotypes. This specific genotype combination explained 21.3% of the phenotypic variation. The largest citrate associated effect was in the 3' untranslated region of the SLC25A1 gene, which is responsible for the transport of citrate across the mitochondrial inner membrane. This study provides an approach using RNA sequencing, metabolic pathway analysis, and association studies to identify genetic variation in functional target genes determining complex trait phenotypes. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Sildenafil citrate (Viagra) impairs fertilization and early embryo development in mice.

PubMed

Glenn, David R J; McClure, Neil; Cosby, S Louise; Stevenson, Michael; Lewis, Sheena E M

2009-03-01

To determine the effects of sildenafil citrate, a cyclic monophosphate-specific type 5 phosphodiesterase inhibitor known to affect sperm function, on fertilization and early embryo cleavage. This acute mammal study included male and female mice assigned randomly, the females sacrificed after mating and their oocytes/embryos evaluated at four time periods after treatment. Academic research environment. Male and female CBAB(6) mice. Female mice were injected intraperitoneally with 5 IU gonadotropin (hCG) to stimulate follicular growth and induce ovulation. They were each caged with a male that had been gavaged with sildenafil citrate (0.06 mg/0.05 mL) and allowed to mate. After 12, 36, 60, and 84 h, females were killed, their oviducts were dissected out, and retrieved embryos were assessed for blastomere number and quality. Fertilization rates and numbers of embryos were evaluated after treatment. Fertilization rates (day 1) were markedly reduced (-33%) in matings where the male had taken sildenafil citrate. Over days 2-4, the numbers of embryos developing in the treated group were significantly fewer than in the control group. There was also a trend for impaired cleavage rates within those embryos, although this did not reach significance. The impairments to fertility caused by sildenafil citrate have important implications for infertility centers and for couples who are using this drug precoitally while attempting to conceive.

Self-nanoemulsifying drug delivery systems of tamoxifen citrate: design and optimization.

PubMed

Elnaggar, Yosra S R; El-Massik, Magda A; Abdallah, Ossama Y

2009-10-01

Tamoxifen citrate is an antiestrogen for peroral breast cancer treatment. The drug delivery encounters problems of poor water solubility and vulnerability to enzymatic degradation in both intestine and liver. In the current study, tamoxifen citrate self-nanoemulsifying drug delivery systems (SNEDDS) were prepared in an attempt to circumvent such obstacles. Preliminary screening was carried out to select proper ingredient combinations. All surfactants screened were recognized for their bioactive aspects. Ternary phase diagrams were then constructed and an optimum system was designated. Three tamoxifen SNEDDS were then compared for optimization. The systems were assessed for robustness to dilution, globule size, cloud point, surface morphology and drug release. An optimum system composed of tamoxifen citrate (1.6%), Maisine 35-1 (16.4%), Caproyl 90 (32.8%), Cremophor RH40 (32.8%) and propylene glycol (16.4%) was selected. The system was robust to different dilution volumes and types. It possessed a mean globule size of 150 nm and a cloud point of 80 degrees C. Transmission electron microscopy demonstrated spherical particle morphology. The drug release from the selected formulation was significantly higher than other SNEDDS and drug suspension, as well. Realizing drug incorporation into an optimized nano-sized SNEDD system that encompasses a bioactive surfactant, our results proposed that the prepared system could be promising to improve oral efficacy of the tamoxifen citrate.

Mechanism of citrate metabolism by an oxaloacetate decarboxylase-deficient mutant of Lactococcus lactis IL1403.

PubMed

Pudlik, Agata M; Lolkema, Juke S

2011-08-01

Citrate metabolism in resting cells of Lactococcus lactis IL1403(pFL3) results in the formation of two end products from the intermediate pyruvate, acetoin and acetate (A. M. Pudlik and J. S. Lolkema, J. Bacteriol. 193:706-714, 2011). Pyruvate is formed from citrate following uptake by the transporter CitP through the subsequent actions of citrate lyase and oxaloacetate decarboxylase. The present study describes the metabolic response of L. lactis when oxaloacetate accumulates in the cytoplasm. The oxaloacetate decarboxylase-deficient mutant ILCitM(pFL3) showed nearly identical rates of citrate consumption, but the end product profile in the presence of glucose shifted from mainly acetoin to only acetate. In addition, in contrast to the parental strain, the mutant strain did not generate proton motive force. Citrate consumption by the mutant strain was coupled to the excretion of oxaloacetate, with a yield of 80 to 85%. Following citrate consumption, oxaloacetate was slowly taken up by the cells and converted to pyruvate by a cryptic decarboxylase and, subsequently, to acetate. The transport of oxaloacetate is catalyzed by CitP. The parental strain IL1403(pFL3) containing CitP consumed oxaloacetate, while the original strain, IL1403, not containing CitP, did not. Moreover, oxaloacetate consumption was enhanced in the presence of L-lactate, indicating exchange between oxaloacetate and L-lactate catalyzed by CitP. Hence, when oxaloacetate inadvertently accumulates in the cytoplasm, the physiological response of L. lactis is to excrete oxaloacetate in exchange with citrate by an electroneutral mechanism catalyzed by CitP. Subsequently, in a second step, oxaloacetate is taken up by CitP and metabolized to pyruvate and acetate.

Tamoxifen citrate loaded ethosomes for transdermal drug delivery system: preparation and characterization.

PubMed

Sarwa, Khomendra Kumar; Suresh, Preeti K; Debnath, Manabendra; Ahmad, Mohammad Zaki

2013-08-01

Long term tamoxifen citrate therapy is imperative to treat several dermatological and hormonal sensitive disorders. Successful oral and parenteral administration of tamoxifen citrate has been challenging since it undergoes enzymatic degradation and has poor aqueous solubility issues. In the present work, tamoxifen citrate loaded ethosomes were prepared and characterized for transdermal applications. The prepared formulations were characterized for morphological features, particle size distribution, calorimetric attributes, zeta potential and drug entrapment. Permeation profile of prepared ethosomes was compared with liposomes and hydroethonalic solution across cellophane membrane and human cadaver skin. Results of the permeation studies indicate that ethosomes were able to deliver >90% drug within 24 hours of application, while liposomes and hydroethanolic solution delivered only 39.04% and 36.55% respectively. Skin deposition and stability studies are also reported.

[Sonographic ovarian vascularization and volume in women with polycystic ovary syndrome treated with clomiphene citrate and metformin].

PubMed

de la Fuente-Valero, Jesús; Zapardiel-Gutiérrez, Ignacio; Orensanz-Fernández, Inmaculada; Alvarez-Alvarez, Pilar; Engels-Calvo, Virginia; Bajo-Arenas, José Manuel

2010-01-01

To measure the vascularization and ovarian volume with three-dimensional sonography in patients diagnosed of polycystic ovary syndrome with stimulated ovulation treatment, and to analyse the differences between the patients treated with clomiphen citrate versus clomiphen citrate and metformin. Therty patients were studied. Twenty ovulation cycles were obtained with clomiphen citrate and 17 with clomiphen citrate plus merformin (added in case of obesity or hyperglucemy/hyperinsulinemia). Ovarian volumes and vascular indexes were studied with 3D-sonography and results were analysed by treatment. There were no statistical differences of ovarian volume by treatment along the cycles, although bigger volume were found in ovulatory cycles compared to non-ovulatory ones (20,36 versus 13,89 ml, p = 0,026). No statistical differences were also found concerning vascular indexes, neither by treatment nor by the obtention of ovulation in the cycle. Ovarian volume and vascular indexes measured with three-dimensional sonography in patients diagnosed of polycystic ovary syndrome do not show differents values in patients treated with clomiphen citrate alone versus clomiphen citrate plus metformin.

Effects of sodium citrate, citric acid and lactic acid on human blood coagulation.

PubMed

Scaravilli, Vittorio; Di Girolamo, Luca; Scotti, Eleonora; Busana, Mattia; Biancolilli, Osvaldo; Leonardi, Patrizia; Carlin, Andrea; Lonati, Caterina; Panigada, Mauro; Pesenti, Antonio; Zanella, Alberto

2018-05-01

Citric acid infusion in extracorporeal blood may allow concurrent regional anticoagulation and enhancement of extracorporeal CO 2 removal. Effects of citric acid on human blood thromboelastography and aggregometry have never been tested before. In this in vitro study, citric acid, sodium citrate and lactic acid were added to venous blood from seven healthy donors, obtaining concentrations of 9 mEq/L, 12 mEq/L and 15 mEq/L. We measured gas analyses, ionized calcium (iCa ++ ) concentration, activated clotting time (ACT), thromboelastography and multiplate aggregometry. Repeated measure analysis of variance was used to compare the acidifying and anticoagulant properties of the three compounds. Sodium citrate did not affect the blood gas analysis. Increasing doses of citric and lactic acid progressively reduced pH and HCO 3 - and increased pCO 2 (p<0.001). Sodium citrate and citric acid similarly reduced iCa ++ , from 0.39 (0.36-0.39) and 0.35 (0.33-0.36) mmol/L, respectively, at 9 mEq/L to 0.20 (0.20-0.21) and 0.21 (0.20-0.23) mmol/L at 15 mEq/L (p<0.001). Lactic acid did not affect iCa ++ (p=0.07). Sodium citrate and citric acid similarly incremented the ACT, from 234 (208-296) and 202 (178-238) sec, respectively, at 9 mEq/L, to >600 sec at 15 mEq/L (p<0.001). Lactic acid did not affect the ACT values (p=0.486). Sodium citrate and citric acid similarly incremented R-time and reduced α-angle and maximum amplitude (MA) (p<0.001), leading to flat-line thromboelastograms at 15 mEq/L. Platelet aggregometry was not altered by any of the three compounds. Citric acid infusions determine acidification and anticoagulation of blood similar to lactic acid and sodium citrate, respectively.

Protective effect of sildenafil citrate on contralateral testis injury after unilateral testicular torsion/detorsion.

PubMed

Yíldíz, Hamit; Durmus, Ali Said; Simşek, Halil; Yaman, Mine

2011-01-01

This study was designed to investigate prevention of contralateral testicular injury with sildenafil citrate after unilateral testicular torsion/detorsion. Thirty-seven adult male rats were divided into four groups: sham operated (group 1, n = 7), torsion/detorsion + saline (group 2, n = 10), torsion/detorsion + 0.7 mg of sildenafil citrate (group 3, n = 10) and torsion/detorsion + 1.4 mg of sildenafil citrate (group 4, n = 10). Unilateral testicular torsion was created by rotating the right testis 720º in a clockwise direction for 2 h in other groups, except for group 1, which was served as sham group. After torsion (2 h) and detorsion (2 h) periods, rats were killed. The level of reduced glutathion (GSH) (p < 0.05) and the activities of catalase (p < 0.01) and glutathione peroxidase (p < 0.05) in the contralateral testis from group 2 were significantly lower and nitric oxide (NO) (p < 0.05) level in the contralateral testis were significantly higher than those of group 1. Administration of low-dose sildenafil citrate (group 3) prevented the increases in malondialdehyde and NO levels and decreases in glutathione peroxidase activities and GSH values induced by testicular torsion. However, administration of high-dose sildenafil citrate (group 4) had no effect on these testicular parameters (p > 0.05). Histopathological changes were detected in groups 2, 3 and 4. These results suggest that biochemically and histologically torsion/detorsion injury occurs in the contralateral testis following 2-h torsion and 2-h detorsion and that administration of low-dose sildenafil citrate before detorsion prevents ischemia/reperfusion cellular damage in testicular tissue.

The structure and binding mode of citrate in the stabilization of gold nanoparticles

NASA Astrophysics Data System (ADS)

Al-Johani, Hind; Abou-Hamad, Edy; Jedidi, Abdesslem; Widdifield, Cory M.; Viger-Gravel, Jasmine; Sangaru, Shiv Shankar; Gajan, David; Anjum, Dalaver H.; Ould-Chikh, Samy; Hedhili, Mohamed Nejib; Gurinov, Andrei; Kelly, Michael J.; El Eter, Mohamad; Cavallo, Luigi; Emsley, Lyndon; Basset, Jean-Marie

2017-09-01

Elucidating the binding mode of carboxylate-containing ligands to gold nanoparticles (AuNPs) is crucial to understand their stabilizing role. A detailed picture of the three-dimensional structure and coordination modes of citrate, acetate, succinate and glutarate to AuNPs is obtained by 13C and 23Na solid-state NMR in combination with computational modelling and electron microscopy. The binding between the carboxylates and the AuNP surface is found to occur in three different modes. These three modes are simultaneously present at low citrate to gold ratios, while a monocarboxylate monodentate (1κO1) mode is favoured at high citrate:gold ratios. The surface AuNP atoms are found to be predominantly in the zero oxidation state after citrate coordination, although trace amounts of Auδ+ are observed. 23Na NMR experiments show that Na+ ions are present near the gold surface, indicating that carboxylate binding occurs as a 2e- L-type interaction for each oxygen atom involved. This approach has broad potential to probe the binding of a variety of ligands to metal nanoparticles.

Struvite crystal growth inhibition by trisodium citrate and the formation of chemical complexes in growth solution

NASA Astrophysics Data System (ADS)

Prywer, Jolanta; Mielniczek-Brzóska, Ewa; Olszynski, Marcin

2015-05-01

Effect of trisodium citrate on the crystallization of struvite was studied. To evaluate such an effect an experiment of struvite growth from artificial urine was performed. The investigations are related to infectious urinary stones formation. The crystallization process was induced by the addition of aqueous ammonia solution to mimic the bacterial activity. The spectrophotometric results demonstrate that trisodium citrate increases induction time with respect to struvite formation and decreases the growth efficiency of struvite. The inhibitory effect of trisodium citrate on the nucleation and growth of struvite is explained in base of chemical speciation analysis. Such an analysis demonstrates that the inhibitory effect is related with the fact that trisodium citrate binds NH4 + and Mg2+ ions in the range of pH from 7 to 9.5 characteristic for struvite precipitation. The most important is the MgCit- complex whose concentration strongly depends on an increase in pH rather than on an increase in citrate concentrations.

Nucleotide sequence of the gene determining plasmid-mediated citrate utilization.

PubMed Central

Ishiguro, N; Sato, G

1985-01-01

The citrate utilization determinant from transposon Tn3411 has been cloned and sequenced, and its polypeptide products have been characterized in minicell experiments. The nucleotide sequence was determined for a 2,047-base-pair BglII restriction endonuclease fragment that includes the citrate determinant. This region contains an open reading frame that would encode a 431-amino-acid very hydrophobic polypeptide and which is preceded by a reasonable ribosomal binding site. However, the single polypeptide found in minicell experiments had an apparent molecular weight of 35,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Images PMID:2999087

Thermosensitive bioadhesive gels for the vaginal delivery of sildenafil citrate: in vitro characterization and clinical evaluation in women using clomiphene citrate for induction of ovulation.

PubMed

Soliman, Ghareb M; Fetih, Gihan; Abbas, Ahmed M

2017-03-01

The objective of this study is to develop and characterize in situ thermosensitive gels for the vaginal administration of sildenafil as a potential treatment of endometrial thinning occurring as a result of using clomiphene citrate for ovulation induction in women with type II eugonadotrophic anovulation. While sildenafil has shown promising results in the treatment of infertility in women, the lack of vaginal pharmaceutical preparation and the side effects associated with oral sildenafil limit its clinical effectiveness. Sildenafil citrate in situ forming gels were prepared using different grades of Pluronic ® (PF-68 and PF-127). Mucoadhesive polymers as sodium alginate and hydroxyethyl cellulose were added to the gels in different concentrations and the effect on gel properties was studied. The formulations were evaluated in terms of viscosity, gelation temperature (T sol-gel ), mucoadhesion properties, and in vitro drug release characteristics. Selected formulations were evaluated in women with clomiphene citrate failure due to thin endometrium (Clinicaltrial.gov identifier NCT02766725). The T sol-gel decreased with increasing PF-127 concentration and it was modulated by addition of PF-68 to be within the acceptable range of 28-37 °C. Increasing Pluronic® concentration increased gel viscosity and mucoadhesive force but decreased drug release rate. Clinical results showed that the in situ sildenafil vaginal gel significantly increased endometrial thickness and uterine blood flow with no reported side effects. Further, these results were achieved at lower frequency and duration of drug administration. Sildenafil thermosensitive vaginal gels might result in improved potential of pregnancy in anovulatory patients with clomiphene citrate failure due to thin endometrium.

21 CFR 172.755 - Stearyl monoglyceridyl citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Stearyl monoglyceridyl citrate. 172.755 Section 172.755 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR...

Sildenafil citrate for the management of fetal growth restriction and oligohydramnios

PubMed Central

Choudhary, Rana; Desai, Kavita; Parekh, Hetal; Ganla, Kedar

2016-01-01

Fetal growth restriction (FGR) and preeclampsia are the major causes of neonatal morbidity and mortality, which affect up to 8% of all pregnancies. The pathogenesis in FGR is an abnormal trophoblastic invasion leading to compromised uteroplacental circulation. However, in spite of this understanding and identification of high-risk patients, the management options are limited. There are some new studies which have demonstrated the role of sildenafil citrate in improving vasodilatation of small myometrial vessels and therefore improvement in amniotic fluid index, fetal weight, and even uterine and umbilical artery Doppler patterns. We report here the case of a 31-year-old female with infertility and preconceptional thin endometrium responding well to sildenafil citrate, followed by conception. However, she presented with an early-onset FGR at 26 weeks of gestation, and again after treatment with sildenafil citrate, showed improvement in amniotic fluid index and fetal weight, finally resulting in delivery of a full-term healthy baby with uneventful neonatal course. PMID:27563258

The phosphorylation site in double helical amylopectin as investigated by a combined approach using chemical synthesis, crystallography and molecular modeling.

PubMed

Engelsen, Søren Balling; Madsen, Anders Østergaard; Blennow, Andreas; Motawia, Mohammed Saddik; Møller, Birger Lindberg; Larsen, Sine

2003-04-24

The only known in planta substitution of starch is phosphorylation. Whereas the function of starch phosphorylation is poorly understood, phosphorylated starch possesses improved functionality in vitro. Molecular models of native crystalline starch are currently being developed and the starch phosphorylating enzyme has recently been discovered. Accordingly, it is desirable to obtain a more exact description of the molecular structures of phosphorylated starch. We have determined the crystal structure of methyl alpha-D-glucopyranoside 6-O-phosphate as its potassium salt which is thought to be the starch phosphate counterion in vivo. From this structure and previously known glucophosphate structures we describe the possible 6-O-phosphate geometries and through modeling extrapolate the results to the double helical structure of the crystalline part of amylopectin. The geometries of the existing crystal structures of 6-O-phosphate groups were found to belong to two main adiabatic valleys. One of these conformations could be fitted into the double helical amylopectin part without perturbing the double helical amylopectin structure and without creating steric problems for the hexagonal chain-chain packing.

Citrate, malate and alkali content in commonly consumed diet sodas: implications for nephrolithiasis treatment.

PubMed

Eisner, Brian H; Asplin, John R; Goldfarb, David S; Ahmad, Ardalanejaz; Stoller, Marshall L

2010-06-01

Citrate is a known inhibitor of calcium stone formation. Dietary citrate and alkali intake may have an effect on citraturia. Increasing alkali intake also increases urine pH, which can help prevent uric acid stones. We determined citrate, malate and total alkali concentrations in commonly consumed diet sodas to help direct dietary recommendations in patients with hypocitraturic calcium or uric acid nephrolithiasis. Citrate and malate were measured in a lemonade beverage commonly used to treat hypocitraturic calcium nephrolithiasis and in 15 diet sodas. Anions were measured by ion chromatography. The pH of each beverage was measured to allow calculation of the unprotonated anion concentration using the known pK of citric and malic acid. Total alkali equivalents were calculated for each beverage. Statistical analysis was done using Pearson's correlation coefficient. Several sodas contained an amount of citrate equal to or greater than that of alkali and total alkali as a lemonade beverage commonly used to treat hypocitraturic calcium nephrolithiasis (6.30 mEq/l citrate as alkali and 6.30 as total alkali). These sodas were Diet Sunkist Orange, Diet 7Up, Sprite Zero, Diet Canada Dry Ginger Ale, Sierra Mist Free, Diet Orange Crush, Fresca and Diet Mountain Dew. Colas, including Caffeine Free Diet Coke, Coke Zero, Caffeine Free Diet Pepsi and Diet Coke with Lime, had the lowest total alkali (less than 1.0 mEq/l). There was no significant correlation between beverage pH and total alkali content. Several commonly consumed diet sodas contain moderate amounts of citrate as alkali and total alkali. This information is helpful for dietary recommendations in patients with calcium nephrolithiasis, specifically those with hypocitraturia. It may also be useful in patients with low urine pH and uric acid stones. Beverage malate content is also important since malate ingestion increases the total alkali delivered, which in turn augments citraturia and increases urine pH. Copyright

Secreted Citrate Serves as Iron Carrier for the Marine Pathogen Photobacterium damselae subsp damselae

PubMed Central

Balado, Miguel; Puentes, Beatriz; Couceiro, Lucía; Fuentes-Monteverde, Juan C.; Rodríguez, Jaime; Osorio, Carlos R.; Jiménez, Carlos; Lemos, Manuel L.

2017-01-01

Photobacterium damselae subsp damselae (Pdd) is a Vibrionaceae that has a wide pathogenic potential against many marine animals and also against humans. Some strains of this bacterium acquire iron through the siderophore vibrioferrin. However, there are virulent strains that do not produce vibrioferrin, but they still give a strong positive reaction in the CAS test for siderophore production. In an in silico search on the genome sequences of this type of strains we could not find any ORF which could be related to a siderophore system. To identify genes that could encode a siderophore-mediated iron acquisition system we used a mini-Tn10 transposon random mutagenesis approach. From more than 1,400 mutants examined, we could isolate a mutant (BP53) that showed a strong CAS reaction independently of the iron levels of the medium. In this mutant the transposon was inserted into the idh gene, which encodes an isocitrate dehydrogenase that participates in the tricarboxylic acid cycle. The mutant did not show any growth impairment in rich or minimal media, but it accumulated a noticeable amount of citrate (around 7 mM) in the culture medium, irrespective of the iron levels. The parental strain accumulated citrate, but in an iron-regulated fashion, being citrate levels 5–6 times higher under iron restricted conditions. In addition, a null mutant deficient in citrate synthase showed an impairment for growth at high concentrations of iron chelators, and showed almost no reaction in the CAS test. Chemical analysis by liquid chromatography of the iron-restricted culture supernatants resulted in a CAS-positive fraction with biological activity as siderophore. HPLC purification of that fraction yielded a pure compound which was identified as citrate from its MS and NMR spectral data. Although the production of another citrate-based compound with siderophore activity cannot be ruled out, our results suggest that Pdd secretes endogenous citrate and use it for iron scavenging from

Inhibition of calcium oxalate monohydrate growth by citrate and the effect of the background electrolyte

NASA Astrophysics Data System (ADS)

Weaver, Matthew L.; Qiu, S. Roger; Hoyer, John R.; Casey, William H.; Nancollas, George H.; De Yoreo, James J.

2007-08-01

Pathological mineralization is a common phenomenon in broad range of plants and animals. In humans, kidney stone formation is a well-known example that afflicts approximately 10% of the population. Of the various calcium salt phases that comprise human kidney stones, the primary component is calcium oxalate monohydrate (COM). Citrate, a naturally occurring molecule in the urinary system and a common therapeutic agent for treating stone disease, is a known inhibitor of COM. Understanding the physical mechanisms of citrate inhibition requires quantification of the effects of both background electrolytes and citrate on COM step kinetics. Here we report the results of an in situ AFM study of these effects, in which we measure the effect of the electrolytes LiCl, NaCl, KCl, RbCl, and CsCl, and the dependence of step speed on citrate concentration for a range of COM supersaturations. We find that varying the background electrolyte results in significant differences in the measured step speeds and in step morphology, with KCl clearly producing the smallest impact and NaCl the largest. The kinetic coefficient for the former is nearly three times larger than for the latter, while the steps change from smooth to highly serrated when KCl is changed to NaCl. The results on the dependence of step speed on citrate concentration show that citrate produces a dead zone whose width increases with citrate concentration as well as a continual reduction in kinetic coefficient with increasing citrate level. We relate these results to a molecular-scale view of inhibition that invokes a combination of kink blocking and step pinning. Furthermore, we demonstrate that the classic step-pinning model of Cabrera and Vermilyea (C-V model) does an excellent job of predicting the effect of citrate on COM step kinetics provided the model is reformulated to more realistically account for impurity adsorption, include an expression for the Gibbs-Thomson effect that is correct for all supersaturations

The Pregnancy in Polycystic Ovary Syndrome II (PPCOS II) trial: rationale and design of a double-blind randomized trial of clomiphene citrate and letrozole for the treatment of infertility in women with polycystic ovary syndrome.

PubMed

Legro, Richard S; Kunselman, Allen R; Brzyski, Robert G; Casson, Peter R; Diamond, Michael P; Schlaff, William D; Christman, Gregory M; Coutifaris, Christos; Taylor, Hugh S; Eisenberg, Esther; Santoro, Nanette; Zhang, Heping

2012-05-01

Polycystic Ovary Syndrome (PCOS) is a common cause of female infertility and first line treatment is currently oral clomiphene citrate, a selective estrogen receptor modulator, which results in both a high nonresponse rate and multiple pregnancy rate. Aromatase inhibitors such as letrozole may have more favorable ovarian and endometrial effects. The goal of the Pregnancy in Polycystic Ovary Syndrome II (PPCOSII) study is to determine the safety and efficacy of clomiphene citrate (CC) compared to letrozole, in achieving live birth in infertile women with PCOS. The population will consist of 750 infertile women with PCOS. Additionally, the couple will have no other major infertility factor. This will be a multi-center, prospective, double-blind clinical trial of CC vs. letrozole for 5 treatment cycles (or approximately up to 25 weeks). The randomization scheme will be coordinated through the central data coordinating center (DCC) and the randomization is stratified by each participating site. After progestin withdrawal as needed, 750 women will be equally randomized to two different treatment arms: A) CC 50mg every day for 5 days (days 3-7 of cycle), or B) letrozole 2.5mg every day for 5 days (days 3-7 of cycle), for a total of 5 cycles or 25 weeks. The dose will be increased in subsequent cycles in both treatment groups for non-response or poor ovulatory response up to a maximum of 150 mg of CC a day (×5 days) or 7.5mg of letrozole a day (×5 days). The primary analysis will use an intent-to-treat approach to examine differences in the live birth rate in the two treatment arms. Copyright © 2012 Elsevier Inc. All rights reserved.

pH-specific synthesis and spectroscopic, structural, and magnetic studies of a chromium(III)-citrate species. Aqueous solution speciation of the binary chromium(III)-citrate system.

PubMed

Gabriel, C; Raptopoulou, C P; Terzis, A; Tangoulis, V; Mateescu, C; Salifoglou, A

2007-04-16

In an attempt to understand the aqueous interactions of Cr(III) with the low-molecular-mass physiological ligand citric acid, the pH-specific synthesis in the binary Cr(III)-citrate system was explored, leading to the complex (NH4)4[Cr(C6H4O7)(C6H5O7)].3H2O (1). 1 crystallizes in the monoclinic space group I2/a, with a = 19.260(10) A, b = 10.006(6) A, c = 23.400(10) A, beta = 100.73(2) degrees , V = 4431(4) A3, and Z = 8. 1 was characterized by elemental analysis and spectroscopic, structural, thermal, and magnetic susceptibility studies. Detailed aqueous speciation studies in the Cr(III)-citrate system suggest the presence of a number of species, among which is the mononuclear [Cr(C6H4O7)(C6H5O7)]4- complex, optimally present around pH approximately 5.5. The structure of 1 reveals a mononuclear octahedral complex of Cr(III) with two citrate ligands bound to it. The two citrate ligands have different deprotonation states, thus signifying the importance of the mixed deprotonation state in the coordination sphere of the Cr(III) species in aqueous speciation. The latter reveals the distribution of numerous species, including 1, for which the collective structural, spectroscopic, and magnetic data point out its physicochemical profile in the solid state and in solution. The importance of the synthetic efforts linked to 1 and the potential ramifications of Cr(III) reactivity toward both low- and high-molecular-mass biotargets are discussed in light of (a) the quest for well-characterized soluble Cr(III) species that could be detected and identified in biologically relevant fluids, (b) ongoing efforts to delineate the aqueous speciation of the Cr(III)-citrate system and its link to biotoxic Cr(III) manifestations, and (c) the synthetic utility of convenient Cr(III) precursors in the synthesis of advanced materials.

Separation of Ni and Co by D2EHPA in the Presence of Citrate Ion

NASA Astrophysics Data System (ADS)

Nadimi, Hamed; Haghshenas Fatmehsari, Davoud; Firoozi, Sadegh

2017-10-01

Recycling processes for the recovery of metallic content from the electronic wastes are environmentally friendly and economical. This paper reports a method for the recovery and separation of Ni and Co from the sulfate solution by the use of D2EHPA. In this regard, the influence of citrate ion, as a carboxylate ligand, was examined in the separation conditions of Ni and Co via D2EHPA (a poor selective extractant for Ni and Co separation). It was found that the Δ {pH}_{0.5}^{Ni-Co} (the difference between pH values corresponding to 50 pct extraction of metallic ion) increases to 1.5 at the citrate concentration of 0.05 M; this Δ {pH}_{0.5}^{Ni-Co} value is much higher than that obtained in the absence of citrate ion (0.1). Fourier Transform Infrared Spectroscopy (FT-IR) indicated that the citrate ion is co-absorbed during the metallic ions absorption by D2EHPA meaning that the metal-organic complexes contain Co/Ni and citrate ion. Also, the stoichiometric coefficients of the Ni and Co extraction reaction were proposed by applying the slope analysis method.

21 CFR 522.300 - Carfentanil citrate injection.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522... effect, use 7 milligrams of diprenorphine for each milligram of carefentanil citrate, given intravenously... animals intended for food. Do not use 30 days before or during hunting season. Do not use in animals that...

21 CFR 573.560 - Iron ammonium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Iron ammonium citrate. 573.560 Section 573.560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food...

21 CFR 573.560 - Iron ammonium citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Iron ammonium citrate. 573.560 Section 573.560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food...

21 CFR 573.560 - Iron ammonium citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Iron ammonium citrate. 573.560 Section 573.560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food...

21 CFR 573.560 - Iron ammonium citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Iron ammonium citrate. 573.560 Section 573.560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food...

21 CFR 573.560 - Iron ammonium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Iron ammonium citrate. 573.560 Section 573.560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food...

Functional Analysis of the Citrate Activator CitO from Enterococcus faecalis Implicates a Divalent Metal in Ligand Binding

PubMed Central

Blancato, Víctor S.; Pagliai, Fernando A.; Magni, Christian; Gonzalez, Claudio F.; Lorca, Graciela L.

2016-01-01

The regulator of citrate metabolism, CitO, from Enterococcus faecalis belongs to the FCD family within the GntR superfamily. In the presence of citrate, CitO binds to cis-acting sequences located upstream of the cit promoters inducing the expression of genes involved in citrate utilization. The quantification of the molecular binding affinities, performed by isothermal titration calorimetry (ITC), indicated that CitO has a high affinity for citrate (KD = 1.2 ± 0.2 μM), while it did not recognize other metabolic intermediates. Based on a structural model of CitO where a putative small molecule and a metal binding site were identified, it was hypothesized that the metal ion is required for citrate binding. In agreement with this model, citrate binding to CitO sharply decreased when the protein was incubated with EDTA. This effect was reverted by the addition of Ni2+, and Zn2+ to a lesser extent. Structure-based site-directed mutagenesis was conducted and it was found that changes to alanine in residues Arg97 and His191 resulted in decreased binding affinities for citrate, as determined by EMSA and ITC. Further assays using lacZ fusions confirmed that these residues in CitO are involved in sensing citrate in vivo. These results indicate that the molecular modifications induced by a ligand and a metal binding in the C-terminal domain of CitO are required for optimal DNA binding activity, and consequently, transcriptional activation. PMID:26903980

SECONDARY HYPERPARATHYROIDISM AFTER BARIATRIC SURGERY: TREATMENT IS WITH CALCIUM CARBONATE OR CALCIUM CITRATE?

PubMed Central

BARETTA, Giorgio Alfredo Pedroso; CAMBI, Maria Paula Carlini; RODRIGUES, Arieli Luz; MENDES, Silvana Aparecida

2015-01-01

Background : Bariatric surgery, especially Roux-en-Y gastric bypass, can cause serious nutritional complications arising from poor absorption of essential nutrients. Secondary hyperparathyroidism is one such complications that leads to increased parathyroid hormone levels due to a decrease in calcium and vitamin D, which may compromise bone health. Aim : To compare calcium carbonate and calcium citrate in the treatment of secondary hyperparathyroidism. Method : Patients were selected on the basis of their abnormal biochemical test and treatment was randomly done with citrate or calcium carbonate. Results : After 60 days of supplementation, biochemical tests were repeated, showing improvement in both groups. Conclusion : Supplementation with calcium (citrate or carbonate) and vitamin D is recommended after surgery for prevention of secondary hyperparathyroidism. PMID:26537273

Fabrication and cytocompatibility of spherical magnesium ammonium phosphate granules.

PubMed

Christel, Theresa; Geffers, Martha; Klammert, Uwe; Nies, Berthold; Höß, Andreas; Groll, Jürgen; Kübler, Alexander C; Gbureck, Uwe

2014-09-01

Magnesium phosphate compounds, as for example struvite (MgNH4PO4·6H2O), have comparable characteristics to calcium phosphate bone substitutes, but degrade faster under physiological conditions. In the present work, we used a struvite forming calcium doped magnesium phosphate cement with the formulation Ca0.75Mg2.25(PO4)2 and an ammonium phosphate containing aqueous solution to produce round-shaped granules. For the fabrication of spherical granules, the cement paste was dispersed in a lipophilic liquid and stabilized by surfactants. The granules were characterized with respect to morphology, size distribution, phase composition, compressive strength, biocompatibility and solubility. In general, it was seen that small granules can hardly be produced by means of emulsification, when the raw material is a hydraulic paste, because long setting times promote coalescence of initially small unhardened cement droplets. Here, this problem was solved by using an aqueous solution containing both the secondary (NH4)2HPO4 and primary ammonium phosphates NH4H2PO4 to accelerate the setting reaction. This resulted in granules with 97 wt.% having a size in the range between 200 and 1,000 μm. The novel solution composition doubled the compressive strength of the cement to 37 ± 5 MPa without affecting either the conversion to struvite or the cytocompatibility using human fetal osteoblasts. Copyright © 2014 Elsevier B.V. All rights reserved.

Soybean NADP-Malic Enzyme Functions in Malate and Citrate Metabolism and Contributes to Their Efflux under Al Stress.

PubMed

Zhou, Ying; Yang, Zhenming; Xu, Yuezi; Sun, Haoran; Sun, Zhitao; Lin, Bao; Sun, Wenjing; You, Jiangfeng

2017-01-01

Malate accumulation has been suggested to balance Al-induced citrate synthesis and efflux in soybean roots. To test this hypothesis, characteristics of Al-induced accumulation and efflux of citrate and malate were compared between two soybean genotypes combining a functional analysis of GmME1 putatively encode a cytosolic NADP-malic enzyme. Similar amounts of citrate were released, and root elongation was equally inhibited before 8 h of Al treatment of Jiyu 70 and Jiyu 62 cultivars. Jiyu 70 began to secrete more citrate and exhibited higher Al resistance than did Jiyu 62 at 12 h. A sustained increase in internal malate and citrate concentrations was observed in Jiyu 70 at 24 h of Al treatment. However, Jiyu 62 decreased its malate concentration at 12 h and its citrate concentration at 24 h of Al treatment. GmME1 localized to the cytoplast and clustered closely with cytosolic malic enzymes AtME2 and SgME1 and was constitutively expressed in the roots. Al treatment induced higher NADP-malic enzyme activities and GmME1 expression levels in Jiyu 70 than in Jiyu 62 within 24 h. Compared with wild-type hairy roots, over-expressing GmME1 in hairy roots ( GmME1 -OE) produced higher expression levels of GmME1 but did not change the expression patterns of either of the putative citrate transporter genes GmAACT1 and GmFRDL or the malate transporter gene GmALMT1 , with or without Al treatment. GmME1 -OE showed a higher internal concentration and external efflux of both citrate and malate at 4 h of Al stress. Lighter hematoxylin staining and lower Al contents in root apices of GmME1 -OE hairy roots indicated greater Al resistance. Comprehensive experimental results suggest that sustaining Al-induced citrate efflux depends on the malate pool in soybean root apices. GmME1 encodes a cytosolic malic enzyme that contributes to increased internal malate and citrate concentrations and their external efflux to confer higher Al resistance.

Comparative Effectiveness of Phosphate Binders in Patients with Chronic Kidney Disease: A Systematic Review and Network Meta-Analysis.

PubMed

Sekercioglu, Nigar; Thabane, Lehana; Díaz Martínez, Juan Pablo; Nesrallah, Gihad; Longo, Christopher J; Busse, Jason W; Akhtar-Danesh, Noori; Agarwal, Arnav; Al-Khalifah, Reem; Iorio, Alfonso; Guyatt, Gordon H

2016-01-01

Chronic kidney disease-mineral and bone disorder (CKD-MBD) has been linked to poor health outcomes, including diminished quality and length of life. This condition is characterized by high phosphate levels and requires phosphate-lowering agents-phosphate binders. The objective of this systematic review is to compare the effects of available phosphate binders on patient-important outcomes in patients with CKD-MBD. Data sources included MEDLINE and EMBASE Trials from 1996 to February 2016. We also searched the Cochrane Register of Controlled Trials up to April 2016. Teams of two reviewers, independently and in duplicate, screened titles and abstracts and potentially eligible full text reports to determine eligibility, and subsequently abstracted data and assessed risk of bias in eligible randomized controlled trials (RCTs). Eligible trials enrolled patients with CKD-MBD, randomized them to receive calcium (delivered as calcium acetate, calcium citrate or calcium carbonate), non-calcium-based phosphate binders (NCBPB) (sevelamer hydrochloride, sevelamer carbonate, lanthanum carbonate, sucroferric oxyhydroxide and ferric citrate), phosphorus restricted diet, placebo or no treatment, and reported effects on all-cause mortality, cardiovascular mortality or hospitalization at ≥4 weeks follow-up. We performed network meta-analyses (NMA) for all cause-mortality for individual agents (seven-node analysis) and conventional meta-analysis of calcium vs. NCBPBs for all-cause mortality, cardiovascular mortality and hospitalization. In the NMAs, we calculated the effect estimates for direct, indirect and network meta-analysis estimates; for both NMA and conventional meta-analysis, we pooled treatment effects as risk ratios (RR) and calculated 95% confidence intervals (CIs) using random effect models. We used the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach to rate the quality of evidence for each paired comparison. Our search yielded 1190

Calcium phosphate coatings on magnesium alloys for biomedical applications: a review.

PubMed

Shadanbaz, Shaylin; Dias, George J

2012-01-01

Magnesium has been suggested as a revolutionary biodegradable metal for use as an orthopaedic material. As a biocompatible and degradable metal, it has several advantages over the permanent metallic materials currently in use, including eliminating the effects of stress shielding, improving biocompatibility concerns in vivo and improving degradation properties, removing the requirement of a second surgery for implant removal. The rapid degradation of magnesium, however, is a double-edged sword as it is necessary to control the corrosion rates of the materials to match the rates of bone healing. In response, calcium phosphate coatings have been suggested as a means to control these corrosion rates. The potential calcium phosphate phases and their coating techniques on substrates are numerous and can provide several different properties for different applications. The reactivity and low melting point of magnesium, however, require specific parameters for calcium phosphate coatings to be successful. Within this review, an overview of the different calcium phosphate phases, their properties and their behaviour in vitro and in vivo has been provided, followed by the current coating techniques used for calcium phosphates that may be or may have been adapted for magnesium substrates. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Prophylactic sildenafil citrate improves select aspects of sexual function in men treated with radiotherapy for prostate cancer.

PubMed

Zelefsky, Michael J; Shasha, Daniel; Branco, Rebekah Dunn; Kollmeier, Marisa; Baser, Raymond E; Pei, Xin; Ennis, Ronald; Stock, Richard; Bar-Chama, Natan; Mulhall, John P

2014-09-01

We studied adjuvant daily sildenafil citrate during and after radiotherapy for prostate cancer for erectile function preservation. We performed a randomized, prospective trial of 279 patients with localized prostate cancer treated with radiotherapy who received sildenafil citrate (50 mg daily) or placebo (2:1 randomization). Medication/placebo was initiated 3 days before treatment and continued daily for 6 months. Before therapy and 3, 6, 9, 12, 18 and 24 months after radiotherapy patients completed the IIEF questionnaire, including the erectile function domain, the I-PSS questionnaire and the RAND SF-36®. All IIEF domains were scored. At 12 months erectile function scores were better for sildenafil citrate than placebo (p = 0.018), 73% of patients on sildenafil citrate vs 50% on placebo had mild/no erectile dysfunction (p = 0.024) and the sildenafil citrate arm had superior overall satisfaction (p = 0.027) and IIEF total scores (p = 0.043). At 24 months erectile function and IIEF scores were no longer significantly better for sildenafil citrate (p = 0.172 and 0.09, respectively) and yet overall satisfaction scores were higher (p = 0.033). Sexual desire scores in patients who received sildenafil citrate were higher at 24 months although they had completed drug therapy 18 months previously (p = 0.049). At 24 months 81.6% of patients on sildenafil citrate and 56.0% of those on placebo achieved functional erection with or without erectile dysfunction medication (p = 0.045). Daily sildenafil citrate during and after radiotherapy for prostate cancer was associated with improved overall sexual function compared with placebo for various sexual function domains. To our knowledge this is the largest randomized, prospective, controlled trial to show the usefulness of a phosphodiesterase-5 inhibitor as a rehabilitation strategy in patients with prostate cancer who received radiation therapy. Copyright © 2014 American Urological Association Education and Research, Inc

Determination of Zn-citrate in human milk by CIM monolithic chromatography with atomic and mass spectrometry detection.

PubMed

Milačič, Radmila; Ajlec, Dejan; Zuliani, Tea; Žigon, Dušan; Ščančar, Janez

2012-11-15

In human milk zinc (Zn) is bound to proteins and low molecular mass (LMM) ligands. Numerous investigations demonstrated that Zn bioavailability in human milk is for infant much higher than in cow's milk. It was presumed that in the LMM human milk fraction highly bioavailable Zn-citrate prevails. However, literature data are controversial regarding the amount of Zn-citrate in human milk since analytical procedures reported were not quantitative. So, complex investigation was carried out to develop analytical method for quantitative determination of this biologically important molecule. Studies were performed within the pH range 5-7 by the use of synthetic solutions of Zn-citrate prepared in HEPES, MOPS and MES buffers. Zn-citrate was separated on weak anion-exchange convective interaction media (CIM) diethylaminoethyl (DEAE) monolithic chromatographic column using NH(4)NO(3) as an eluent. Separated Zn species were determined by flame atomic absorption spectrometry (FAAS) or inductively coupled plasma mass spectrometry (ICP-MS). Quantitative separation of Zn-citrate complexes ([Zn(Cit)](-) and [Zn(Cit)(2)](4-); column recoveries 94-102%) and good repeatability and reproducibility of results with relative standard deviation (RSD±3.0%) were obtained. In fractions under the chromatographic peaks Zn-binding ligand was identified by electrospray ionization tandem mass spectrometry (ESI-MS-MS). Limits of detection (LOD) for determination of Zn-citrate species by CIM DEAE-FAAS and CIM DEAE-ICP-MS were 0.01 μg Zn mL(-1) and 0.0005 μg Zn mL(-1), respectively. Both techniques were sensitive enough for quantification of Zn-citrate in human milk. Results demonstrated that about 23% of total Zn was present in the LMM milk fraction and that LMM-Zn corresponded to Zn-citrate. The developed speciation method represents a reliable analytical tool for investigation of the percentage and the amount of Zn-citrate in human milk. Copyright © 2012 Elsevier B.V. All rights reserved.

Concave Urinary Crystallines: Direct Evidence of Calcium Oxalate Crystals Dissolution by Citrate In Vivo

PubMed Central

Shang, Yun-Feng; Xu, Meng; Zhang, Guang-Na; Ouyang, Jian-Ming

2013-01-01

The changes in urinary crystal properties in patients with calcium oxalate (CaOx) calculi after oral administration of potassium citrate (K3cit) were investigated via atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray powder diffractometry (XRD), and zeta potential analyzer. The AFM and SEM results showed that the surface of urinary crystals became concave, the edges and corners of crystals became blunt, the average size of urinary crystallines decreased significantly, and aggregation of urinary crystals was reduced. These changes were attributed to the significant increase in concentration of excreted citrate to 492 ± 118 mg/L after K3cit intake from 289 ± 83 mg/L before K3cit intake. After the amount of urinary citrate was increased, it complexed with Ca2+ ions on urinary crystals, which dissolved these crystals. Thus, the appearance of concave urinary crystals was a direct evidence of CaOx dissolution by citrate in vivo. The XRD results showed that the quantities and species of urinary crystals decreased after K3cit intake. The mechanism of inhibition of formation of CaOx stones by K3cit was possibly due to the complexation of Ca2+ with citrate, increase in urine pH, concentration of urinary inhibitor glycosaminoglycans (GAGs), and the absolute value of zeta potential after K3cit intake. PMID:24363634

Ovulation induction with clomiphene citrate and metformin in women with polycystic ovary syndrome.

PubMed

Leanza, V; Coco, L; Grasso, F; Leanza, G; Zarbo, G; Palumbo, M

2014-06-01

Polycystic ovary syndrome (PCOS) is one of the most common causes of ovulatory infertility. It is an endocrine disorders characterized by a high level of male hormones (androgens) and frequent anovulatory cycles associated with multiple ovarian microcysts. The aim of this paper was to evaluate effects of a Clomiphene citrate alone versus a combined treatment (Metformin and Clomiphene citrate). A total of 60 women with PCOS and infertility were evaluated. Inclusions criteria were: age 26-34 years, nulliparity, above 3 years of sterility, multiple ovarian microcysts, BMI>27.5, oligomenorrhea/amenorrhea, hyperandrogenism and normal male fertility. Four patients were excluded (renal damage 2, tubal occlusion 1 and Pelvic Inflammatory Disease 1). The remaining 56 were divided into 2 groups: group A were inducted with Clomiphene Citrate alone, while group B were inducted with Clomiphene citrate and Metformin. In group A we obtained ovulation in 20 women (71.4%), 8 pregnancies (28.5%) and one (3.5%) spontaneous abortion. In group B we obtained ovulation in 24 women (85.7%), 15 pregnancies (53.5%) and no spontaneous abortions. Combined treatment was found to be more effective (53.5) in improving pregnancy rate compared to monotherapy (28.5%).

Extemporaneous sildenafil citrate oral suspensions for the treatment of pulmonary hypertension in children.

PubMed

Nahata, Milap C; Morosco, Richard S; Brady, Michael T

2006-02-01

The stability of sildenafil citrate 2.5 mg/mL in two extemporaneously prepared oral suspensions stored at 4 and 25 degrees C was studied. Thirty 25-mg tablets of sildenafil citrate were ground to powder, and the powder was combined with a 1:1 mixture of Ora-Sweet and Ora-Plus or a 1:1 mixture of methylcellulose 1% and Simple Syrup, NF, to produce two 2.5-mg/mL suspensions. Five plastic bottles of each suspension were stored in amber plastic prescription bottles at 4 or 25 degrees C. Samples were collected on days 0, 7, 14, 28, 42, 56, 70, and 91 for analysis of sildenafil content by high-performance liquid chromatography; pH was also measured. Samples were visually observed against black and white backgrounds. The mean concentration of sildenafil citrate exceeded 98% of the initial concentration in all samples at both temperatures throughout the 91-day study period. No changes in pH, odor, or physical appearance were observed. Sildenafil citrate 2.5 mg/mL in two extemporaneously compounded oral suspensions was stable for 91 days in plastic prescription bottles at 4 and 25 degrees C.

Melatonin protects against clomiphene citrate-induced generation of hydrogen peroxide and morphological apoptotic changes in rat eggs.

PubMed

Tripathi, Anima; PremKumar, Karuppanan V; Pandey, Ashutosh N; Khatun, Sabana; Mishra, Surabhi Kirti; Shrivastav, Tulsidas G; Chaube, Shail K

2011-09-30

The present study was aimed to determine whether clomiphene citrate-induces generation of hydrogen peroxide in ovary, if so, whether melatonin could scavenge hydrogen peroxide and protect against clomiphene citrate-induced morphological apoptotic changes in rat eggs. For this purpose, forty five sexually immature female rats were given single intramuscular injection of 10 IU pregnant mare's serum gonadotropin for 48 h followed by single injections of 10 IU human chorionic gonadotropin and clomiphene citrate (10 mg/kg bw) with or without melatonin (20 mg/kg bw) for 16 h. The histology of ovary, ovulation rate, hydrogen peroxide concentration and catalase activity in ovary and morphological changes in ovulated eggs were analyzed. Co-administration of clomiphene citrate along with human chorionic gonadotropin significantly increased hydrogen peroxide concentration and inhibited catalase activity in ovary, inhibited ovulation rate and induced egg apoptosis. Supplementation of melatonin reduced hydrogen peroxide concentration and increased catalase activity in the ovary, delayed meiotic cell cycle progression in follicular oocytes as well as in ovulated eggs since extrusion of first polar body was still in progress even after ovulation and protected against clomiphene citrate-induced egg apoptosis. These results clearly suggest that the melatonin reduces oxidative stress by scavenging hydrogen peroxide produced in the ovary after clomiphene citrate treatment, slows down meiotic cell cycle progression in eggs and protects against clomiphene citrate-induced apoptosis in rat eggs. Copyright © 2011 Elsevier B.V. All rights reserved.

Effect of temperature on copper, iron and lead leaching from e-waste using citrate solutions.

PubMed

Torres, Robinson; Segura-Bailón, Brenda; Lapidus, Gretchen T

2018-01-01

E-waste is a potential source of large quantities of metals. The ability of citrate solutions to recover base metals from these materials has been demonstrated. In the present study, the effect of the temperature on base metal leaching capacity by the citrate solutions is determined. The material employed consisted of a mechanically prepared, gravity concentrated e-waste, with a metallic content greater than 90%. The leaching conditions were selected based on previous research performed by the authors (0.5 M sodium citrate, pH 4.5 and 20 g per liter e-waste concentrate). Leaching tests were performed at temperatures between 0° and 70 °C. The initial leaching rates for the three metals increased with temperature. However, these tapered off with time for temperatures above 30 °C, which can be associated to citrate destruction. Copyright © 2017 Elsevier Ltd. All rights reserved.

40 CFR 721.7285 - Amines, N-cocoalkyltrimethylenedi-, citrates.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amines, N-cocoalkyltrimethylenedi... Specific Chemical Substances § 721.7285 Amines, N-cocoalkyltrimethylenedi-, citrates. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as amines, N...

40 CFR 721.7286 - Amines, N-tallowalkyltripropylenetetra-, citrates.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amines, N-tallowalkyltripropylenetetra... Specific Chemical Substances § 721.7286 Amines, N-tallowalkyltripropylenetetra-, citrates. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as amines, N...

40 CFR 721.7285 - Amines, N-cocoalkyltrimethylenedi-, citrates.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amines, N-cocoalkyltrimethylenedi... Specific Chemical Substances § 721.7285 Amines, N-cocoalkyltrimethylenedi-, citrates. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as amines, N...

40 CFR 721.7286 - Amines, N-tallowalkyltripropylenetetra-, citrates.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amines, N-tallowalkyltripropylenetetra... Specific Chemical Substances § 721.7286 Amines, N-tallowalkyltripropylenetetra-, citrates. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as amines, N...

Gastrografin as an alternative booster to sodium phosphate in colon capsule endoscopy: safety and efficacy pilot study*

PubMed Central

Togashi, Kazutomo; Fujita, Tomoki; Utano, Kenichi; Waga, Eriko; Katsuki, Shinichi; Isohata, Noriyuki; Endo, Shungo; Lefor, Alan K.

2015-01-01

Background and study aims: Sodium phosphate is a key component of bowel preparation regimen for colon capsule endoscopy (CCE), but may cause serious complications. The aim of this study is to evaluate the use of Gastrografin, substituted for sodium phosphate, in CCE bowel preparation. Patients and methods: In total, 29 patients (median age 64 years; 23 females) underwent CCE, covered by the national health insurance system of Japan. All had a history of laparotomy and/or previously incomplete colonoscopy. On the day before examination, patients ingested 1 L of polyethylene glycol + ascorbic acid with 0.5 L of water in the evening, and again the same laxative on the morning of examination. After capsule ingestion, 50 mL of Gastrografin diluted with 0.9 L of magnesium citrate was administered, and then repeated after 1 hour. Results: The capsule excretion rate was 97 % (28/29). The median colon transit time was 2 hours 45 minutes and rapid transit (< 40 minutes) through the colon occurred in one patient (3.4 %). Bowel cleansing level was adequate in 90 % of patients. The polyp (≥ 6 mm) detection rate was 52 %. Diluted Gastrografin was well tolerated by patients. No adverse events occurred. Conclusion: Gastrografin can be an alternative to sodium phosphate in CCE bowel preparation regimen. PMID:26716132

Comparative effectiveness of 30 % trisodium citrate and heparin lock solution in preventing infection and dysfunction of hemodialysis catheters: a randomized controlled trial (CITRIM trial).

PubMed

Correa Barcellos, Franklin; Pereira Nunes, Bruno; Jorge Valle, Luciana; Lopes, Thiago; Orlando, Bianca; Scherer, Cintia; Nunes, Marcia; Araújo Duarte, Gabriela; Böhlke, Maristela

2017-04-01

Central venous catheters (CVC) are the only option when hemodialysis is needed for patients without definitive vascular access. However, CVC is associated with complications, such as infection, thrombosis, and dysfunction, leading to higher mortality and expenditures. The aim of this study was to compare the effectiveness of 30 % trisodium citrate (TSC30 %) with heparin as CVC lock solutions in preventing catheter-related bloodstream infections (CRBSI) and dysfunction in hemodialysis patients. Randomized, double-blind controlled trial comparing the event-free survival of non-tunneled CVC locked with heparin or TSC30 % in adult hemodialysis patients. The study included 464 catheters, 233 in heparin group, and 231 in TSC30 % group. The CRBSI-free survival of TSC30 % group was significantly shorter than that of heparin group. When stratified by insertion site, heparin was better than TSC30 % only in subclavian CVC. The dysfunction-free survival was not different between groups in the main analysis, but there is also a shorter survival among subclavian CVC locked with TSC30 % in stratified analysis. There was no difference on CRBSI-free or dysfunction-free survival between jugular vein CVC locked with heparin or 30 % citrate. However, subclavian CVC locked with 30 % citrate presented shorter event-free survival. This difference may be related to anatomical and positional effects, CVC design, and hydraulic aspects of the lock solution. CLINICALTRIALS. NCT02563041.

Flexible biodegradable citrate-based polymeric step-index optical fiber.

PubMed

Shan, Dingying; Zhang, Chenji; Kalaba, Surge; Mehta, Nikhil; Kim, Gloria B; Liu, Zhiwen; Yang, Jian

2017-10-01

Implanting fiber optical waveguides into tissue or organs for light delivery and collection is among the most effective ways to overcome the issue of tissue turbidity, a long-standing obstacle for biomedical optical technologies. Here, we report a citrate-based material platform with engineerable opto-mechano-biological properties and demonstrate a new type of biodegradable, biocompatible, and low-loss step-index optical fiber for organ-scale light delivery and collection. By leveraging the rich designability and processibility of citrate-based biodegradable polymers, two exemplary biodegradable elastomers with a fine refractive index difference and yet matched mechanical properties and biodegradation profiles were developed. Furthermore, we developed a two-step fabrication method to fabricate flexible and low-loss (0.4 db/cm) optical fibers, and performed systematic characterizations to study optical, spectroscopic, mechanical, and biodegradable properties. In addition, we demonstrated the proof of concept of image transmission through the citrate-based polymeric optical fibers and conducted in vivo deep tissue light delivery and fluorescence sensing in a Sprague-Dawley (SD) rat, laying the groundwork for realizing future implantable devices for long-term implantation where deep-tissue light delivery, sensing and imaging are desired, such as cell, tissue, and scaffold imaging in regenerative medicine and in vivo optogenetic stimulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cloning of the citrate permease gene of Lactococcus lactis subsp. lactis biovar diacetylactis and expression in Escherichia coli.

PubMed Central

Sesma, F; Gardiol, D; de Ruiz Holgado, A P; de Mendoza, D

1990-01-01

The citrate plasmid (Cit+ plasmid) from Lactococcus lactis subsp. lactis biovar diacetylactis was cloned into the EcoRI site of plasmid pUC18. This recombinant plasmid enabled Escherichia coli K-12 to transport and utilize citrate as a source of energy, indicating expression of the citrate permease from L. lactis biovar diacetylactis. The citrate permease was under the control of the lac promoter of pUC18. Genetic expression of the Cit+ plasmid in maxicells revealed that the plasmid encoded two polypeptides of 47 and 32 kilodaltons, determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Images PMID:2117878

Use of Potassium Citrate to Reduce the Risk of Renal Stone Formation During Spaceflight

NASA Technical Reports Server (NTRS)

Whitson, P. A.; Pietrzyk, R. A.; Sams, C. F.; Jones, J. A.; Nelman-Gonzalez, M.; Hudson, E. K.

2008-01-01

Introduction: NASA s Vision for Space Exploration centers on exploration class missions including the goals of returning to the moon and landing on Mars. One of NASA s objectives is to focus research on astronaut health and the development of countermeasures that will protect crewmembers during long duration voyages. Exposure to microgravity affects human physiology and results in changes in the urinary chemical composition favoring urinary supersaturation and an increased risk of stone formation. Nephrolithiasis is a multifactorial disease and development of a renal stone is significantly influenced by both dietary and environmental factors. Previous results from long duration Mir and short duration Shuttle missions have shown decreased urine volume, pH, and citrate levels and increased calcium. Citrate, an important inhibitor of calcium-containing stones, binds with urinary calcium reducing the amount of calcium available to form stones. Citrate inhibits renal stone recurrence by preventing crystal growth, aggregation, and nucleation and is one of the most common therapeutic agents used to prevent stone formation. Methods: Thirty long duration crewmembers (29 male, 1 female) participated in this study. 24-hour urines were collected and dietary monitoring was performed pre, in, and postflight. Crewmembers in the treatment group received two potassium citrate (KCIT) pills, 10 mEq/pill, ingested daily beginning 3 days before launch, all inflight days and through 14 days postflight. Urinary biochemical and dietary analyses were completed. Results: KCIT treated subjects exhibited decreased urinary calcium excretion and maintained the levels of calcium oxalate supersaturation risk at their preflight levels. The increased urinary pH levels in these subjects reduced the risk of uric acid stones. Discussion: The current study investigated the use of potassium citrate as a countermeasure to minimize the risk of stone formation during ISS missions. Results suggest that

Nitric oxide induces the alternative oxidase pathway in Arabidopsis seedlings deprived of inorganic phosphate.

PubMed

Royo, Beatriz; Moran, Jose F; Ratcliffe, R George; Gupta, Kapuganti J

2015-10-01

Phosphate starvation compromises electron flow through the cytochrome pathway of the mitochondrial electron transport chain, and plants commonly respond to phosphate deprivation by increasing flow through the alternative oxidase (AOX). To test whether this response is linked to the increase in nitric oxide (NO) production that also increases under phosphate starvation, Arabidopsis thaliana seedlings were grown for 15 d on media containing either 0 or 1mM inorganic phosphate. The effects of the phosphate supply on growth, the production of NO, respiration, the AOX level and the production of superoxide were compared for wild-type (WT) seedlings and the nitrate reductase double mutant nia. Phosphate deprivation increased NO production in WT roots, and the AOX level and the capacity of the alternative pathway to consume electrons in WT seedlings; whereas the same treatment failed to stimulate NO production and AOX expression in the nia mutant, and the plants had an altered growth phenotype. The NO donor S-nitrosoglutathione rescued the growth phenotype of the nia mutants under phosphate deprivation to some extent, and it also increased the respiratory capacity of AOX. It is concluded that NO is required for the induction of the AOX pathway when seedlings are grown under phosphate-limiting conditions. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Sodium citrate blood contamination by K2 -ethylenediaminetetraacetic acid (EDTA): impact on routine coagulation testing.

PubMed

Lima-Oliveira, G; Salvagno, G L; Danese, E; Favaloro, E J; Guidi, G C; Lippi, G

2015-06-01

The potential cross-contamination of additives between primary blood tubes is a well-known problem during sample collection. The aim of this study was to assess the impact of citrated blood contamination with different amounts of dipotassium ethylenediaminetetraacetic (K2 EDTA blood) on activated partial thromboplastin time (APTT), prothrombin time (PT), and fibrinogen. Blood was collected from 15 ostensibly healthy volunteers into four 0.109 m citrate blood tubes followed by one K2 EDTA blood tube. The citrate tubes of each subject were pooled and divided in five aliquots. The whole blood of the K2 EDTA tube was then added in scalar amounts to autologous citrated blood aliquots, to obtain K2 EDTA contamination ranging from 0% to 43%, and thus mimic potential pre-analytical contamination. A statistically and clinically significant prolongation was observed for both APTT and PT between 29% and 43% K2 EDTA contamination, whereas the decrease of fibrinogen values became statistically and clinically significant at 43% K2 EDTA contamination. The results of this investigation show that contamination of citrated blood with as much as 29% of K2 EDTA blood generates a significant bias in results of routine clotting assays. This has serious implications for patient safety and management. © 2014 John Wiley & Sons Ltd.

Dysregulation of phosphate metabolism and conditions associated with phosphate toxicity

PubMed Central

Brown, Ronald B; Razzaque, Mohammed S

2015-01-01

Phosphate homeostasis is coordinated and regulated by complex cross-organ talk through delicate hormonal networks. Parathyroid hormone (PTH), secreted in response to low serum calcium, has an important role in maintaining phosphate homeostasis by influencing renal synthesis of 1,25-dihydroxyvitamin D, thereby increasing intestinal phosphate absorption. Moreover, PTH can increase phosphate efflux from bone and contribute to renal phosphate homeostasis through phosphaturic effects. In addition, PTH can induce skeletal synthesis of another potent phosphaturic hormone, fibroblast growth factor 23 (FGF23), which is able to inhibit renal tubular phosphate reabsorption, thereby increasing urinary phosphate excretion. FGF23 can also fine-tune vitamin D homeostasis by suppressing renal expression of 1-alpha hydroxylase (1α(OH)ase). This review briefly discusses how FGF23, by forming a bone–kidney axis, regulates phosphate homeostasis, and how its dysregulation can lead to phosphate toxicity that induces widespread tissue injury. We also provide evidence to explain how phosphate toxicity related to dietary phosphorus overload may facilitate incidence of noncommunicable diseases including kidney disease, cardiovascular disease, cancers and skeletal disorders. PMID:26131357

Aluminum and Fenton reaction: how can the reaction be modulated by speciation? A computational study using citrate as a test case.

PubMed

Mujika, Jon I; Dalla Torre, Gabriele; Lopez, Xabier

2018-06-13

The pro-oxidant ability of aluminum is behind many of the potential toxic effects of this exogenous element in the human organism. Although the overall process is still far from being understood at the molecular level, the well known ability of aluminum to promote the Fenton reaction is mediated through the formation of stable aluminum-superoxide radical complexes. However, the properties of metal complexes are highly influenced by the speciation of the metal. In this paper, we investigate the effect that speciation could have on the pro-oxidant activity of aluminum. We choose citrate as a test case, because it is the main low-molecular-mass chelator of aluminum in blood serum, forming very stable aluminum-citrate complexes. The influence of citrate in the interaction of aluminum with the superoxide radical is investigated, determining how the formation of aluminum-citrate complexes affects the promotion of the Fenton reaction. The results indicate that citrate increases the stability of the aluminum-superoxide complexes through the formation of ternary compounds, and that the Fenton reaction is even more favorable when aluminum is chelated to citrate. Nevertheless, our results demonstrate that overall, citrate may prevent the pro-oxidant activity of aluminum: on one hand, in an excess of citrate, the formation of 1 : 2 aluminum-citrate complexes is expected. On the other hand, the chelation of iron by citrate makes the reduction of iron thermodynamically unfavorable. In summary, the results suggest that citrate can have both a promotion and protective role, depending on subtle factors, such as initial concentration, non-equilibrium behavior and the exchange rate of ligands in the first shell of the metals.

Highly selective and sensitive macrocycle-based dinuclear foldamer for fluorometric and colorimetric sensing of citrate in water.

PubMed

Rhaman, Md Mhahabubur; Hasan, Mohammad H; Alamgir, Azmain; Xu, Lihua; Powell, Douglas R; Wong, Bryan M; Tandon, Ritesh; Hossain, Md Alamgir

2018-01-10

The selective detection of citrate anions is essential for various biological functions in living systems. A quantitative assessment of citrate is required for the diagnosis of various diseases in the human body; however, it is extremely challenging to develop efficient fluorescence and color-detecting molecular probes for sensing citrate in water. Herein, we report a macrocycle-based dinuclear foldamer (1) assembled with eosin Y (EY) that has been studied for anion binding by fluorescence and colorimetric techniques in water at neutral pH. Results from the fluorescence titrations reveal that the 1·EY ensemble strongly binds citrate anions, showing remarkable selectivity over a wide range of inorganic and carboxylate anions. The addition of citrate anions to the 1·EY adduct led to a large fluorescence enhancement, displaying a detectable color change under both visible and UV light in water up to 2 μmol. The biocompatibility of 1·EY as an intracellular carrier in a biological system was evaluated on primary human foreskin fibroblast (HF) cells, showing an excellent cell viability. The strong binding properties of the ensemble allow it to be used as a highly sensitive, detective probe for biologically relevant citrate anions in various applications.

Inhibitory effect of fentanyl citrate on the release of endothlin-1 induced by bradykinin in melanoma cells.

PubMed

Andoh, Tsugunobu; Shinohara, Akira; Kuraishi, Yasushi

2017-02-01

Our previous study showed that the μ-opioid receptor agonist fentanyl citrate inhibits endothelin-1-and bradykinin-mediated pain responses in mice orthotopically inoculated with melanoma cells. We also demonstrated that bradykinin induces endothelin-1 secretion in melanoma cells. However, the analgesic mechanisms of fentanyl citrate remain unclear. Thus, the present study was conducted to determine whether fentanyl citrate affects bradykinin-induced endothelin-1 secretion in B16-BL6 melanoma cells. The amount of endothelin-1 in the culture medium was measured using an enzyme immunoassay. The expression of endothelin-1, kinin B 2 receptors, and μ-opioid receptors in B16-BL/6 melanoma cells was determined using immunocytochemistry. Fentanyl citrate inhibited bradykinin-induced endothelin-1 secretion. The inhibitory effect of fentanyl citrate on the secretion of endothelin-1 was attenuated by the μ-opioid receptor antagonist naloxone methiodide. The immunoreactivities of endothelin-1, kinin B 2 receptors, and μ-opioid receptors in B16-BL6 melanoma cells were observed. These results suggest that fentanyl citrate regulates bradykinin-induced endothelin-1 secretion through μ-opioid receptors in melanoma cells. Copyright © 2016 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

21 CFR 172.370 - Iron-choline citrate complex.

Code of Federal Regulations, 2010 CFR

2010-04-01

....370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline...

Reduced glutathione and glutathione disulfide in the blood of glucose-6-phosphate dehydrogenase-deficient newborns.

PubMed

Gong, Zhen-Hua; Tian, Guo-Li; Huang, Qi-Wei; Wang, Yan-Min; Xu, Hong-Ping

2017-07-20

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is commonly detected during mass screening for neonatal disease. We developed a method to measure reduced glutathione (GSH) and glutathione disulfide (GSSG) using tandem mass spectrometry (MS/MS) for detecting G6PD deficiency. The concentration of GSH and the GSH/GSSG ratio in newborn dry-blood-spot (DBS) screening and in blood plus sodium citrate for test confirmation were examined by MS/MS using labeled glycine as an internal standard. G6PD-deficient newborns had a lower GSH content (242.9 ± 15.9 μmol/L)and GSH/GSSG ratio (14.9 ± 7.2) than neonatal controls (370.0 ± 53.2 μmol/L and 46.7 ± 19.6, respectively). Although the results showed a significance of P < 0.001 for DBS samples plus sodium citrate that were examined the first day after preparation, there were no significant differences in the mean GSH concentration and GSH/GSSG ratio between the G6PD deficiency-positive and negative groups when examined three days after sample preparation. The concentration of GSH and the ratio of GSH/GSSG in blood measured using MS/MS on the first day of sample preparation are consistent with G6PD activity and are helpful for diagnosing G6PD deficiency.

ATP-citrate lyase links cellular metabolism to histone acetylation.

PubMed

Wellen, Kathryn E; Hatzivassiliou, Georgia; Sachdeva, Uma M; Bui, Thi V; Cross, Justin R; Thompson, Craig B

2009-05-22

Histone acetylation in single-cell eukaryotes relies on acetyl coenzyme A (acetyl-CoA) synthetase enzymes that use acetate to produce acetyl-CoA. Metazoans, however, use glucose as their main carbon source and have exposure only to low concentrations of extracellular acetate. We have shown that histone acetylation in mammalian cells is dependent on adenosine triphosphate (ATP)-citrate lyase (ACL), the enzyme that converts glucose-derived citrate into acetyl-CoA. We found that ACL is required for increases in histone acetylation in response to growth factor stimulation and during differentiation, and that glucose availability can affect histone acetylation in an ACL-dependent manner. Together, these findings suggest that ACL activity is required to link growth factor-induced increases in nutrient metabolism to the regulation of histone acetylation and gene expression.

Magnesium flux during continuous venovenous haemodiafiltration with heparin and citrate anticoagulation.

PubMed

Brain, Matthew; Anderson, Mike; Parkes, Scott; Fowler, Peter

2012-12-01

To describe magnesium flux and serum concentrations in ICU patients receiving continuous venovenous haemodiafiltration (CVVHDF). Samples were collected from 22 CVVHDF circuits using citrate anticoagulation solutions (Prismocitrate 10/2 and Prism0cal) and from 26 circuits using Hemosol B0 and heparin anticoagulation. CVVHDF prescription, magnesium supplementation and anticoagulation choice was by the treating intensivist. We analysed 334 sample sets consisting of arterial, prefilter and postfilter blood and effluent. Magnesium loss was calculated from an equation for conservation of mass, and arterial magnesium concentration was described by an equation for exponential decay. Using flow rates typical of adults receiving CVVHDF, we determined a median half-life for arterial magnesium concentration to decay to a new steady state of 4.73 hours (interquartile range [IQR], 3.73-7.32 hours). Median arterial magnesium concentration was 0.88mmol/L (IQR, 0.83-0.97mmol/L) in the heparin group and 0.79mmol/L (IQR, 0.69-0.91mmol/L) in the citrate group. Arterial magnesium concentrations fell below the reference range regularly in the citrate group and, when low, there was magnesium flux from dialysate to patient. Magnesium loss was greater in patients receiving citrate. Exponential decline in magnesium concentrations was sufficiently rapid that subtherapeutic serum magnesium concentrations may occur well before detection when once-daily sampling was used. Measurements should be interpreted with regard to timing of magnesium infusions. We suggest that continuous renal replacement therapy fluids with higher magnesium concentrations be introduced in the critical care setting.

Optimized sildenafil citrate fast orodissolvable film: a promising formula for overcoming the barriers hindering erectile dysfunction treatment.

PubMed

Hosny, Khaled Mohamed; El-Say, Khalid Mohamed; Ahmed, Osama Abdelhakim

2016-01-01

Sildenafil citrate, a drug used to treat erectile dysfunction, is available in tablet form but has three major problems. First, the drug displays poor aqueous solubility, which delays its onset of action. Second, the drug undergoes extensive first-pass metabolism, resulting in a low (40%) bioavailability. Third, the gastrointestinal effects of sildenafil citrate include dyspepsia and a burning sensation. The objective of this study was to prepare sildenafil citrate using a fast orodissolvable film (ODF) containing the drug in a solid dispersion (SD) to mitigate the abovementioned problems. The solubility of sildenafil citrate in β-cyclodextrin derivatives was estimated, and SDs were prepared and characterized. To develop an ODF that disintegrates rapidly and releases the maximum amount of sildenafil citrate, a 3(3) Box-Behnken experimental design was used to estimate the effects of different concentrations of film forming polymer (X1), the film modifier (X2), and the plasticizer (X3) on the responses, i.e. the disintegration time (Y1) and the amount of drug released (Y2). Pharmacokinetic studies with the optimized (ODF) were conducted on human volunteers. SD prepared using hydroxybutyl-β-cyclodextrin enhanced the solubility of sildenafil citrate by more than eightfold. The Y1 for the optimized ODF was 89 seconds, and the Y2 was 86%; this formula also exhibited a rapid onset of action, and its bioavailability was enhanced by 2.25-fold compared with that of the marketed tablet. The ODF is a promising formulation for sildenafil citrate that results in higher solubility, a rapid onset of action, and enhanced systemic bioavailability.

Citrate metabolism in blood transfusions and its relationship due to metabolic alkalosis and respiratory acidosis

PubMed Central

Li, Kai; Xu, Yuan

2015-01-01

Metabolic alkalosis commonly results from excessive hydrochloric acid (HCl), potassium (K+) and water (H2O) loss from the stomach or through the urine. The plasma anion gap increases in non-hypoproteinemic metabolic alkalosis due to an increased negative charge equivalent on albumin and the free ionized calcium (Ca++) content of plasma decreases. The mean citrate load in all patients was 8740±7027 mg from 6937±6603 mL of transfused blood products. The citrate load was significantly higher in patients with alkalosis (9164±4870 vs. 7809±3967, P < 0.05). The estimated mean total citrate administered via blood and blood products was calculated as 43.2±34.19 mg/kilogram/day. In non-massive and frequent blood transfusions, the elevated carbon dioxide output has been shown to occur. Due to citrate metabolism causes intracellular acidosis. As a result of intracellular acidosis compensation, decompensated metabolic alkalosis + respiratory acidosis and electrolyte imbalance may develop, blood transfusions may result in certain complications. PMID:26131288

Citrate metabolism in blood transfusions and its relationship due to metabolic alkalosis and respiratory acidosis.

PubMed

Li, Kai; Xu, Yuan

2015-01-01

Metabolic alkalosis commonly results from excessive hydrochloric acid (HCl), potassium (K(+)) and water (H2O) loss from the stomach or through the urine. The plasma anion gap increases in non-hypoproteinemic metabolic alkalosis due to an increased negative charge equivalent on albumin and the free ionized calcium (Ca(++)) content of plasma decreases. The mean citrate load in all patients was 8740±7027 mg from 6937±6603 mL of transfused blood products. The citrate load was significantly higher in patients with alkalosis (9164±4870 vs. 7809±3967, P < 0.05). The estimated mean total citrate administered via blood and blood products was calculated as 43.2±34.19 mg/kilogram/day. In non-massive and frequent blood transfusions, the elevated carbon dioxide output has been shown to occur. Due to citrate metabolism causes intracellular acidosis. As a result of intracellular acidosis compensation, decompensated metabolic alkalosis + respiratory acidosis and electrolyte imbalance may develop, blood transfusions may result in certain complications.

Calcium citrate without aluminum antacids does not cause aluminum retention in patients with functioning kidneys

NASA Technical Reports Server (NTRS)

Sakhaee, K.; Wabner, C. L.; Zerwekh, J. E.; Copley, J. B.; Pak, L.; Poindexter, J. R.; Pak, C. Y.

1993-01-01

It has been suggested that calcium citrate might enhance aluminum absorption from food, posing a threat of aluminum toxicity even in patients with normal renal function. We therefore measured serum and urinary aluminum before and following calcium citrate therapy in patients with moderate renal failure and in normal subjects maintained on constant metabolic diets with known aluminum content (967-1034 mumol/day, or 26.1-27.9 mg/day, in patients and either 834 or 1579 mumol/day, or 22.5 and 42.6 mg/day, in normal subjects). Seven patients with moderate renal failure (endogenous creatinine clearance of 43 ml/min) took 50 mmol (2 g) calcium/day as effervescent calcium citrate with meals for 17 days. Eight normal women received 25 mmol (1 g) calcium/day as tricalcium dicitrate tablets with meals for 7 days. In patients with moderate renal failure, serum and urinary aluminum were normal before treatment at 489 +/- 293 SD nmol/l (13.2 +/- 7.9 micrograms/l) and 767 +/- 497 nmol/day (20.7 +/- 13.4 micrograms/day), respectively. They remained within normal limits and did not change significantly during calcium citrate treatment (400 +/- 148 nmol/l and 600 +/- 441 nmol/day, respectively). Similarly, no significant change in serum and urinary aluminum was detected in normal women during calcium citrate administration (271 +/- 59 vs 293 +/- 85 nmol/l and 515 +/- 138 vs 615 +/- 170 nmol/day, respectively). In addition, skeletal bone aluminum content did not change significantly in 14 osteoporotic patients (endogenous creatinine clearance of 68.5 ml/min) treated for 24 months with calcium citrate, 10 mmol calcium twice/day separately from meals (29.3 +/- 13.9 ng/mg ash bone to 27.9 +/0- 10.4, P = 0.727). In them, histomorphometric examination did not show any evidence of mineralization defect. Thus, calcium citrate given alone without aluminum-containing drugs does not pose a risk of aluminum toxicity in subjects with normal or functioning kidneys, when it is administered on an

Measurement of citrate in urine using liquid chromatography tandem mass spectrometry: comparison with an enzymatic method.

PubMed

Keevil, B G; Owen, L; Thornton, S; Kavanagh, J

2005-09-01

Measurement of urine citrate is used to assess the risk of further urinary stone formation and to assess the benefit of treatment in affected individuals. We wanted to develop a simple and rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the analysis of urinary citrate and to compare it with our current enzymatic assay. For the LC-MS/MS assay, samples were prepared in a deep-well block by adding 10 microL of urine and 20 microL of internal standard to 400 microL of water. After mixing, 3 microL of the diluted sample was injected into the LC-MS/MS system. An LC system was used to isocratically elute a C18 column (50 x 2.1 mm) with 0.4 mL/min water containing 2 mmol/L ammonium acetate and 0.1% (v/v) formic acid. A step gradient of 100% methanol containing 2 mmol/L ammonium acetate and 0.1% (v/v) formic acid was used to wash the column. The retention times were 1.4 min for citrate and 1.4 min for d4-citrate. Cycle time was 4.0 min, injection to injection. The analytes were monitored using a tandem mass spectrometer operated in multiple reaction monitoring mode using the following transitions, citrate m/z 191.0>111.0 and d4-citrate m/z 195.0>113.0. Within and between-batch coefficients of variation were <3% over the range 480-3800 micromol/L. The lower limit of quantification was 24.0 micromol/L. Regression analysis showed LC-MS/MS = 0.8781 (enzymatic assay) + 102.5, r = 0.964, n = 73. We have developed a simple LC-MS/MS method for urinary citrate measurement that shows acceptable performance.

Dissolution kinetics and biodurability of tremolite particles in mimicked lung fluids: Effect of citrate and oxalate

NASA Astrophysics Data System (ADS)

Rozalen, Marisa; Ramos, M. Elena; Huertas, F. Javier; Fiore, Saverio; Gervilla, Fernando

2013-11-01

The effect of citrate and oxalate on tremolite dissolution rate was measured at 37 °C in non-stirred flow-through reactors, using modified Gamble's solutions at pH 4 (macrophages), 7.4 (interstitial fluids) and 5.5 (intermediate check point) containing 0, 0.15, 1.5 and 15 mmol L-1 of citrate or oxalate. The dissolution rates calculated from Si concentration in the output solutions without organic ligands depend on pH, decreasing when the pH increases from -13.00 (pH 4) to -13.35 (pH 7.4) mol g-1 s-1 and following a proton-promoted mechanism. The presence of both ligands enhances dissolution rates at every pH, increasing this effect when the ligand concentration increases. Citrate produces a stronger effect as a catalyst than oxalate, mainly at more acidic pHs and enhances dissolution rates until 20 times for solutions with 15 mmol L-1 citrate. However, at pH 7.4 the effect is lighter and oxalate solutions (15 mmol L-1) only enhances dissolution rates eight times respect to free organic ligand solutions. Dissolution is promoted by the attack to protons and organic ligands to the tremolite surface. Magnesium speciation in oxalate and citrate solutions shows that Mg citrate complexes are more effective than oxalate ones during the alteration of tremolite in magrophages, but this tendency is the opposite for interstitial fluids, being oxalate magnesium complexes stronger. The biodurability estimations show that the destruction of the fibers is faster in acidic conditions (macrophages) than in the neutral solutions (interstitial fluid). At pH 4, both ligands oxalate and citrate reduce the residence time of the fibers with respect to that calculated in absence of ligands. Nevertheless, at pH 7.4 the presence of ligands does not reduce significantly the lifetime of the fibers.

Mechanism of Citrate Metabolism by an Oxaloacetate Decarboxylase-Deficient Mutant of Lactococcus lactis IL1403 ▿

PubMed Central

Pudlik, Agata M.; Lolkema, Juke S.

2011-01-01

Citrate metabolism in resting cells of Lactococcus lactis IL1403(pFL3) results in the formation of two end products from the intermediate pyruvate, acetoin and acetate (A. M. Pudlik and J. S. Lolkema, J. Bacteriol. 193:706–714, 2011). Pyruvate is formed from citrate following uptake by the transporter CitP through the subsequent actions of citrate lyase and oxaloacetate decarboxylase. The present study describes the metabolic response of L. lactis when oxaloacetate accumulates in the cytoplasm. The oxaloacetate decarboxylase-deficient mutant ILCitM(pFL3) showed nearly identical rates of citrate consumption, but the end product profile in the presence of glucose shifted from mainly acetoin to only acetate. In addition, in contrast to the parental strain, the mutant strain did not generate proton motive force. Citrate consumption by the mutant strain was coupled to the excretion of oxaloacetate, with a yield of 80 to 85%. Following citrate consumption, oxaloacetate was slowly taken up by the cells and converted to pyruvate by a cryptic decarboxylase and, subsequently, to acetate. The transport of oxaloacetate is catalyzed by CitP. The parental strain IL1403(pFL3) containing CitP consumed oxaloacetate, while the original strain, IL1403, not containing CitP, did not. Moreover, oxaloacetate consumption was enhanced in the presence of l-lactate, indicating exchange between oxaloacetate and l-lactate catalyzed by CitP. Hence, when oxaloacetate inadvertently accumulates in the cytoplasm, the physiological response of L. lactis is to excrete oxaloacetate in exchange with citrate by an electroneutral mechanism catalyzed by CitP. Subsequently, in a second step, oxaloacetate is taken up by CitP and metabolized to pyruvate and acetate. PMID:21665973

Textural and cargo release attributes of trisodium citrate cross-linked starch hydrogel.

PubMed

Abhari, Negar; Madadlou, Ashkan; Dini, Ali; Hosseini Naveh, Ozra

2017-01-01

An alkaline starch suspension was charged with citric acid and incubated for different durations (0, 8.5 or 17h). The suspension was then supplemented with caffeine and gelatinized to fabricate hydrogels which were subsequently stored for varying periods (0, 24 or 48h). Charging of the well-dissolved alkaline starch suspension with citric acid decreased at first both the flow index and consistency coefficient (K); however, starch cross-linking over time by the generated trisodium citrate increased the K value. The latter also inhibited gel syneresis and increased its water-holding capacity. Trisodium citrate did not nonetheless influence the gel hardness except for the sample incubated for maximum duration and stored for the longest period. The amount of the caffeine released from hydrogel decreased by citrate cross-linking and was higher at neutral pH than pH 2.0. Fourier-transform infra-red spectroscopy suggested that caffeine was enclosed within the gel network via non-covalent interactions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Revision of iron(III)-citrate speciation in aqueous solution. Voltammetric and spectrophotometric studies.

PubMed

Vukosav, Petra; Mlakar, Marina; Tomišić, Vladislav

2012-10-01

A detailed study of iron (III)-citrate speciation in aqueous solution (θ=25°C, I(c)=0.7 mol L(-1)) was carried out by voltammetric and UV-vis spectrophotometric measurements and the obtained data were used for reconciled characterization of iron (III)-citrate complexes. Four different redox processes were registered in the voltammograms: at 0.1 V (pH=5.5) which corresponded to the reduction of iron(III)-monocitrate species (Fe:cit=1:1), at about -0.1 V (pH=5.5) that was related to the reduction of FeL(2)(5-), FeL(2)H(4-) and FeL(2)H(2)(3-) complexes, at -0.28 V (pH=5.5) which corresponded to the reduction of polynuclear iron(III)-citrate complex(es), and at -0.4V (pH=7.5) which was probably a consequence of Fe(cit)(2)(OH)(x) species reduction. Reversible redox process at -0.1 V allowed for the determination of iron(III)-citrate species and their stability constants by analyzing E(p) vs. pH and E(p) vs. [L(4-)] dependence. The UV-vis spectra recorded at varied pH revealed four different spectrally active species: FeLH (logβ=25.69), FeL(2)H(2)(3-) (log β=48.06), FeL(2)H(4-) (log β=44.60), and FeL(2)(5-) (log β=38.85). The stability constants obtained by spectrophotometry were in agreement with those determined electrochemically. The UV-vis spectra recorded at various citrate concentrations (pH=2.0) supported the results of spectrophotometric-potentiometric titration. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of sildenafil citrate on endometrial preparation and outcome of frozen-thawed embryo transfer cycles: a randomized clinical trial.

PubMed

Dehghani Firouzabadi, Razieh; Davar, Robab; Hojjat, Farzaneh; Mahdavi, Mohamad

2013-02-01

Sildenafil citrate may increase endometrial thickness and affect the outcome of frozen-thawed embryo transfer cycles. The aim of this study was to estimate the effect of sildenafil citrate on ultrasonographic endometrial thickness and pattern and to investigate the estrogen level on the day of progesterone administration, the implantation rate and chemical pregnancy rate in frozen embryo transfer cycles. This randomized controlled trial was conducted on 80 patients who had an antecedent of poor endometrial response and frozen embryos. 40 patients were given estradiol by a step up method with menstruation to prepare the endometrium, and the other 40 were given sildenafil citrate tablets (50 mg) daily in addition to the above treatment protocol from the first day of the cycle until the day progesterone was started. This was discontinued 48-72 hours prior to the embryo transfer. The endometrial thickness was significantly higher in the sildenafil citrate group (p<0.0001), the triple line patterns of the endometrium were significantly higher in the sildenafil citrate group (p<0.0001), while the intermediate patterns of the endometrium were not significantly different in the two groups. The echogen patterns of the endometrium were significantly higher in control group (p<0.0001). Finally, implantation rate and the chemical pregnancy rates were higher in the sildenafil citrate group but not significantly. As our study shows, the oral use of sildenafil citrate is a good way to improve the endometrial receptivity. We recommend the routine use of oral sildenafil citrate in patients with a previous failure of assisted reproduction technology cycles due to poor endometrial thickness.

A randomised study to compare salivary pH, calcium, phosphate and calculus formation after using anticavity dentifrices containing Recaldent(®) and functionalized tri-calcium phosphate.

PubMed

Sharma, Ena; Vishwanathamurthy, Ramesh Alampalli; Nadella, Manjari; Savitha, A N; Gundannavar, Gayatri; Hussain, M Ahad

2012-10-01

The aim of this study was to estimate the pH of saliva, concentration of calcium and inorganic phosphate, and calculus formation before and after usage of Recaldent(®) (GC Tooth Mousse Plus™), Functionalized Tricalcium Phosphate (3M ESPE ClinPro™ Tooth Crème) and standard dentifrice (Colgate dental cream). Randomized double-blind study. A total of 50 subjects were recruited, the subjects were assessed at their first visit, on the 21(st) day and on the 42(nd) day. At the first visit, scaling was carried out and oral hygiene instructions were given. After 21 days, the subjects were given coded dentifrices where the operator and the subjects both were unaware of the type of dentifrice. Clinical parameters assessed were Plaque index, Gingival index, and Calculus index. Salivary samples were obtained to measure calcium, phosphate levels, and pH at 21(st) day and 42(nd) day. ANOVA test, t-test, Mann-Whitney test, Kruskal-Wallis test. The mean salivary calcium level and mean salivary phosphate level were higher in Group III (functionalized tricalcium phosphate (3M ESPE ClinPro™ Tooth Creme) as compared to Group II (Recaldent(®) GC Tooth Mousse Plus™) and Group I (Colgate dental cream) on the 42(nd) day after using dentifrices, which was statistically significant. This showed that the usage of remineralizing dentifrices led to an increase in the salivary calcium, phosphate, and pH but it did not reach the level of super saturation of the ions caused by elevated pH which could lead to calculus formation. Thought here was a statistically significant increase in salivary calcium and phosphate level in all three groups from baseline to 42(nd) day, there was no calculus formation.

Inorganic phosphate blocks binding of pre-miRNA to Dicer-2 via its PAZ domain

PubMed Central

Fukunaga, Ryuya; Colpan, Cansu; Han, Bo W; Zamore, Phillip D

2014-01-01

In Drosophila, Dicer-1 produces microRNAs (miRNAs) from pre-miRNAs, whereas Dicer-2 generates small interfering RNAs from long double-stranded RNA (dsRNA), a process that requires ATP hydrolysis. We previously showed that inorganic phosphate inhibits Dicer-2 cleavage of pre-miRNAs, but not long dsRNAs. Here, we report that phosphate-dependent substrate discrimination by Dicer-2 reflects dsRNA substrate length. Efficient processing by Dicer-2 of short dsRNA requires a 5′ terminal phosphate and a two-nucleotide, 3′ overhang, but does not require ATP. Phosphate inhibits cleavage of such short substrates. In contrast, cleavage of longer dsRNA requires ATP but no specific end structure: phosphate does not inhibit cleavage of these substrates. Mutation of a pair of conserved arginine residues in the Dicer-2 PAZ domain blocked cleavage of short, but not long, dsRNA. We propose that inorganic phosphate occupies a PAZ domain pocket required to bind the 5′ terminal phosphate of short substrates, blocking their use and restricting pre-miRNA processing in flies to Dicer-1. Our study helps explain how a small molecule can alter the substrate specificity of a nucleic acid processing enzyme. PMID:24488111

Bright luminescence of Vibrio fischeri aconitase mutants reveals a connection between citrate and the Gac/Csr regulatory system.

PubMed

Septer, Alecia N; Bose, Jeffrey L; Lipzen, Anna; Martin, Joel; Whistler, Cheryl; Stabb, Eric V

2015-01-01

The Gac/Csr regulatory system is conserved throughout the γ-proteobacteria and controls key pathways in central carbon metabolism, quorum sensing, biofilm formation and virulence in important plant and animal pathogens. Here we show that elevated intracellular citrate levels in a Vibrio fischeri aconitase mutant correlate with activation of the Gac/Csr cascade and induction of bright luminescence. Spontaneous or directed mutations in the gene that encodes citrate synthase reversed the bright luminescence of aconitase mutants, eliminated their citrate accumulation and reversed their elevated expression of CsrB. Our data elucidate a correlative link between central metabolic and regulatory pathways, and they suggest that the Gac system senses a blockage at the aconitase step of the tricarboxylic acid cycle, either through elevated citrate levels or a secondary metabolic effect of citrate accumulation, and responds by modulating carbon flow and various functions associated with host colonization, including bioluminescence. © 2014 John Wiley & Sons Ltd.

Bowel preparations for capsule endoscopy: a comparison between simethicone and magnesium citrate.

PubMed

Esaki, Motohiro; Matsumoto, Takayuki; Kudo, Tetsuji; Yanaru-Fujisawa, Ritsuko; Nakamura, Shotaro; Iida, Mitsuo

2009-01-01

Bowel preparation for capsule endoscopy (CE) has not been standardized. This study aimed to compare CE images between patients prepared by simethicone and those prepared by magnesium citrate. Retrospective analysis of case series of our hospital from 2004 to 2007. Single center. CE images of 75 patients receiving bowel preparation either by 200 mg of simethicone (n=39) or by 34 g of magnesium citrate (n=36) were retrospectively investigated. Grades of fluid transparency and mucosal invisibility by air bubbles and food residue were compared between the 2 preparations. Capsule transit time, frequency of positive findings, and interobserver variations between 2 observers were also investigated. Image quality and diagnostic yield of CE. Fluid transparency in the first and the third time segments of the small intestine was better in patients prepared by magnesium citrate than in those prepared by simethicone (P= .001 and P= .03, respectively). On the other hand, mucosal invisibility was not different in any part of the small intestine between the 2 groups. Neither gastric transit time nor small-bowel transit time was different between the 2 groups. The diagnostic yield of CE correlated significantly with fluid transparency (P= .04), but it did not correlate with mucosal invisibility. Single-center retrospective study. Magnesium citrate seems to be a recommended preparation for CE compared with simethicone. The fluid transparency, rather than the mucosal invisibility, may be a factor associated with the diagnostic yield of CE.

Determination and analysis of site-specific 125I decay-induced DNA double-strand break end-group structures.

PubMed

Datta, Kamal; Weinfeld, Michael; Neumann, Ronald D; Winters, Thomas A

2007-02-01

End groups contribute to the structural complexity of radiation-induced DNA double-strand breaks (DSBs). As such, end-group structures may affect a cell's ability to repair DSBs. The 3'-end groups of strand breaks caused by gamma radiation, or oxidative processes, under oxygenated aqueous conditions have been shown to be distributed primarily between 3'-phosphoglycolate and 3'-phosphate, with 5'-phosphate ends in both cases. In this study, end groups of the high-LET-like DSBs caused by 125I decay were investigated. Site-specific DNA double-strand breaks were produced in plasmid pTC27 in the presence or absence of 2 M DMSO by 125I-labeled triplex-forming oligonucleotide targeting. End-group structure was assessed enzymatically as a function of the DSB end to serve as a substrate for ligation and various forms of end labeling. Using this approach, we have demonstrated 3'-hydroxyl (3'-OH) and 3'-phosphate (3'-P) end groups and 5'-ends (> or = 42%) terminated by phosphate. A 32P postlabeling assay failed to detect 3'-phosphoglycolate in a restriction fragment terminated by the 125I-induced DNA double-strand break, and this is likely due to restricted oxygen diffusion during irradiation as a frozen aqueous solution. Even so, end-group structure and relative distribution varied as a function of the free radical scavenging capacity of the irradiation buffer.

Is magnesium citrate treatment effective on pain, clinical parameters and functional status in patients with fibromyalgia?

PubMed

Bagis, Selda; Karabiber, Mehmet; As, Ismet; Tamer, Lülüfer; Erdogan, Canan; Atalay, Ayçe

2013-01-01

The aims of this study were to investigate the relationship between magnesium levels and fibromyalgia symptoms and to determine the effect of magnesium citrate treatment on these symptoms. Sixty premenopausal women diagnosed with fibromyalgia according to the ACR criteria and 20 healthy women whose age and weight matched the premenopausal women were evaluated. Pain intensity, pain threshold, the number of tender points, the tender point index, the fibromyalgia impact questionnaire (FIQ), the Beck depression and Beck anxiety scores and patient symptoms were evaluated in all the women. Serum and erythrocyte magnesium levels were also measured. The patients were divided into three groups. The magnesium citrate (300 mg/day) was given to the first group (n = 20), amitriptyline (10 mg/day) was given to the second group (n = 20), and magnesium citrate (300 mg/day) + amitriptyline (10 mg/day) treatment was given to the third group (n = 20). All parameters were reevaluated after the 8 weeks of treatment. The serum and erythrocyte magnesium levels were significantly lower in patients with fibromyalgia than in the controls. Also there was a negative correlation between the magnesium levels and fibromyalgia symptoms. The number of tender points, tender point index, FIQ and Beck depression scores decreased significantly with the magnesium citrate treatment. The combined amitriptyline + magnesium citrate treatment proved effective on all parameters except numbness. Low magnesium levels in the erythrocyte might be an etiologic factor on fibromyalgia symptoms. The magnesium citrate treatment was only effective tender points and the intensity of fibromyalgia. However, it was effective on all parameters when used in combination with amitriptyline.

Involvement of CitCHX and CitDIC in Developmental-Related and Postharvest-Hot-Air Driven Citrate Degradation in Citrus Fruits

PubMed Central

Lin, Qiong; Li, Shaojia; Dong, Wencheng; Feng, Chao; Yin, Xueren; Xu, Changjie; Sun, Chongde; Chen, Kunsong

2015-01-01

Citrate is the predominant organic acid associated with taste in citrus fruit. Although citrate metabolism has been widely studied in recent years, the potential contributions of transport proteins to citrate content remain unclear. In the present study, high-acid citrus fruit Gaocheng (‘GC’, Citrus sp.) and low-acid citrus fruit Satsuma mandarin (‘SM’, Citrus unshiu Marc.) were selected for study, and the degradation of citrate was deduced to be the main cause of the difference in acidity in fully mature fruits. RNA-seq analysis was carried out on ‘GC’ and ‘SM’ fruit samples over the same time course, and the results indicated that citrate degradation occurred mainly through the glutamine pathway, catalyzed by CitAco3-CitGS2-CitGDU1, and also two transport-related genes, CitCHX and CitDIC, were shown to be associated with citrate degradation. These results were confirmed by real-time PCR. In postharvest ‘GC’ fruit, the expressions of these two transport-related genes were induced by 2-fold under hot air treatment, accompanied by a reduction of 7%-9% in total acid degradation. Transient expression of CitCHX and CitDIC in tobacco leaves was performed, and the citrate content was reduced by 62%, 75% and 78% following CitCHX, CitDIC and CitCHX plus CitDIC treatments, respectively, as compared with expression of an empty vector. Overall, these data indicated that two transport proteins, CitCHX and CitDIC, are not only involved in citrate degradation during fruit development, but also involved in postharvest hot air triggered citrate reduction. PMID:25738939

Interaction between Nitrogen and Phosphate Stress Responses in Sinorhizobium meliloti

DOE PAGES

Hagberg, Kelly L.; Yurgel, Svetlana N.; Mulder, Monika; ...

2016-11-30

Bacteria have developed various stress response pathways to improve their assimilation and allocation of limited nutrients, such as nitrogen and phosphate. While both the nitrogen stress response (NSR) and phosphate stress response (PSR) have been studied individually, there are few experiments reported that characterize effects of multiple stresses on one or more pathways in Sinorhizobium meliloti, a facultatively symbiotic, nitrogen-fixing bacteria. The PII proteins, GlnB and GlnK, regulate the NSR activity, but analysis of global transcription changes in a PII deficient mutant suggest that the S. meliloti PII proteins may also regulate the PSR. PII double deletion mutants grow verymore » slowly and pseudoreversion of the slow growth phenotype is common. In order to understand this phenomenon better, transposon mutants were isolated that had a faster growing phenotype. One mutation was in phoB, the response regulator for a two component regulatory system that is important in the PSR. phoB::Tn5 mutants had different phenotypes in the wild type compared to a PII deficient background. This led to the hypothesis that phosphate stress affects the NSR and conversely, that nitrogen stress affects the PSR. These results show that phosphate availability affects glutamine synthetase activity and expression, which are often used as indicators of NSR activity, but that nitrogen availability did not affect alkaline phosphatase activity and expression, which are indicators of PSR activity. Finally, we conclude that the NSR is co-regulated by nitrogen and phosphate, whereas the PSR does not appear to be co-regulated by nitrogen in addition to its known phosphate regulation.« less

Interaction between Nitrogen and Phosphate Stress Responses in Sinorhizobium meliloti

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hagberg, Kelly L.; Yurgel, Svetlana N.; Mulder, Monika

Bacteria have developed various stress response pathways to improve their assimilation and allocation of limited nutrients, such as nitrogen and phosphate. While both the nitrogen stress response (NSR) and phosphate stress response (PSR) have been studied individually, there are few experiments reported that characterize effects of multiple stresses on one or more pathways in Sinorhizobium meliloti, a facultatively symbiotic, nitrogen-fixing bacteria. The PII proteins, GlnB and GlnK, regulate the NSR activity, but analysis of global transcription changes in a PII deficient mutant suggest that the S. meliloti PII proteins may also regulate the PSR. PII double deletion mutants grow verymore » slowly and pseudoreversion of the slow growth phenotype is common. In order to understand this phenomenon better, transposon mutants were isolated that had a faster growing phenotype. One mutation was in phoB, the response regulator for a two component regulatory system that is important in the PSR. phoB::Tn5 mutants had different phenotypes in the wild type compared to a PII deficient background. This led to the hypothesis that phosphate stress affects the NSR and conversely, that nitrogen stress affects the PSR. These results show that phosphate availability affects glutamine synthetase activity and expression, which are often used as indicators of NSR activity, but that nitrogen availability did not affect alkaline phosphatase activity and expression, which are indicators of PSR activity. Finally, we conclude that the NSR is co-regulated by nitrogen and phosphate, whereas the PSR does not appear to be co-regulated by nitrogen in addition to its known phosphate regulation.« less

Trisodium citrate, Na 3 (C 6 H 5 O 7 )

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rammohan, Alagappa; Kaduk, James A.

2016-05-10

The crystal structure of anhydrous trisodium citrate, Na 3(C 6H 5O 7), has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory (DFT). There are two independent five-coordinate Na +and one six-coordinate Na +cations in the asymmetric unit. The [NaO 5] and [NaO 6] polyhedra share edges and corners to form a three-dimensional framework. There are channels parallel to theaandbaxes in which the remainder of the citrate anions reside. The only hydrogen bonds are an intramolecular one between the hydroxy group and one of the terminal carboxylate O atoms and an intermolecular onemore » between a methylene group and the hydroxyl O atom.« less

Adaptive responses of GLUT-4 and citrate synthase in fast-twitch muscle of voluntary running rats

NASA Technical Reports Server (NTRS)

Henriksen, E. J.; Halseth, A. E.

1995-01-01

Glucose transporter (GLUT-4) protein, hexokinase, and citrate synthase (proteins involved in oxidative energy production from blood glucose catabolism) increase in response to chronically elevated neuromuscular activity. It is currently unclear whether these proteins increase in a coordinated manner in response to this stimulus. Therefore, voluntary wheel running (WR) was used to chronically overload the fast-twitch rat plantaris muscle and the myocardium, and the early time courses of adaptative responses of GLUT-4 protein and the activities of hexokinase and citrate synthase were characterized and compared. Plantaris hexokinase activity increased 51% after just 1 wk of WR, whereas GLUT-4 and citrate synthase were increased by 51 and 40%, respectively, only after 2 wk of WR. All three variables remained comparably elevated (+50-64%) through 4 wk of WR. Despite the overload of the myocardium with this protocol, no substantial elevations in these variables were observed. These findings are consistent with a coordinated upregulation of GLUT-4 and citrate synthase in the fast-twitch plantaris, but not in the myocardium, in response to this increased neuromuscular activity. Regulation of hexokinase in fast-twitch muscle appears to be uncoupled from regulation of GLUT-4 and citrate synthase, as increases in the former are detectable well before increases in the latter.

Developmental toxicity of orally administered sildenafil citrate (Viagra) in SWR/J mice

PubMed Central

Abou-Tarboush, Faisal Mohamed; Abdel-Samad, Mohamed Fathy; Al-Meteri, Mokhlid Hamed

2010-01-01

Normal adult inbred SWR/J mice were used to investigate the teratogenic and other possible toxic effects of various dose levels of sildenafil citrate (Viagra) on fetuses. Multiple dose levels of 6.5, 13.0, 19.5, 26.0, 32.5 or 40.0 mg of sildenafil citrate/kg body weight (which correspond to the multiples of 1, 2, 3, 4, 5 or 6 of human 50 mg Viagra, respectively) were orally administered into pregnant mice on days 7–9, 10–12 or 13–15 of gestation. On day 17 of pregnancy, all fetuses were removed and examined for toxic phenomena (embryo-fetal toxicity) and for external, internal and skeletal malformations. A total of 285 pregnant mice were used in the present study. None of the dams treated with sildenafil citrate at any of the oral dose levels used in the present study died during the experimental period and all dams treated with the drug failed to reveal overt signs of maternal toxicity. Moreover, the results of the present study clearly demonstrate that none of the multiple oral dose levels of the drug at any time interval used has induced any external, internal or skeletal malformations in the fetuses obtained from treated females. However, the dose level of 40 mg/kg body weight of sildenafil citrate has a growth suppressing effect on alive fetuses when it was administered at all the time intervals used in the present study. Furthermore, the dose levels 26.0, 32.5 and 40 mg/kg of the drug have embryo-fetal toxicity when the drug is applied on days 13–15 of gestation. The possible mechanisms involved in the embryo-fetal toxicity and fetal growth suppressing effects of sildenafil citrate were discussed. The results of this study have important implications for the widespread use of this drug. PMID:23961116

Developmental toxicity of orally administered sildenafil citrate (Viagra) in SWR/J mice.

PubMed

Abou-Tarboush, Faisal Mohamed; Abdel-Samad, Mohamed Fathy; Al-Meteri, Mokhlid Hamed

2011-04-01

Normal adult inbred SWR/J mice were used to investigate the teratogenic and other possible toxic effects of various dose levels of sildenafil citrate (Viagra) on fetuses. Multiple dose levels of 6.5, 13.0, 19.5, 26.0, 32.5 or 40.0 mg of sildenafil citrate/kg body weight (which correspond to the multiples of 1, 2, 3, 4, 5 or 6 of human 50 mg Viagra, respectively) were orally administered into pregnant mice on days 7-9, 10-12 or 13-15 of gestation. On day 17 of pregnancy, all fetuses were removed and examined for toxic phenomena (embryo-fetal toxicity) and for external, internal and skeletal malformations. A total of 285 pregnant mice were used in the present study. None of the dams treated with sildenafil citrate at any of the oral dose levels used in the present study died during the experimental period and all dams treated with the drug failed to reveal overt signs of maternal toxicity. Moreover, the results of the present study clearly demonstrate that none of the multiple oral dose levels of the drug at any time interval used has induced any external, internal or skeletal malformations in the fetuses obtained from treated females. However, the dose level of 40 mg/kg body weight of sildenafil citrate has a growth suppressing effect on alive fetuses when it was administered at all the time intervals used in the present study. Furthermore, the dose levels 26.0, 32.5 and 40 mg/kg of the drug have embryo-fetal toxicity when the drug is applied on days 13-15 of gestation. The possible mechanisms involved in the embryo-fetal toxicity and fetal growth suppressing effects of sildenafil citrate were discussed. The results of this study have important implications for the widespread use of this drug.

Luteal Phase Support in the Intrauterine Insemination (IUI) Cycles: A Randomized Double Blind, Placebo Controlled Study

PubMed Central

Hossein Rashidi, Batool; Davari Tanha, Fatemeh; Rahmanpour, Haleh; Ghazizadeh, Mahya

2014-01-01

Objective: To evaluate the impact of luteal phase support with vaginal progesterone on pregnancy rates in the intrauterine insemination (IUI) cycles, stimulated with clomiphene citrate and human menopausal gonadotropin (hMG), in sub fertile couples. Materials and methods: This prospective, randomized, double blind study was performed in a tertiary infertility center from March 2011 to January 2012. It consisted of 253 sub fertile couples undergoing ovarian stimulation for IUI cycles. They underwent ovarian stimulation with clomiphene citrate (100 mg) and hMG (75 IU) in preparation for the IUI cycle. Study group (n = 127) received luteal phase support in the form of vaginal progesterone (400 mg twice a day), and control group (n = 126) received placebo. Clinical pregnancy and abortion rates were assessed and compared between the two groups. Results: The clinical pregnancy rate was not significantly higher for supported cycles than that for the unsupported ones (15.75% vs. 12.69%, p = 0.3). The abortion rate in the patients with progesterone luteal support compared to placebo group was not statistically different (10% vs. 18.75%, p = 0.45). Conclusion: It seems that luteal phase support with vaginal progesterone was not enhanced the success of IUI cycles outcomes, when clomiphene citrate and hMG were used for ovulation stimulation. PMID:25530766

An excess of topical calcium and magnesium reverses the therapeutic effect of citrate on the development of corneal ulcers after alkali injury.

PubMed

Haddox, J L; Pfister, R R; Slaughter, S E

1996-03-01

Our purpose was to determine whether chelation of Ca2+ and Mg2+ is the mechanism by which sodium citrate inhibits corneal ulceration in the alkali-injured rabbit eye. The right eyes of 60 albino rabbits (2-2.5 kg) were alkali-injured by filling a 12-mm-diameter plastic well placed on the corneal surface with 0.4 ml of 1 N NaOH. After 35 s the alkali was aspirated, and the well was rinsed with physiological saline. Animals were randomly distributed to three treatment groups of equal size. Two drops of the following topical medications were administered on the hour (14 times per day) for 35 days: physiological saline, 10% citrate in saline, and 346 mM Ca2+, 346 mM Mg2+, and 10% citrate in saline. During the experiment, significantly fewer ulcerations occurred in the citrate-treated eyes (five of 20, 25%) than in the saline-treated eyes (13 of 20, 65%) or in the calcium-magnesium-citrate-treated eyes (15 of 20, 75%). When ulcerations did develop in the citrate group, they occurred significantly later and were less severe than those in the saline and calcium-magnesium-citrate groups. There was a significant increase in the number of eyes with signs of band keratopathy and translucent areas in the calcium-magnesium-citrate group when compared with the other two groups. As in previous studies, sodium citrate significantly inhibited the development of corneal ulcers after alkali injury. The annullment of the favorable effect of citrate on ulceration in the alkali-injured eye by the addition of calcium and magnesium shows that the mechanism of action of citrate is the chelation of these divalent cations.

Phosphate Solubilization and Gene Expression of Phosphate-Solubilizing Bacterium Burkholderia multivorans WS-FJ9 under Different Levels of Soluble Phosphate.

PubMed

Zeng, Qingwei; Wu, Xiaoqin; Wang, Jiangchuan; Ding, Xiaolei

2017-04-28

Phosphate-solubilizing bacteria (PSB) have the ability to dissolve insoluble phosphate and enhance soil fertility. However, the growth and mineral phosphate solubilization of PSB could be affected by exogenous soluble phosphate and the mechanism has not been fully understood. In the present study, the growth and mineral phosphate-solubilizing characteristics of PSB strain Burkholderia multivorans WS-FJ9 were investigated at six levels of exogenous soluble phosphate (0, 0.5, 1, 5, 10, and 20 mM). The WS-FJ9 strain showed better growth at high levels of soluble phosphate. The phosphate-solubilizing activity of WS-FJ9 was reduced as the soluble phosphate concentration increased, as well as the production of pyruvic acid. Transcriptome profiling of WS-FJ9 at three levels of exogenous soluble phosphate (0, 5, and 20 mM) identified 446 differentially expressed genes, among which 44 genes were continuously up-regulated when soluble phosphate concentration was increased and 81 genes were continuously down-regulated. Some genes related to cell growth were continuously up-regulated, which would account for the better growth of WS-FJ9 at high levels of soluble phosphate. Genes involved in glucose metabolism, including glycerate kinase, 2-oxoglutarate dehydrogenase, and sugar ABC-type transporter, were continuously down-regulated, which indicates that metabolic channeling of glucose towards the phosphorylative pathway was negatively regulated by soluble phosphate. These findings represent an important first step in understanding the molecular mechanisms of soluble phosphate effects on the growth and mineral phosphate solubilization of PSB.

Beliefs and social norms about sildenafil citrate (Viagra) misuse and perceived consequences among Houstonian teenage males.

PubMed

Peters, Ronald J; Johnson, Regina J; Kelder, Steve; Meshack, Angela F; Jefferson, Troy

2007-09-01

In the current study, a qualitative approach was used to investigate relevant beliefs and norms associated with sildenafil citrate (Viagra) consumption, initiation, and perceived consequences. Focus groups were conducted with 43 young men aged 18 and 19 years who identified themselves as lifetime sildenafil citrate users. The majority of focus group participants believed that "curiosity" and "peer pressure" contributed to their initial use. Most revealed that they first heard about sildenafil citrate from television advertisements, family members, friends, or sporting events, and they were able to obtain the drug from their friends and family members or they stole it from their father or grandfather. These findings may highlight the relative importance of exposure to prescription drug messages among those to whom the message is not specifically targeted, that is, young men. It is possible that the sildenafil citrate television messages are recalled by not only older male audiences but also by teenagers and younger men, producing similar cognitive processing and curiosity in both age cohorts.

Development of transgenic pigeonpea (Cajanus cajan. L Millsp) overexpressing citrate synthase gene for high phosphorus uptake.

PubMed

Aftab Hussain, Aftab; Pavithra, I S; Sreevathsa, Rohini; Nataraja, K N; Babu, Naveen

2016-08-01

Plants have developed several adaptive strategies to enhance the availability and uptake of phosphorus (P) from the soil under conditions of P deficiency. Exudation of organic acids like citrate is one of the important strategies. In this study, we developed transgenic pigeonpea (Cajanus cajan) over-expressing Dacus carota citrate synthase (DcCs) gene to increase the synthesis and exudation of citrate. Transgenic plants were generated through agro bacterium mediated in-planta transformation technique. Integration and expression of the transgene was confirmed by genomic Southern and RT-PCR analysis. We observed that the transgenic lines had more tissue P and chlorophyll content, and also citrate synthase content higher in the roots. Further, transgenic lines had more vigorous root system both under P sufficient and deficient conditions with more lateral roots and root hairs under P deficient conditions. We conclude that the transgenic pigeonpea plants have the capacity to acquire more P under P deficient conditions.

Differentiating phosphate-dependent and phosphate-independent systemic phosphate-starvation response networks in Arabidopsis thaliana through the application of phosphite

PubMed Central

Jost, Ricarda; Pharmawati, Made; Lapis-Gaza, Hazel R.; Rossig, Claudia; Berkowitz, Oliver; Lambers, Hans; Finnegan, Patrick M.

2015-01-01

Phosphite is a less oxidized form of phosphorus than phosphate. Phosphite is considered to be taken up by the plant through phosphate transporters. It can mimic phosphate to some extent, but it is not metabolized into organophosphates. Phosphite could therefore interfere with phosphorus signalling networks. Typical physiological and transcriptional responses to low phosphate availability were investigated and the short-term kinetics of their reversion by phosphite, compared with phosphate, were determined in both roots and shoots of Arabidopsis thaliana. Phosphite treatment resulted in a strong growth arrest. It mimicked phosphate in causing a reduction in leaf anthocyanins and in the expression of a subset of the phosphate-starvation-responsive genes. However, the kinetics of the response were slower than for phosphate, which may be due to discrimination against phosphite by phosphate transporters PHT1;8 and PHT1;9 causing delayed shoot accumulation of phosphite. Transcripts encoding PHT1;7, lipid-remodelling enzymes such as SQD2, and phosphocholine-producing NMT3 were highly responsive to phosphite, suggesting their regulation by a direct phosphate-sensing network. Genes encoding components associated with the ‘PHO regulon’ in plants, such as At4, IPS1, and PHO1;H1, generally responded more slowly to phosphite than to phosphate, except for SPX1 in roots and MIR399d in shoots. Two uncharacterized phosphate-responsive E3 ligase genes, PUB35 and C3HC4, were also highly phosphite responsive. These results show that phosphite is a valuable tool to identify network components directly responsive to phosphate. PMID:25697796

21 CFR 520.622b - Diethylcarbamazine citrate syrup.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Diethylcarbamazine citrate syrup. 520.622b Section 520.622b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622b...

21 CFR 520.622b - Diethylcarbamazine citrate syrup.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Diethylcarbamazine citrate syrup. 520.622b Section 520.622b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622b...

21 CFR 520.622a - Diethylcarbamazine citrate tablets.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Diethylcarbamazine citrate tablets. 520.622a Section 520.622a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622a...

21 CFR 520.622a - Diethylcarbamazine citrate tablets.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Diethylcarbamazine citrate tablets. 520.622a Section 520.622a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622a...

21 CFR 520.622a - Diethylcarbamazine citrate tablets.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Diethylcarbamazine citrate tablets. 520.622a Section 520.622a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622a...

21 CFR 520.622b - Diethylcarbamazine citrate syrup.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Diethylcarbamazine citrate syrup. 520.622b Section 520.622b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622b...

21 CFR 520.622a - Diethylcarbamazine citrate tablets.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Diethylcarbamazine citrate tablets. 520.622a Section 520.622a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622a...

21 CFR 520.622d - Diethylcarbamazine citrate capsules.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Diethylcarbamazine citrate capsules. 520.622d Section 520.622d Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622d...

21 CFR 520.622d - Diethylcarbamazine citrate capsules.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Diethylcarbamazine citrate capsules. 520.622d Section 520.622d Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622d...

21 CFR 520.622d - Diethylcarbamazine citrate capsules.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Diethylcarbamazine citrate capsules. 520.622d Section 520.622d Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622d...

21 CFR 520.622b - Diethylcarbamazine citrate syrup.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Diethylcarbamazine citrate syrup. 520.622b Section 520.622b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622b...

21 CFR 520.622b - Diethylcarbamazine citrate syrup.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Diethylcarbamazine citrate syrup. 520.622b Section 520.622b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622b...

21 CFR 520.622d - Diethylcarbamazine citrate capsules.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Diethylcarbamazine citrate capsules. 520.622d Section 520.622d Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622d...

Citrate Accumulation-Related Gene Expression and/or Enzyme Activity Analysis Combined With Metabolomics Provide a Novel Insight for an Orange Mutant

PubMed Central

Guo, Ling-Xia; Shi, Cai-Yun; Liu, Xiao; Ning, Dong-Yuan; Jing, Long-Fei; Yang, Huan; Liu, Yong-Zhong

2016-01-01

‘Hong Anliu’ (HAL, Citrus sinensis cv. Hong Anliu) is a bud mutant of ‘Anliu’ (AL), characterized by a comprehensive metabolite alteration, such as lower accumulation of citrate, high accumulation of lycopene and soluble sugars in fruit juice sacs. Due to carboxylic acid metabolism connects other metabolite biosynthesis and/or catabolism networks, we therefore focused analyzing citrate accumulation-related gene expression profiles and/or enzyme activities, along with metabolic fingerprinting between ‘HAL’ and ‘AL’. Compared with ‘AL’, the transcript levels of citrate biosynthesis- and utilization-related genes and/or the activities of their respective enzymes such as citrate synthase, cytosol aconitase and ATP-citrate lyase were significantly higher in ‘HAL’. Nevertheless, the mitochondrial aconitase activity, the gene transcript levels of proton pumps, including vacuolar H+-ATPase, vacuolar H+-PPase, and the juice sac-predominant p-type proton pump gene (CsPH8) were significantly lower in ‘HAL’. These results implied that ‘HAL’ has higher abilities for citrate biosynthesis and utilization, but lower ability for the citrate uptake into vacuole compared with ‘AL’. Combined with the metabolites-analyzing results, a model was then established and suggested that the reduction in proton pump activity is the key factor for the low citrate accumulation and the comprehensive metabolite alterations as well in ‘HAL’. PMID:27385485

Estimating conformation content of a protein using citrate-stabilized Au nanoparticles

NASA Astrophysics Data System (ADS)

Deka, Jashmini; Paul, Anumita; Chattopadhyay, Arun

2010-08-01

Herein we report the use of the optical properties of citrate-stabilized gold nanoparticles (Au NPs) for estimation of native or denatured conformation content in a mixture of a protein in solution. The UV-vis extinction spectrum of citrate-stabilized Au NPs is known to broaden differently in the presence of native and denatured states of α-amylase, bovine serum albumin (BSA) or amyloglucosidase (AMG). On the other hand, herein we show that when a mixture of native and denatured protein was present in the medium, the broadening of the spectrum differed for different fractional content of the conformations. Also, the total area under the extinction spectrum varied linearly with the change in the mole fraction content of a state and for a constant total protein concentration. Transmission electron microscopy (TEM) measurements revealed different levels of agglomeration for different fractional contents of the native or denatured state of a protein. In addition, time-dependent denaturation of a protein could be followed using the present method. The rate constants calculated for denaturation indicated a possible fast change in conformation of a protein before complete thermal denaturation. The observations have been explained based on the changes in extinction coefficient (thereby oscillator strength) upon interaction of citrate-stabilized NPs with proteins being in different states and levels of agglomeration.Herein we report the use of the optical properties of citrate-stabilized gold nanoparticles (Au NPs) for estimation of native or denatured conformation content in a mixture of a protein in solution. The UV-vis extinction spectrum of citrate-stabilized Au NPs is known to broaden differently in the presence of native and denatured states of α-amylase, bovine serum albumin (BSA) or amyloglucosidase (AMG). On the other hand, herein we show that when a mixture of native and denatured protein was present in the medium, the broadening of the spectrum differed for

[Application of improved regional citrate anticoagulation in continuous hemofiltration in children].

PubMed

Bai, K; Liu, C J; Fu, Y Q; Xu, F

2017-05-04

Objective: To investigate the application of regional citrate anticoagulation with calcium hemofiltration basic solution in continuous hemofiltration in children. Method: The clinical data of 18 patients with citrate anticoagulation in continuous hemofiltration in children, excluding the hepatic failure and septic shock cases, were analyzed retrospectively, from September 2015 to August 2016 in Intensive Care Unit of the Children's Hospital of Chongqing Medical University.The commercial calcium hemofiltration basic solution was used as displacement liquid . The blood gas analysis, electrolyte, four coagulation tests during the treatment and the corresponding relations of quantity of blood flow(QB), quantity of citrate flow(QCi), quantity of sodium bicarbonate flow(QSB), quantity of calcium flow(QCa), quantity of filtered solution flow (Qf) were monitored. Meanwhile, the blood gas analysis, electrolyte, four coagulation tests, useful life of filter, bleeding and clotting events internal and external before, during and after the treatments were monitored, too. And the common complications of citrate anticoagulation, such as hypocalcaemia, metabolic alkalosis, citrate accumulation and hypernatremia were observed. Result: Continuous hemofiltration was applied in 18 patients for 734.5 hours, and the average useful life of filter was (25±11)h.There was no obvious clotting event. There were 168 groups of datum of the blood gas analysis, electrolyte, four coagulation tests during the treatment and the relationships of QB, QCi, QSB, QCa, Qf had been collected. The relationships of the initial parameter settings of QB, QCi, QSB, QCa and Qf were concluded as QCi=1.8×QB, QCa=0.12×QB, QSB=0.01×Qf . There were 150 times(89.3%)of extracorporeal ionized calcium(iCa(E)(2+)) and 162 times(96.4%) of intracorporal ionized calcium(iCa(I)(2+)) reached the anticoagulation target. Although all the comparisons of Na(+) ((136.2±4.1) vs .(138.2±2.4) vs .(138.5±3.9)mmol/L), iCa(2+) ((1

Removal of lead and phosphate ions from aqueous solutions by organo-smectite.

PubMed

Bajda, Tomasz; Szala, Barbara; Solecka, Urszula

2015-01-01

Smectite has been modified using hexadecyltrimethyl ammonium bromide in an amount of double cationic exchange capacity. This alteration makes it possible to use organo-smectite as a sorbent to remove anionic forms. The experiment consisted of the interchangeable sorption of phosphate(V) and lead(II) by organo-smectite. Research was carried out with varying pH (2-5) and various concentrations (0.1-5 mmol/L). Organo-smectite with previously adsorbed lead ions removed more phosphate than the untreated organo-smectite. Experimental data show that lead is more likely to absorb on the organo-smectite than on the organo-smectite with previously adsorbed phosphate ions. It follows that the most effective use of the organo-smectite is through the sorption of first - Pb cations and then PO4 anions. With an increasing concentration of Pb(II) or P(V), the sorption efficiency increases. The maximum sorption efficiency of lead and phosphate ions is observed at pH 5. This enables the removal of harmful lead and phosphorus compounds from waste water and immobilizes them on the sorbent's surface. The alternating reactions of lead and phosphorus ions result in the crystallization of brompyromorphite Pb5(PO4)3Br.

Dynamics of meso and thermo citrate synthases with implicit solvation

NASA Astrophysics Data System (ADS)

Cordeiro, J. M. M.

The dynamics of hydration of meso and thermo citrate synthases has been investigated using the EEF1 methodology implemented with the CHARMM program. The native enzymes are composed of two identical subunits, each divided into a small and large domain. The dynamics behavior of both enzymes at 30°C and 60°C has been compared. The results of simulations show that during the hydration process, each subunit follows a different pathway of hydration, in spite of the identical sequence. The hydrated structures were compared with the crystalline structure, and the root mean square deviation (RMSD) of each residue along the trajectory was calculated. The regions with larger and smaller mobility were identified. In particular, helices belonging to the small domain are more mobile than those of the large domain. In contrast, the residues that constitute the active site show a much lower displacement compared with the crystalline structure. Hydration free energy calculations point out that Thermoplasma acidophilum citrate synthase (TCS) is more stable than chicken citrate synthase (CCS), at high temperatures. Such result has been ascribed to the higher number of superficial charges in the thermophilic homologue, which stabilizes the enzyme, while the mesophilic homologue denatures. These results are in accord with the experimental found that TCS keeps activity at temperatures farther apart from the catalysis regular temperature than the CCS.

78 FR 34338 - Citric Acid and Certain Citrate Salts From Canada: Preliminary Results of Antidumping Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-07

... DEPARTMENT OF COMMERCE International Trade Administration [A-122-853] Citric Acid and Certain... on citric acid and certain citrate salts (citric acid) from Canada. The period of review (POR) is May... INFORMATION: Scope of the Order The merchandise covered by this order is citric acid and certain citrate salts...

Comparison of Elaeagnus angustifolia Extract and Sildenafil Citrate on Female Orgasmic Disorders: A Randomized Clinical Trial.

PubMed

Akbarzadeh, Marzieh; Zeinalzadeh, Sanaz; Zolghadri, Jaleh; Mohagheghzadeh, Abdolali; Faridi, Pouya; Sayadi, Mehrab

2014-10-01

Orgasmic disorder can create a feeling of deprivation and failure and provide mental problems, incompatibility and marital discord. This study aimed to compare the effects of Elaeagnus angustifolia flower extract and sildenafil citrate on female orgasmic disorder in women in 2013. In this randomized clinical trial, 125 women between 18-40 years old who suffered from orgasmic disorder were divided into three E. angustifolia, sildenafil citrate and control groups. The data were gathered using Female Sexual Function Index and through measurement of TSH and prolactin. The first intervention group had to consume 4.5 gr E. angustifolia extract in two divided doses for 35 days and the second one had to use 50 mg sildenafil citrate tablets for 4 weeks one hour before their sexual relationship. However, the control group had to consume the placebo. The data were analyzed using paired t-test, one-way ANOVA, and Bonferroni posthoc test and p<0.05 was considered significant. The frequency of orgasmic disorder before the intervention was 41.5%, 40.5%, and 57.1% in E. angustifolia, sildenafil citrate, and control groups, respectively (p=0.23). However, these measures were respectively 29.3%, 16.7%, and 50% after the intervention (p=0.004). A significant difference between the two groups regarding sexual satisfaction after the intervention (p=0.003) compared to the beginning of the study (p=0.356). Besides, the highest reduction of changes after the intervention (58.82%) was observed in the sildenafil citrate group. Both E. angustifolia extract and sildenafil citrate were effective in reduction of the frequency of orgasmic disorder in women.

Diethyl citrate and sodium citrate reduce the cytotoxic effects of nanosized hydroxyapatite crystals on mouse vascular smooth muscle cells

PubMed Central

Zhang, Chong-Yu; Sun, Xin-Yuan; Ouyang, Jian-Ming; Gui, Bao-Song

2017-01-01

Objective This study aimed to investigate the damage mechanism of nanosized hydroxyapatite (nano-HAp) on mouse aortic smooth muscle cells (MOVASs) and the injury-inhibiting effects of diethyl citrate (Et2Cit) and sodium citrate (Na3Cit) to develop new drugs that can simultaneously induce anticoagulation and inhibit vascular calcification. Methods The change in cell viability was evaluated using a cell proliferation assay kit, and the amount of lactate dehydrogenase (LDH) released was measured using an LDH kit. Intracellular reactive oxygen species (ROS) and mitochondrial damage were detected by DCFH-DA staining and JC-1 staining. Cell apoptosis and necrosis were detected by Annexin V staining. Intracellular calcium concentration and lysosomal integrity were measured using Fluo-4/AM and acridine orange, respectively. Results Nano-HAp decreased cell viability and damaged the cell membrane, resulting in the release of a large amount of LDH. Nano-HAp entered the cells and damaged the mitochondria, and then induced cell apoptosis by producing a large amount of ROS. In addition, nano-HAp increased the intracellular Ca2+ concentration, leading to lysosomal rupture and cell necrosis. On addition of the anticoagulant Et2Cit or Na3Cit, cell viability and mitochondrial membrane potential increased, whereas the amount of LDH released, ROS, and apoptosis rate decreased. Et2 Cit and Na3Cit could also chelate with Ca+ to inhibit the intracellular Ca2+ elevations induced by nano-HAp, prevent lysosomal rupture, and reduce cell necrosis. High concentrations of Et2Cit and Na3Cit exhibited strong inhibitory effects. The inhibitory capacity of Na3Cit was stronger than that of Et2Cit at similar concentrations. Conclusion Both Et2Cit and Na3Cit significantly reduced the cytotoxicity of nano-HAp on MOVASs and inhibited the apoptosis and necrosis induced by nano-HAp crystals. The chelating function of citrate resulted in both anticoagulation and binding to HAp. Et2Cit and Na3Cit may play a

Direct and indirect effects of RNA interference against pyridoxal kinase and pyridoxine 5'-phosphate oxidase genes in Bombyx mori.

PubMed

Huang, ShuoHao; Yao, LiLi; Zhang, JianYun; Huang, LongQuan

2016-08-01

Vitamin B6 comprises six interconvertible pyridine compounds (vitamers), among which pyridoxal 5'-phosphate is a coenzyme involved in a high diversity of biochemical reactions. Humans and animals obtain B6 vitamers from diet, and synthesize pyridoxal 5'-phosphate by pyridoxal kinase and pyridoxine 5'-phosphate oxidase. Currently, little is known on how pyridoxal 5'-phosphate biosynthesis is regulated, and pyridoxal 5'-phosphate is supplied to meet their requirement in terms of cofactor. Bombyx mori is a large silk-secreting insect, in which protein metabolism is most active, and the vitamin B6 demand is high. In this study, we successfully down-regulated the gene expression of pyridoxal kinase and pyridoxine 5'-phosphate oxidase by body cavity injection of synthesized double-stranded small interfering RNA to 5th instar larvae of Bombyx mori, and analyzed the gene transcription levels of pyridoxal 5'-phosphate dependent enzymes, phosphoserine aminotransferase and glutamic-oxaloacetic transaminase. Results show that the gene expression of pyridoxal kinase and pyridoxine 5'-phosphate oxidase has a greater impact on the gene transcription of enzymes using pyridoxal 5'-phosphate as a cofactor in Bombyx mori. Our study suggests that pyridoxal 5'-phosphate biosynthesis and dynamic balance may be regulated by genetic networks. Copyright © 2016 Elsevier B.V. All rights reserved.

Transport of citrate-coated silver nanoparticles in unsaturated sand

NASA Astrophysics Data System (ADS)

Kumahor, Samuel; Hron, Pavel; Metreveli, George; Schaumann, Gabriele; Vogel, Hans-Jörg

2015-04-01

Chemical factors and physical constraints lead to coupled effects during particle transport in unsaturated porous media. Unlike for saturated transport, studies on unsaturated transport as typical for soil are currently scarce. We investigated the mobility of citrate-coated Ag NPs in unsaturated sand (grain diameter: 0.1-0.3 mm). For three flux rates and a given pore-water ionic strength (1 mM KNO3), the citrate-coated Ag NPs were less mobile at pH = 5 compared to pH = 9. The classic Derjaguin-Landau-Verwey-Overbeek (DLVO) theory suggests unfavorable deposition conditions at both, the air-water interface and solid-water interface. Breakthrough curves measured under quasi-steady state unsaturated flow showed retardation of the citrate-coated Ag NPs compared to inert solute (KBr). After flushing with nanoparticle-free 1 mM KNO3 solution (pH-adjusted), retention was much lower in deeper depths compared to the surface where the particles entered the flow field. The results show a non-linear dependence of nanoparticle (NP) mobility on flux rate and water content. Especially the observed retardation similar to equilibrium sorption is in contrast to observations under saturated flow conditions. A convection-dispersion and reaction model that combines a reversible equilibrium process and a non-equilibrium interaction process reproduced the measured breakthrough curves reasonably well. From comparison between saturated and unsaturated experiments we conclude that the air-water interface is responsible for the reversible equilibrium process while the water-solid interface accounts for irreversible soption.

Diffuse abdominal uptake of Ga-67 citrate in a patient with hypoproteinemia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, E.K.; Gobuty, A.; Guiterrez, C.

1983-06-01

A 3-wk-old male, with abdominal distention and severe hypoproteinemia from poor nutrition, underwent a study that showed a persistent diffuse abdominal uptake of Ga-67 citrate, indicating pyogenic or tuberculous peritonitis. However, there were no corresponding clinical or laboratory findings. After a 1-wk course of hyperalimentation with albumin, furosemide, and protein, repeat radiographs showed reduction in bowel gas. It is suggested that hypoproteinemia should be considered as a possibility in the differential diagnosis when there is diffuse abdominal uptake of Ga-67 citrate, with careful clinical correlation. Possible mechanism of Ga-67 uptake in the peritoneal cavity is suggested.

Signal transfer through three compartments: transcription initiation of the Escherichia coli ferric citrate transport system from the cell surface.

PubMed

Härle, C; Kim, I; Angerer, A; Braun, V

1995-04-03

Transport of ferric citrate into cells of Escherichia coli K-12 involves two energy-coupled transport systems, one across the outer membrane and one across the cytoplasmic membrane. Previously, we have shown that ferric citrate does not have to enter the cytoplasm of E. coli K-12 to induce transcription of the fec ferric citrate transport genes. Here we demonstrate that ferric citrate uptake into the periplasmic space between the outer and the cytoplasmic membranes is not required for fec gene induction. Rather, FecA and the TonB, ExbB and ExbD proteins are involved in induction of the fec transport genes independent of their role in ferric citrate transport across the outer membrane. The uptake of ferric citrate into the periplasmic space of fecA and tonB mutants via diffusion through the porin channels did not induce transcription of fec transport genes. Point mutants in FecA displayed the constitutive expression of fec transport genes in the absence of ferric citrate but still required TonB, with the exception of one FecA mutant which showed a TonB-independent induction. The phenotype of the FecA mutants suggests a signal transduction mechanism across three compartments: the outer membrane, the periplasmic space and the cytoplasmic membrane. The signal is triggered upon the interaction of ferric citrate with FecA protein. It is postulated that FecA, TonB, ExbB and ExbD transfer the signal across the outer membrane, while the regulatory protein FecR transmits the signal across the cytoplasmic membrane to FecI in the cytoplasm. FecI serves as a sigma factor which facilitates binding of the RNA polymerase to the fec transport gene promoter upstream of fecA.(ABSTRACT TRUNCATED AT 250 WORDS)

Ranitidine bismuth citrate and ranitidine do not affect gastric emptying of a radio-labelled liquid meal.

PubMed Central

Parikh, R; Sweetland, J; Forster, E R; Bedding, A W; Farr, S J; Smith, J T

1994-01-01

Ranitidine bismuth citrate, a new chemical entity which is a salt complex of ranitidine and bismuth citrate, is being developed for the treatment of relapse of benign gastric and duodenal ulcer and eradication of Helicobacter pylori. The aim of the present study was to establish whether ranitidine bismuth citrate (800 mg) or ranitidine hydrochloride (300 mg) have any effect on gastric emptying of a liquid meal using gamma scintigraphy. On three separate occasions, each of twelve subjects received a single oral tablet of 800 mg ranitidine bismuth citrate, 300 mg ranitidine hydrochloride or placebo in random order. Thirty minutes after dosing each subject was given 375 ml of 99mTc-DTPA (diethylene triaminepentaacetic acid) labelled Clinifeed-ISO. The primary endpoint was the time to 50% gastric emptying (t50%). The proportion of the meal remaining was summarised by weighted mean proportion of the meal remaining in the stomach over 0-60 min and 0-180 min, separately. No differences were observed for t50%, weighted mean 0-60 min, and weighted mean 0-180 min between any two treatments. In man, we have detected no significant effect of single oral doses of ranitidine bismuth citrate 800 mg or ranitidine hydrochloride 300 mg on the rate of gastric emptying of a liquid meal when compared with placebo. PMID:7888296

Forsterite Carbonation in Wet Supercritical CO2 and Sodium Citrate

NASA Astrophysics Data System (ADS)

Qiu, L.; Schaef, T.; Wang, Z.; Miller, Q.; McGrail, P.

2013-12-01

Lin Qiu1*, Herbert T. Schaef2, Zhengrong Wang1, Quin R.S. Miller3, BP McGrail2 1. Yale University, New Haven, CT, USA 2. Pacific Northwest National Laboratory, Richland, WA, USA 3. University of Wyoming, Laramie, WY, USA Geologic reservoirs for managing carbon emissions (mostly CO2) have expanded over the last 5 years to include unconventional formations including basalts and fractured shales. Recently, ~1000 metric tons of CO2 was injected into the Columbia River Basalt (CRB) in Eastern Washington as part of the Wallula Pilot Project, Big Sky Regional Carbon Partnership. Based on reservoir conditions, the injected CO2 is present as a supercritical fluid that dissolves into the formation water over time, and reacts with basalt components to form carbonate minerals. In this paper, we discuss mineral transformation reactions occurring when the forsterite (Mg2SiO4) is exposed to wet scCO2 in equilibrium with pure water and sodium citrate solutions. Forsterite was selected as it is an important olivine group mineral present in igneous and mafic rocks. Citrate was selected as it has been shown to enhance mineral dissolution and organic ligands are possible degradation products of the microbial communities present in the formational waters of the CRB. For the supercritical phase, transformation reactions were examined by in situ high pressure x-ray diffraction (HXRD) in the presence of supercritical carbon dioxide (scCO2) in contact with water and sodium citrate solutions at conditions relevant to carbon sequestration. Experimental results show close-to-complete dissolution of forsterite in contact with scCO2 equilibrated with pure water for 90 hours (90 bar and 50°C). Under these conditions, thin films of water coated the mineral surface, providing a mechanism for silicate dissolution and transport of cations necessary for carbonate formation. The primary crystalline component initially detected with in situ HXRD was the hydrated magnesium carbonate, nesquehonite [Mg

Enclomiphene citrate stimulates testosterone production while preventing oligospermia: a randomized phase II clinical trial comparing topical testosterone.

PubMed

Wiehle, Ronald D; Fontenot, Gregory K; Wike, Jenny; Hsu, Kuang; Nydell, Jennifer; Lipshultz, Larry

2014-09-01

To determine the effect of enclomiphene citrate in men with secondary hypogonadism. Phase II clinical trial. Community dwelling men making visits to physician offices. Men with secondary hypogonadism. Oral administration of enclomiphene citrate or 1% topical T gel. Luteinizing hormone, FSH, T, and semen analysis. Treatment with enclomiphene citrate resulted in increased morning serum T, E2, and LH levels similar to those obtained with a topical T gel in men with secondary hypogonadism. Follicle-stimulating hormone and LH were increased with enclomiphene, and sperm counts were conserved. Enclomiphene citrate reverses the two hallmarks of secondary hypogonadism, namely, low serum total T and low or inappropriately normal LH while preserving sperm production. NCT01270841 (ClinicalTrials.gov Identifier NCT01270841). Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Enhancing the aluminium tolerance of barley by expressing the citrate transporter genes SbMATE and FRD3

PubMed Central

Zhou, Gaofeng; Ryan, Peter R.

2014-01-01

Malate and citrate efflux from root apices is a mechanism of Al3+ tolerance in many plant species. Citrate efflux is facilitated by members of the MATE (multidrug and toxic compound exudation) family localized to the plasma membrane of root cells. Barley (Hordeum vulgare) is among the most Al3+-sensitive cereal species but the small genotypic variation in tolerance that is present is correlated with citrate efflux via a MATE transporter named HvAACT1. This study used a biotechnological approach to increase the Al3+ tolerance of barley by transforming it with two MATE genes that encode citrate transporters: SbMATE is the major Al3+-tolerance gene from sorghum whereas FRD3 is involved with Fe nutrition in Arabidopsis. Independent transgenic and null T3 lines were generated for both transgenes. Lines expressing SbMATE showed Al3+-activated citrate efflux from root apices and greater tolerance to Al3+ toxicity than nulls in hydroponic and short-term soil trials. Transgenic lines expressing FRD3 exhibited similar phenotypes except citrate release from roots occurred constitutively. The Al3+ tolerance of these lines was compared with previously generated transgenic barley lines overexpressing the endogenous HvAACT1 gene and the TaALMT1 gene from wheat. Barley lines expressing TaALMT1 showed significantly greater Al3+ tolerance than all lines expressing MATE genes. This study highlights the relative efficacy of different organic anion transport proteins for increasing the Al3+ tolerance of an important crop species. PMID:24692647

Low Temperature Induced Changes in Citrate Metabolism in Ponkan (Citrus reticulata Blanco cv. Ponkan) Fruit during Maturation

PubMed Central

Lin, Qiong; Qian, Jing; Zhao, Chenning; Wang, Dengliang; Liu, Chunrong; Wang, Zhidong; Sun, Chongde; Chen, Kunsong

2016-01-01

Citrate is the most important organic acid in citrus fruit, and its concentration in fruit cells is regulated mainly by the balance between synthesis and degradation. Ponkan (Citrus reticulate Blanco cv. Ponkan) is one of the major citrus cultivars grew in China, and the fruit are picked before fully mature to avoid bad weather. Greenhouse production is widely used to prolong the maturation period and improve the quality of Ponkan fruit by maintaining adequate temperature and providing protection from adverse weather. In this research, Ponkan fruit cultivated in either a greenhouse or open field were used to investigate differences in the expression of genes related to citrate metabolism during maturation in the two environments. The citrate contents were higher in open field fruit, and were mainly correlated with expressions of CitPEPCs, CitCSs, CitAco3 and CitGAD4, which were significantly increased. In addition, the impacts of low temperature (LT) and water stress (WS) on citrate metabolism in Ponkan were investigated during fruit maturation. The citrate contents in LT fruit were significantly increased, by between 1.4–1.9 fold, compared to the control; it showed no significant difference in fruit with water stress treatment compared to the control fruit. Furthermore, the expressions of CitPEPCs, CitCSs, CitAco3 and CitGAD4 were significantly increased in response to LT treatment, but showed no significant difference in WS compared to the control fruit. Thus, it can be concluded that low temperature may be the main factor influencing citrate metabolism during maturation in Ponkan fruit. PMID:27249065

On the nature of citrate-derived surface species on Ag nanoparticles: Insights from X-ray photoelectron spectroscopy

NASA Astrophysics Data System (ADS)

Mikhlin, Yuri L.; Vorobyev, Sergey A.; Saikova, Svetlana V.; Vishnyakova, Elena A.; Romanchenko, Alexander S.; Zharkov, Sergey M.; Larichev, Yurii V.

2018-01-01

Citrate is an important stabilizing, reducing, and complexing reagent in the wet chemical synthesis of nanoparticles of silver and other metals, however, the exact nature of adsorbates, and its mechanism of action are still uncertain. Here, we applied X-ray photoelectron spectroscopy, soft X-ray absorption near-edge spectroscopy, and other techniques in order to determine the surface composition and to specify the citrate-related species at Ag nanoparticles immobilized from the dense hydrosol prepared using room-temperature reduction of aqueous Ag+ ions with ferrous ions and citrate as stabilizer (Carey Lea method). It was found that, contrary to the common view, the species adsorbed on the Ag nanoparticles are, in large part, products of citrate decomposition comprising an alcohol group and one or two carboxylate bound to the surface Ag, and minor unbound carboxylate group; these may also be mixtures of citrate with lower molecular weight anions. No ketone groups were specified, and very minor surface Ag(I) and Fe (mainly, ferric oxyhydroxides) species were detected. Moreover, the adsorbates were different at AgNPs having various size and shape. The relation between the capping and the particle growth, colloidal stability of the high-concentration sol and properties of AgNPs is briefly considered.

Bioavailable dietary phosphate, a mediator of cardiovascular disease, may be decreased with plant-based diets, phosphate binders, niacin, and avoidance of phosphate additives.

PubMed

McCarty, Mark F; DiNicolantonio, James J

2014-01-01

Increased fasting serum phosphate within the normal physiological range has been linked to increased cardiovascular risk in prospective epidemiology; increased production of fibroblast growth factor 23, and direct vascular effects of phosphate, may mediate this risk. Although dietary phosphate intake does not clearly influence fasting serum phosphate in individuals with normal renal function, increased phosphate intake can provoke a rise in fibroblast growth factor 23, and in diurnal phosphate levels, and hence may adversely influence vascular health. Dietary phosphate absorption can be moderated by emphasizing plant-based dietary choices (which provide phosphate in less bioavailable forms); avoidance of processed foods containing inorganic phosphate food additives; and by ingestion of phosphate-binder drugs, magnesium supplements, or niacin, which precipitate phosphate or suppress its gastrointestinal absorption. The propensity of dietary phosphate to promote vascular calcification may be opposed by optimal intakes of magnesium, vitamin K, and vitamin D; the latter should also counter the tendency of phosphate to elevate parathyroid hormone. Copyright © 2014 Elsevier Inc. All rights reserved.

New protocol of clomiphene citrate treatment in women with hypothalamic amenorrhea.

PubMed

Borges, Lavinia Estrela; Morgante, Giuseppe; Musacchio, Maria Concetta; Petraglia, Felice; De Leo, Vincenzo

2007-06-01

To determine if a new protocol of administration of clomiphene citrate (CC) is effective in menstrual cycle recovery in women with hypothalamic secondary amenorrhea. This was an open-label study. Patients comprised a group of eight women with secondary amenorrhea. Interventions. An oral preparation containing CC (50 mg/day) was administered for 5 days followed by a double dose (100 mg/day) for another 5 days, initiated on day 3 after estrogen/progestogen-induced withdrawal bleeding. If ovulation and vaginal bleeding occurred, treatment continued in the two next months with 100 mg/day from day 3 to day 7 day of the cycle. Cycle control was evaluated at each visit, when patients recorded bleeding patterns and tablet intake. Data on the intensity and duration of bleeding were collected. Six patients responded to the first cycle of CC administration, resuming normal menstrual cycles. The other two patients failed to menstruate after the first 10 days of treatment with CC and repeated the same protocol. After the second administration, these two women also had normal menstrual bleeding. The present data show that this new protocol of CC treatment may be useful to restore normal menstrual cycles in young women with hypothalamic amenorrhea.

Methodology of citrate-based biomaterial development and application

NASA Astrophysics Data System (ADS)

Tran, M. Richard

Biomaterials play central roles in modern strategies of regenerative medicine and tissue engineering. Attempts to find tissue-engineered solutions to cure various injuries or diseases have led to an enormous increase in the number of polymeric biomaterials over the past decade. The breadth of new materials arises from the multiplicity of anatomical locations, cell types, and mode of application, which all place application-specific requirements on the biomaterial. Unfortunately, many of the currently available biodegradable polymers are limited in their versatility to meet the wide range of requirements for tissue engineering. Therefore, a methodology of biomaterial development, which is able to address a broad spectrum of requirements, would be beneficial to the biomaterial field. This work presents a methodology of citrate-based biomaterial design and application to meet the multifaceted needs of tissue engineering. We hypothesize that (1) citric acid, a non-toxic metabolic product of the body (Krebs Cycle), can be exploited as a universal multifunctional monomer and reacted with various diols to produce a new class of soft biodegradable elastomers with the flexibility to tune the material properties of the resulting material to meet a wide range of requirements; (2) the newly developed citrate-based polymers can be used as platform biomaterials for the design of novel tissue engineering scaffolding; and (3) microengineering approaches in the form thin scaffold sheets, microchannels, and a new porogen design can be used to generate complex cell-cell and cell-microenvironment interactions to mimic tissue complexity and architecture. To test these hypotheses, we first developed a methodology of citrate-based biomaterial development through the synthesis and characterization of a family of in situ crosslinkable and urethane-doped elastomers, which are synthesized using simple, cost-effective strategies and offer a variety methods to tailor the material properties to

FecB, a periplasmic ferric-citrate transporter from E. coli, can bind different forms of ferric-citrate as well as a wide variety of metal-free and metal-loaded tricarboxylic acids.

PubMed

Banerjee, Sambuddha; Paul, Subrata; Nguyen, Leonard T; Chu, Byron C H; Vogel, Hans J

2016-01-01

The Escherichia coli Fec system, consisting of an outer membrane receptor (FecA), a periplasmic substrate binding protein (FecB) and an inner membrane permease-ATPase type transporter (FecC/D), plays an important role in the uptake and transport of Fe(3+)-citrate. Although several FecB sequences from various organisms have been reported, there are no biophysical or structural data available for this protein to date. In this work, using isothermal titration calorimetry (ITC), we report for the first time the ability of FecB to bind different species of Fe(3+)-citrate as well as other citrate complexes with trivalent (Ga(3+), Al(3+), Sc(3+) and In(3+)) and a representative divalent metal ion (Mg(2+)) with low μM affinity. Interestingly, ITC experiments with various iron-free di- and tricarboxylic acids show that FecB can bind tricarboxylates with μM affinity but not biologically relevant dicarboxylates. The ability of FecB to bind with metal-free citrate is also observed in (1)H,(15)N HSQC-NMR titration experiments reported here at two different pH values. Further, differential scanning calorimetry (DSC) experiments indicate that the ligand-bound form of FecB has greater thermal stability than ligand-free FecB under all pH and ligand conditions tested, which is consistent with the idea of domain closure subsequent to ligand binding for this type of periplasmic binding proteins.

NMR spectroscopic study of organic phosphate esters coprecipitated with calcite

NASA Astrophysics Data System (ADS)

Phillips, Brian L.; Zhang, Zelong; Kubista, Laura; Frisia, Silvia; Borsato, Andrea

2016-06-01

Organic phosphorus incorporated in calcite during laboratory precipitation experiments and in natural cave deposits was investigated by solid-state NMR spectroscopy. For calcite precipitated in the presence of organic phosphoesters of varying size and functionality, solid-state 31P{1H} CP/MAS NMR shows that the phosphoesters were incorporated intact into the solid. Systematic changes in the 31P NMR chemical shift of the phosphate group were observed between the solid phosphoester and that incorporated in the solid precipitate, yielding 31P NMR chemical shifts of the coprecipitates in the range of +1.8 to -2.2 ppm. These chemical shifts are distinct from that of similarly prepared calcite coprecipitated with inorganic phosphate, 3.5 ppm. Only minor changes were noted in the phosphoester 31P chemical shift anisotropy (CSA) which suggests no significant change in the local structure of the phosphate group, which is dominated by C-O-P bonding. Close spatial proximity of the organic phosphate group to calcite structural components was revealed by 31P/13C rotational echo double resonance (REDOR) experiments for coprecipitates prepared with 13C-labeled carbonate. All coprecipitates showed significant 31P dephasing effects upon 13C-irradiation, signaling atomic-scale proximity to carbonate carbon. The dephasing rate for smaller organophosphate molecules is similar to that observed for inorganic phosphate, whereas much slower dephasing was observed for larger molecules having long and/or bulky side-chains. This result suggests that small organic molecules can be tightly enclosed within the calcite structure, whereas significant structural disruption required to accommodate the larger organic molecules leads to longer phosphate-carbonate distances. Comparison of 31P NMR spectroscopic data from the synthetic coprecipitates with those from calcite moonmilk speleothems indicates that phosphorus occurs mainly as inorganic orthophosphate in the natural deposits, although small

Influence of centrifuge brake on residual platelet count and routine coagulation tests in citrated plasma.

PubMed

Daves, Massimo; Giacomuzzi, Katia; Tagnin, Enrico; Jani, Erika; Adcock Funk, Dorothy M; Favaloro, Emmanuel J; Lippi, Giuseppe

2014-04-01

Sample centrifugation is an essential step in the coagulation laboratory, as clotting tests are typically performed on citrated platelet (PLT) poor plasma (PPP). Nevertheless, no clear indication has been provided as to whether centrifugation of specimens should be performed with the centrifuge brake set to on or off. Fifty consecutive sodium citrate anticoagulated samples were collected and divided into two aliquots. The former was centrifuged as for Clinical Laboratory Standards Institute (CLSI) guidelines with the centrifuge brake set to on, whereas the latter was centrifuged again as for CLSI guidelines, but with the brake set to off. In the PPP of all samples, a PLT count was performed, followed by the analysis of activated partial thromboplastin time (APTT), prothrombin time (PT) and fibrinogen (FBG). The PLT count after samples centrifugation was substantially reduced, either with centrifuge brake set to on or off (5 ± 1 versus 3 ± 1 × 10/l; P = 0.009). The frequency of samples exceeding a PLT count less than 10 × 10/l was nearly double in samples centrifuged with the brake on than in those with the brake off (14 versus 8%; P < 0.01). Although no significant difference was found for APTT values, PT was slightly prolonged using the centrifuge brake set to on (mean bias 0.2 s; P < 0.001). FBG values were also significantly higher using the centrifuge brake set to on (mean bias 0.29 g/l; P < 0.001). The results of this study indicate that sample centrifugation for routine coagulation testing should be preferably performed with the centrifuge brake set to off for providing a better quality specimen.

Effect of combined locally delivered growth factors and systemic sildenafil citrate on microrecanalization in biodegradable conduit for vas deferens reconstruction.

PubMed

Rosevear, Henry M; Krishnamachari, Yogita; Ariza, Carlos A; Mallapragada, Surya K; Salem, Aliasger K; Griffith, Thomas S; De Young, Barry R; Wald, Moshe

2012-04-01

To investigate the effect of the combination of locally delivered growth factors and oral sildenafil citrate on cross-conduit microrecanalization. A total of 42 rats were divided into 7 groups. Of the 42 rats, 6 underwent bilateral vasectomy and bilateral end-to-end vasovasostomy and 12 underwent bilateral vasectomy. Of the latter 12, 6 received sildenafil citrate orally (10 mg/kg/d) for 24 weeks and 6 received placebo. A total of 24 rats underwent bilateral vasectomy and bilateral reconstruction with implantation of a 5-mm biodegradable conduit that bridged the 2 vasal ends. Of the 24 rats with conduits, 12 also had 250 pg of transforming growth factor-β and 12.5 pg of platelet-derived growth factor-β sustained release nanoparticles placed in immediate proximity to the conduit. The remaining 12 rats with conduits (6 without growth factors and 6 with growth factors) also received sildenafil citrate orally (10 mg/kg/d) for 24 weeks; the others received placebo. The reconstructed segments were harvested for histologic examination at 24 weeks. Five of 6 primary vasovasostomy and no vasectomy-only rats sired litters. Significantly more microcanals per conduit were observed in rats receiving sildenafil citrate: without growth factors, 3.9 vs. 0 canals/conduit (P < 0.001); with growth factors, 5.5 vs. 0.25 canals/conduit (P < 0.001). The rats receiving sildenafil citrate with growth factors showed a trend toward more microcanals per conduit than the rats receiving sildenafil citrate without growth factors (5.5 vs 3.9; P = .10). Rats receiving growth factors but no sildenafil citrate did not produce more canals than the rats receiving neither growth factor nor sildenafil citrate (0.25 vs 0; P = NS). Orally administered sildenafil citrate enhances formation of microcanalization after postvasectomy reconstruction using a biodegradable conduit in a rat model. Locally delivered growth factors appear to increase the number of microcanals. Copyright © 2012 Elsevier Inc. All

Tight ceramic UF membrane as RO pre-treatment: the role of electrostatic interactions on phosphate rejection.

PubMed

Shang, Ran; Verliefde, Arne R D; Hu, Jingyi; Zeng, Zheyi; Lu, Jie; Kemperman, Antoine J B; Deng, Huiping; Nijmeijer, Kitty; Heijman, Sebastiaan G J; Rietveld, Luuk C

2014-01-01

Phosphate limitation has been reported as an effective approach to inhibit biofouling in reverse osmosis (RO) systems for water purification. The rejection of dissolved phosphate by negatively charged TiO2 tight ultrafiltration (UF) membranes (1 kDa and 3 kDa) was observed. These membranes can potentially be adopted as an effective process for RO pre-treatment in order to constrain biofouling by phosphate limitation. This paper focuses on electrostatic interactions during tight UF filtration. Despite the larger pore size, the 3 kDa ceramic membrane exhibited greater phosphate rejection than the 1 kDa membrane, because the 3 kDa membrane has a greater negative surface charge and thus greater electrostatic repulsion against phosphate. The increase of pH from 6 to 8.5 led to a substantial increase in phosphate rejection by both membranes due to increased electrostatic repulsion. At pH 8.5, the maximum phosphate rejections achieved by the 1 kDa and 3 kDa membrane were 75% and 86%, respectively. A Debye ratio (ratio of the Debye length to the pore radius) is introduced in order to evaluate double layer overlapping in tight UF membranes. Threshold Debye ratios were determined as 2 and 1 for the 1 kDa and 3 kDa membranes, respectively. A Debye ratio below the threshold Debye ratio leads to dramatically decreased phosphate rejection by tight UF membranes. The phosphate rejection by the tight UF, in combination with chemical phosphate removal by coagulation, might accomplish phosphate-limited conditions for biological growth and thus prevent biofouling in the RO systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

21 CFR 520.623 - Diethylcarbamazine citrate, oxibendazole chewable tablets.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Diethylcarbamazine citrate, oxibendazole chewable tablets. 520.623 Section 520.623 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS...

21 CFR 520.623 - Diethylcarbamazine citrate, oxibendazole chewable tablets.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Diethylcarbamazine citrate, oxibendazole chewable tablets. 520.623 Section 520.623 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS...

21 CFR 520.623 - Diethylcarbamazine citrate, oxibendazole chewable tablets.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Diethylcarbamazine citrate, oxibendazole chewable tablets. 520.623 Section 520.623 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS...

21 CFR 520.623 - Diethylcarbamazine citrate, oxibendazole chewable tablets.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Diethylcarbamazine citrate, oxibendazole chewable tablets. 520.623 Section 520.623 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS...

A Comparative 68Ga-Citrate and 68Ga-Chloride PET/CT Imaging of Staphylococcus aureus Osteomyelitis in the Rat Tibia

PubMed Central

Lankinen, Petteri; Noponen, Tommi; Autio, Anu; Luoto, Pauliina; Löyttyniemi, Eliisa; Hakanen, Antti J.

2018-01-01

There may be some differences in the in vivo behavior of 68Ga-chloride and 68Ga-citrate leading to different accumulation profiles. This study compared 68Ga-citrate and 68Ga-chloride PET/CT imaging under standardized experimental models. Methods. Diffuse Staphylococcus aureus tibial osteomyelitis and uncomplicated bone healing rat models were used (n = 32). Two weeks after surgery, PET/CT imaging was performed on consecutive days using 68Ga-citrate or 68Ga-chloride, and tissue accumulation was confirmed by ex vivo analysis. In addition, peripheral quantitative computed tomography and conventional radiography were performed. Osteomyelitis was verified by microbiological analysis and specimens were also processed for histomorphometry. Results. In PET/CT imaging, the SUVmax of 68Ga-chloride and 68Ga-citrate in the osteomyelitic tibias (3.6 ± 1.4 and 4.7 ± 1.5, resp.) were significantly higher (P = 0.0019 and P = 0.0020, resp.) than in the uncomplicated bone healing (2.7 ± 0.44 and 2.5 ± 0.49, resp.). In osteomyelitic tibias, the SUVmax of 68Ga-citrate was significantly higher than the uptake of 68Ga-chloride (P = 0.0017). In animals with uncomplicated bone healing, no difference in the SUVmax of 68Ga-chloride or 68Ga-citrate was seen in the operated tibias. Conclusions. This study further corroborates the use of 68Ga-citrate for PET imaging of osteomyelitis. PMID:29681785

A universal small molecule, inorganic phosphate, restricts the substrate specificity of Dicer-2 in small RNA biogenesis

PubMed Central

Fukunaga, Ryuya; Zamore, Phillip D

2014-01-01

The enzyme Dicer is central to the production of small silencing RNAs such as microRNAs (miRNAs) and small interfering RNAs (siRNAs). Like other insects, Drosophila melanogaster uses different Dicers to make siRNAs and miRNAs: Dicer-1 produces miRNAs from pre-miRNAs, whereas Dicer-2 generates siRNAs from long double-stranded RNA (dsRNA). How do the 2 Dicers achieve their substrate specificity? Here, we review recent findings that inorganic phosphate restricts the substrate specificity of Dicer-2 to long dsRNA. Inorganic phosphate inhibits Dicer-2 from binding and cleaving pre-miRNAs, without affecting the processing of long dsRNA. Crystal structures of a fragment of human Dicer in complex with an RNA duplex identify a phosphate-binding pocket that recognizes both the 5′-monophosphate of a substrate RNA and inorganic phosphate. We propose that inorganic phosphate occupies the phosphate-binding pocket in the fly Dicer-2, blocking binding of pre-miRNA and restricting pre-miRNA processing to Dicer-1. Thus, a small molecule can alter the substrate specificity of a nucleic acid-processing enzyme. PMID:24787225

Sildenafil Citrate in Fetal Growth Restriction

PubMed Central

Panda, Subrat; Das, Ananya; Md Nowroz, Hossain

2014-01-01

Background Pregnancies with early onset fetal growth restriction have poor perinatal outcome. Sildenafil citrate (PDE -5 inhibitor) as a vasodilator increases utero-placental blood flow and potentiates fetal growth. Case Presentation In this study, a case was examined and Sildenafil was administered for her. It was found that Sildenafil improved the uterine blood flow with a favorable fetal outcome at delivery. Conclusion Sildenafil, as a vasodilator has emerged as a potential management option in the treatment of Intra Uterine Growth Retardation (IUGR) and preeclampsia by later normalization in velocimetric profile. PMID:25202677

Determination of total arsenic and arsenic(III) in phosphate fertilizers by hydride generation atomic absorption spectrometry after ultrasound-assisted extraction based on a control acid media.

PubMed

Rezende, Helen Cristine; Coelho, Nivia Maria Melo

2014-01-01

An ultrasound-assisted extraction procedure was developed for determination of inorganic arsenic (As) in phosphate fertilizer by hydride generation atomic absorption spectrometry. The variables that affect the hydride generation step were optimized, including the reducer, acid, sample flow rate, and concentrations of the acid and reducer. The determination of As(lll) was performed through the simple control of solution pH with a 0.5 M citric acid-sodium citrate buffer solution at pH 4.5, and total As was determined after a pre-reduction reaction with 1.0% (w/v) thiourea. Ultrasound-assisted acid extraction was performed, and the parameters sonication time and acid and Triton X-114 concentrations were optimized using a 23 factorial design and central composite design. LODs for As(lll) and total As were 0.029 and 0.022 microg/L, respectively. The accuracy of the method was confirmed with certified reference materials. The method was successfully applied in the determination of inorganic As in phosphate fertilizer samples.

Fast degradable citrate-based bone scaffold promotes spinal fusion.

PubMed

Tang, Jiajun; Guo, Jinshan; Li, Zhen; Yang, Cheng; Xie, Denghui; Chen, Jian; Li, Shengfa; Li, Shaolin; Kim, Gloria B; Bai, Xiaochun; Zhang, Zhongmin; Yang, Jian

2015-07-21

It is well known that high rates of fusion failure and pseudoarthrosis development (5~35%) are concomitant in spinal fusion surgery, which was ascribed to the shortage of suitable materials for bone regeneration. Citrate was recently recognized to play an indispensable role in enhancing osteconductivity and osteoinductivity, and promoting bone formation. To address the material challenges in spinal fusion surgery, we have synthesized mechanically robust and fast degrading citrate-based polymers by incorporating N-methyldiethanolamine (MDEA) into clickable poly(1, 8-octanediol citrates) (POC-click), referred to as POC-M-click. The obtained POC-M-click were fabricated into POC-M-click-HA matchstick scaffolds by compositing with hydroxyapatite (HA) for interbody spinal fusion in a rabbit model. Spinal fusion was analyzed by radiography, manual palpation, biomechanical testing, and histological evaluation. At 4 and 8 weeks post surgery, POC-M-click-HA scaffolds presented optimal degradation rates that facilitated faster new bone formation and higher spinal fusion rates (11.2±3.7, 80±4.5 at week 4 and 8, respectively) than the poly(L-lactic acid)-HA (PLLA-HA) control group (9.3±2.4 and 71.1±4.4) (p<0.05). The POC-M-click-HA scaffold-fused vertebrates possessed a maximum load and stiffness of 880.8±14.5 N and 843.2±22.4 N/mm, respectively, which were also much higher than those of the PLLA-HA group (maximum: 712.0±37.5 N, stiffness: 622.5±28.4 N/mm, p<0.05). Overall, the results suggest that POC-M-click-HA scaffolds could potentially serve as promising bone grafts for spinal fusion applications.

Women taking the "blue pill" (sildenafil citrate): such a big deal?

PubMed

Lo Monte, Giuseppe; Graziano, Angela; Piva, Isabella; Marci, Roberto

2014-01-01

For years, phosphodiesterase type 5 inhibitors have been used for the treatment of erectile dysfunctions. Due to the similarities between male and female sexual response, several studies have assessed the effects of sildenafil citrate (Viagra(®)) in women affected by female sexual arousal disorder. The results are still conflicting and the drug is not devoid of adverse effects. Furthermore, female sexual arousal disorder is a heterogeneous condition whose underlying causes are difficult to diagnose and appropriate treatment requires a thorough sexual, psychological, and medical history along with specialist consultations. The clinician should pursue a global approach to the patient with sexual difficulties, while non-hormonal treatment such as phosphodiesterase type 5 inhibitors (ie, sildenafil citrate) should be kept as the last option.

Enhancing the aluminium tolerance of barley by expressing the citrate transporter genes SbMATE and FRD3.

PubMed

Zhou, Gaofeng; Pereira, Jorge F; Delhaize, Emmanuel; Zhou, Meixue; Magalhaes, Jurandir V; Ryan, Peter R

2014-06-01

Malate and citrate efflux from root apices is a mechanism of Al(3+) tolerance in many plant species. Citrate efflux is facilitated by members of the MATE (multidrug and toxic compound exudation) family localized to the plasma membrane of root cells. Barley (Hordeum vulgare) is among the most Al(3+)-sensitive cereal species but the small genotypic variation in tolerance that is present is correlated with citrate efflux via a MATE transporter named HvAACT1. This study used a biotechnological approach to increase the Al(3+) tolerance of barley by transforming it with two MATE genes that encode citrate transporters: SbMATE is the major Al(3+)-tolerance gene from sorghum whereas FRD3 is involved with Fe nutrition in Arabidopsis. Independent transgenic and null T3 lines were generated for both transgenes. Lines expressing SbMATE showed Al(3+)-activated citrate efflux from root apices and greater tolerance to Al(3+) toxicity than nulls in hydroponic and short-term soil trials. Transgenic lines expressing FRD3 exhibited similar phenotypes except citrate release from roots occurred constitutively. The Al(3+) tolerance of these lines was compared with previously generated transgenic barley lines overexpressing the endogenous HvAACT1 gene and the TaALMT1 gene from wheat. Barley lines expressing TaALMT1 showed significantly greater Al(3+) tolerance than all lines expressing MATE genes. This study highlights the relative efficacy of different organic anion transport proteins for increasing the Al(3+) tolerance of an important crop species. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

21 CFR 520.622 - Diethylcarbamazine citrate oral dosage forms.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Diethylcarbamazine citrate oral dosage forms. 520.622 Section 520.622 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622...

21 CFR 520.622 - Diethylcarbamazine citrate oral dosage forms.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Diethylcarbamazine citrate oral dosage forms. 520.622 Section 520.622 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622...

21 CFR 520.622 - Diethylcarbamazine citrate oral dosage forms.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Diethylcarbamazine citrate oral dosage forms. 520.622 Section 520.622 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622...

21 CFR 520.622 - Diethylcarbamazine citrate oral dosage forms.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Diethylcarbamazine citrate oral dosage forms. 520.622 Section 520.622 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622...

21 CFR 520.622 - Diethylcarbamazine citrate oral dosage forms.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Diethylcarbamazine citrate oral dosage forms. 520.622 Section 520.622 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622...

Stability of the Stevia-Derived Sweetener Rebaudioside A in Solution as Affected by Ultraviolet Light Exposure.

PubMed

Zhang, Jiewen; Bell, Leonard N

2017-04-01

Rebaudioside A is a natural noncaloric high-potency sweetener extracted from the leaves of Stevia rebaudiana. With rebaudioside A use increasing in foods, understanding the factors affecting its stability is necessary. This project evaluated the degradation rate constants of rebaudioside A in water, 0.1 M phosphate buffer, and 0.1 M citrate buffer at pH 3 and 7 as a function of ultraviolet (UV) light intensity (365 nm, 0 μW/cm 2 for dark conditions, 27 μW/cm 2 for low intensity, and 190 μW/cm 2 for high intensity) at 32.5 °C. Rebaudioside A stability was adversely affected by light exposure. The pseudo-1st-order degradation rate constants increased significantly (P < 0.05) with increasing light intensity in all solutions. Under dark conditions, rebaudioside A in phosphate buffers was more susceptible to breakdown than in water and citrate buffers at both pH levels. However, exposure to UV light resulted in rebaudioside A degradation occurring approximately 10 times faster in citrate than in phosphate buffers at both pH levels. The sensitivity of rebaudioside A to UV light was greater in citrate buffers than in water or phosphate buffers. The use of light-protective packaging for beverages containing rebaudioside A will improve its stability. © 2017 Institute of Food Technologists®.

Effects of sildenafil citrate (viagra) on cardiac repolarization and on autonomic control in subjects with chronic heart failure.

PubMed

Piccirillo, Gianfranco; Nocco, Marialuce; Lionetti, Marco; Moisè, Antonio; Naso, Camilla; Marigliano, Vincenzo; Cacciafesta, Mauro

2002-04-01

Cases of sudden death associated with sildenafil citrate use have been reported in men with coronary artery disease. The aim of this study was to investigate the drug's effect on cardiac repolarization and sinus autonomic and vascular control in men with mild chronic heart failure (CHF; New York Heart Association classification II). Changes in these variables could predispose patients to malignant ventricular arrhythmias. We measured QT dispersion, the QT-RR slope, and the index of QT variability (QTVI) and analyzed spectral power of RR and systolic blood pressure variability in 10 men with dilated cardiomyopathy and in 10 control subjects after administration of a single 50-mg oral dose of sildenafil citrate or placebo at rest (not followed with any attempt at intercourse). In both groups, oral sildenafil citrate decreased the systolic blood pressure (P <.05) and increased the heart rate (P <.05). In subjects with CHF, it also increased the QT-RR (P <.001) and QTVI (from -0.45 +/- 0.07 to -0.27 +/- 0.07; P <.001), but in controls, it increased the QTVI (from -1.20 +/- 0.08 to -0.78 +/-.014; P <.001). In these subjects and controls, oral sildenafil citrate induced a significant reduction in high frequency, expressed in absolute power (subjects with CHF: from 4.04 +/- 0.14 to 3.43 +/- 0.16 natural logarithm ms2; P <.001; controls: from 5.61 +/- 0.44 to 4.98 +/- 0.32 natural logarithm ms2; P <.05) and in normalized units (P <.05). In subjects with CHF but not in controls, it also significantly increased the low frequency to high frequency ratio (from 1.3 +/- 0.12 to 1.89 +/- 0.16; P <.001) and low frequency expressed in normalized units (P <.05). Sildenafil citrate caused no significant changes in the QT interval or dispersion. These findings indicate that, in men with heart failure, sildenafil citrate reduces vagal modulation and increases sympathetic modulation, probably through its reflex vasodilatory action. The autonomic system changes induced with sildenafil

Effectiveness of Sodium Picosulfate/Magnesium Citrate (PICO) for Colonoscopy Preparation

PubMed Central

Suh, Wu Seok; Jeong, Jin Sik; Kim, Dong Sik; Kim, Sang Woo; Kwak, Dong Min; Hwang, Jong Seong; Kim, Hyun Jin; Park, Man Woo; Shim, Min Chul; Koo, Ja-Il; Kim, Jae Hwang; Shon, Dae Ho

2014-01-01

Purpose Bowel preparation with sodium phosphate was recently prohibited by the U.S. Food and Drug Administration. Polyethylene glycol (PEG) is safe and effective; however, it is difficult to drink. To identify an easy bowel preparation method for colonoscopy, we evaluated three different bowel preparation regimens regarding their efficacy and patient satisfaction. Methods In this randomized, comparative study, 892 patients who visited a secondary referral hospital for a colonoscopy between November 2012 and February 2013 were enrolled. Three regimens were evaluated: three packets of sodium picosulfate/magnesium citrate (PICO, group A), two packets of PICO with 1 L of PEG (PICO + PEG 1 L, group B), and two packets of PICO with 2 L of PEG (PICO + PEG 2 L, group C). A questionnaire survey regarding the patients' preference for the bowel preparation regimen and satisfaction was conducted before the colonoscopies. The quality of bowel cleansing was scored by the colonoscopists who used the Aronchick scoring scale and the Ottawa scale. Results The patients' satisfaction rate regarding the regimens were 72% in group A, 64% in group B, and 45.9% in group C. Nausea and abdominal bloating caused by the regimens were more frequent in group C than in group A or group B (P < 0.01). Group C showed the lowest preference rate compared to the other groups (P < 0.01). Group C showed better right colon cleansing efficacy than group A or group B. Conclusion Group A exhibited a better result than group B or group C in patient satisfaction and preference. In the cleansing quality, no difference was noted between groups A and C. PMID:25360429

Comparison of the effects of letrozole and clomiphene citrate for ovulation induction in infertile women with polycystic ovary syndrome.

PubMed

Nahid, L; Sirous, K

2012-06-01

Ovulation dysfunction is one of the most common causes of reproductive failure in infertile couples. The prevalence of this disorder in infertile women is about 30 to 40%. Polycystic ovary syndrome is a common disease that is closely related to ovulation dysfunction and 7% of women of childbearing age are afflicted with it. Ovulation induction is a way to treat infertility in PCOS which is possible through medication or surgery. This study was conducted to compare the effects of Letrozole and Clomiphene citrate for ovulation induction in women with PCOS. This intervention is a clinical trial study carried out on 100 infertile women with polycystic ovary syndrome who were referred to gynecologist's office and Oslian hospital. The subjects were randomly divided in to two groups including 50 patients who received letrozole and Clomiphene Citrate. Abdominal ultrasound was performed on the day 14 of the menstrual cycle to monitor the number and size of developed follicles and endometrial thickness.%age of ovulation was compared between the two groups receiving medication with χ2 test and t-test was used to compare the average number and size of follicles and endometrial thickness. Twenty-three cases (46%) in group receiving clomiphene citrate had thin endometrium and thin endometrium was observed in 1 case (2%) of group receiving letrozole. Among 50 subjects who received clomiphene citrate, 10 people (20%) reported blurred vision, 9 patients (18%) headache, 6 patients (12%) nausea and 2 patients (4%) reported vomiting and one (2%) twin pregnancies was observed, but no complications were reported in group receiving letrozole. Mean age, parity, and the duration of infertility were similar in all patients. Ovulation rate was 88%; similar in both groups. The average number of follicles in the group receiving clomiphene citrate was 58/1±32/2 and in the group receiving letrezole it was 50/0±30/1. Average follicle size in both groups was almost similar. Endometrial

Structural and transport properties of double perovskite Dy{sub 2}NiMnO{sub 6}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chanda, Sadhan, E-mail: sadhan.physics@gmail.com; Saha, Sujoy; Dutta, Alo

2015-02-15

Highlights: • Sol–gel citrate method is used to prepare the double perovskite Dy{sub 2}NiMnO{sub 6}. • Structure and dielectric relaxation of the sample are studied for nano and bulk phases. • The relaxation mechanism of the sample is modeled by Cole–Cole equation. • With increasing sintering temperature conductivity increases. • Electronic structures and magnetic properties have been studied by DFT calculations. - Abstract: The double perovskite oxide Dy{sub 2}NiMnO{sub 6} (DNMO) is synthesized in nano and bulk phase by the sol–gel citrate method. The Rietveld refinement of X-ray diffraction pattern of the sample at room temperature shows the monoclinic P2{submore » 1}/n phase. Dielectric relaxation of the sample is investigated in the impedance and electric modulus formalisms in the frequency range from 50 Hz to 1 MHz and in the temperature range from 253 to 415 K. The Cole–Cole model is used to explain the relaxation mechanism in DNMO. The frequency-dependent maxima in the imaginary part of impedance are found to obey an Arrhenius law with activation energy of 0.346 and 0.344 eV for nano and bulk DNMO, respectively. A significant increase in conductivity of bulk DNMO has been observed than that of the nanoceramic. Electronic structures and magnetic properties of DNMO have been studied by performing first principles calculation based on density functional theory.« less

Use of intraurethral alprostadil in patients not responding to sildenafil citrate.

PubMed

Jaffe, Jamison S; Antell, Mara R; Greenstein, Marc; Ginsberg, Phillip C; Mydlo, Jack H; Harkaway, Richard C

2004-05-01

To determine whether intraurethral alprostadil would be an effective alternative for men with erectile dysfunction who did not respond adequately to sildenafil citrate but desired minimally invasive treatment. A total of 44 male patients aged 41 to 74 years with erectile dysfunction refractory to treatment with sildenafil citrate were enrolled in this study. Of the 44 patients, 10 had undergone prior radical retropubic prostatectomy. The patients were evaluated for subjective improvement in an office setting and completed the Sexual Health Inventory for Men questionnaire as an objective assessment of improved erectile ability. Success was defined as subjective improvement in erectile function, as well as an improved Sexual Health Inventory for Men score. Of the 44 men, 13 (29.5%) responded successfully to intraurethral alprostadil, with a follow-up ranging from 2 to 15 months. The remaining 31 men had no response (n = 28, 90%), refused escalating doses (n = 2, 7%), or were lost to follow-up (n = 1, 3%). In the subgroup of 10 men with prior radical retropubic prostatectomy, 5 (50%) reported success with intraurethral alprostadil (500 microg in 2 patients and 1000 microg in 3 patients). Although sildenafil citrate remains the most common initial therapy in men with erectile dysfunction, intraurethral alprostadil may be a reasonable treatment option for sildenafil nonresponders. This may be especially true in men having undergone prior radical retropubic prostatectomy.

Rapid Evolution of Citrate Utilization by Escherichia coli by Direct Selection Requires citT and dctA

PubMed Central

Van Hofwegen, Dustin J.; Hovde, Carolyn J.

2016-01-01

ABSTRACT The isolation of aerobic citrate-utilizing Escherichia coli (Cit+) in long-term evolution experiments (LTEE) has been termed a rare, innovative, presumptive speciation event. We hypothesized that direct selection would rapidly yield the same class of E. coli Cit+ mutants and follow the same genetic trajectory: potentiation, actualization, and refinement. This hypothesis was tested with wild-type E. coli strain B and with K-12 and three K-12 derivatives: an E. coli ΔrpoS::kan mutant (impaired for stationary-phase survival), an E. coli ΔcitT::kan mutant (deleted for the anaerobic citrate/succinate antiporter), and an E. coli ΔdctA::kan mutant (deleted for the aerobic succinate transporter). E. coli underwent adaptation to aerobic citrate metabolism that was readily and repeatedly achieved using minimal medium supplemented with citrate (M9C), M9C with 0.005% glycerol, or M9C with 0.0025% glucose. Forty-six independent E. coli Cit+ mutants were isolated from all E. coli derivatives except the E. coli ΔcitT::kan mutant. Potentiation/actualization mutations occurred within as few as 12 generations, and refinement mutations occurred within 100 generations. Citrate utilization was confirmed using Simmons, Christensen, and LeMaster Richards citrate media and quantified by mass spectrometry. E. coli Cit+ mutants grew in clumps and in long incompletely divided chains, a phenotype that was reversible in rich media. Genomic DNA sequencing of four E. coli Cit+ mutants revealed the required sequence of mutational events leading to a refined Cit+ mutant. These events showed amplified citT and dctA loci followed by DNA rearrangements consistent with promoter capture events for citT. These mutations were equivalent to the amplification and promoter capture CitT-activating mutations identified in the LTEE. IMPORTANCE E. coli cannot use citrate aerobically. Long-term evolution experiments (LTEE) performed by Blount et al. (Z. D. Blount, J. E. Barrick, C. J. Davidson, and

Microbial solubilization of phosphate

DOEpatents

Rogers, R.D.; Wolfram, J.H.

1993-10-26

A process is provided for solubilizing phosphate from phosphate containing ore by treatment with microorganisms which comprises forming an aqueous mixture of phosphate ore, microorganisms operable for solubilizing phosphate from the phosphate ore and maintaining the aqueous mixture for a period of time and under conditions operable to effect the microbial solubilization process. An aqueous solution containing soluble phosphorus can be separated from the reacted mixture by precipitation, solvent extraction, selective membrane, exchange resin or gravity methods to recover phosphate from the aqueous solution. 6 figures.

Microbial solubilization of phosphate

DOEpatents

Rogers, Robert D.; Wolfram, James H.

1993-01-01

A process is provided for solubilizing phosphate from phosphate containing ore by treatment with microorganisms which comprises forming an aqueous mixture of phosphate ore, microorganisms operable for solubilizing phosphate from the phosphate ore and maintaining the aqueous mixture for a period of time and under conditions operable to effect the microbial solubilization process. An aqueous solution containing soluble phosphorous can be separated from the reacted mixture by precipitation, solvent extraction, selective membrane, exchange resin or gravity methods to recover phosphate from the aqueous solution.

Improving quality of colonoscopy by adding simethicone to sodium phosphate bowel preparation

PubMed Central

Tongprasert, Sasinee; Sobhonslidsuk, Abhasnee; Rattanasiri, Sasivimol

2009-01-01

AIM: To evaluate the effectiveness of simethicone in enhancing visibility and efficacy during colonoscopy. METHODS: A prospective, double-blind, randomized, placebo-controlled study was conducted. One hundred and twenty-four patients were allocated to receive 2 doses of sodium phosphate plus 240 mg of tablet simethicone or placebo as bowel preparation. Visibility was blindly assessed for the amount of air bubbles and adequacy of colon preparation. Total colonoscopic time, side effects of the medication, endoscopist and patient satisfaction were also compared. RESULTS: Sodium phosphate plus simethicone, compared to sodium phosphate plus placebo, improved visibility by diminishing air bubbles (100.00% vs 42.37%, P < 0.0001) but simethicone failed to demonstrate improvement in adequacy of colon preparation (90.16% vs 81.36%, P = 0.17). Endoscopist and patient satisfaction were increased significantly in the simethicone group. However, there was no difference in the total duration of colonoscopy and side effects of the medication. CONCLUSION: The addition of simethicone is of benefit for colonoscopic bowel preparation by diminishing air bubbles, which results in enhanced visibility. Endoscopist and patient satisfaction is also increased. PMID:19554657

Improving quality of colonoscopy by adding simethicone to sodium phosphate bowel preparation.

PubMed

Tongprasert, Sasinee; Sobhonslidsuk, Abhasnee; Rattanasiri, Sasivimol

2009-06-28

To evaluate the effectiveness of simethicone in enhancing visibility and efficacy during colonoscopy. A prospective, double-blind, randomized, placebo-controlled study was conducted. One hundred and twenty-four patients were allocated to receive 2 doses of sodium phosphate plus 240 mg of tablet simethicone or placebo as bowel preparation. Visibility was blindly assessed for the amount of air bubbles and adequacy of colon preparation. Total colonoscopic time, side effects of the medication, endoscopist and patient satisfaction were also compared. Sodium phosphate plus simethicone, compared to sodium phosphate plus placebo, improved visibility by diminishing air bubbles (100.00% vs 42.37%, P < 0.0001) but simethicone failed to demonstrate improvement in adequacy of colon preparation (90.16% vs 81.36%, P = 0.17). Endoscopist and patient satisfaction were increased significantly in the simethicone group. However, there was no difference in the total duration of colonoscopy and side effects of the medication. The addition of simethicone is of benefit for colonoscopic bowel preparation by diminishing air bubbles, which results in enhanced visibility. Endoscopist and patient satisfaction is also increased.

A study of the effects of citrate-coated silver nanoparticles on RAW 264.7 cells using a toolbox of cytotoxic endpoints

NASA Astrophysics Data System (ADS)

Bastos, V.; Duarte, I. F.; Santos, C.; Oliveira, H.

2017-05-01

Citrate-coated silver nanoparticles (citrate-AgNPs) are among the most commonly used nanomaterials, widely present in industrial and biomedical products. In this study, the cytotoxicity of 30-nm citrate-AgNPs on the macrophage cell line RAW 264.7 was evaluated, using a battery of cytotoxicity endpoints (viability, oxidative stress, and cytostaticity/clastogenicity), at 24 and 48 h of exposure. Citrate-AgNPs decreased cell proliferation and viability only at 75 μg/mL, suggesting a low sensitivity of RAW cells to lower doses of these AgNPs. After 24 h of exposure, ROS content decreased in cells exposed to 60 μg/mL AgNPs (IC20 value), corroborating the high tolerance of these cells to citrate-AgNPs. However, these cells suffered an impairment of the cell cycle, shown by an increase at the sub-G1 phase. This increase of the sub-G1 population was correlated with an increase of DNA fragmentation, suggesting an increase of apoptosis. Thus, our data are important to understand the effects of low concentrations (IC20) of citrate-AgNPs on in vitro vital macrophage functions.

Extremely High Phosphate Sorption Capacity in Cu-Pb-Zn Mine Tailings.

PubMed

Huang, Longbin; Li, Xiaofang; Nguyen, Tuan A H

2015-01-01

Elevated inorganic phosphate (Pi) concentrations in pore water of amended tailings under direct revegetation may cause toxicity in some native woody species but not native forbs or herb species, all of which are key constituents in target native plant communities for phytostabilizing base metal mine tailings. As a result, Pi sorption capacity has been quantified by a conventional batch procedure in three types of base metal mine tailings sampled from two copper (Cu)-lead (Pb)-zinc (Zn) mines, as the basis for Pi-fertiliser addition. It was found that the Pi-sorption capacity in the tailings and local soil was extremely high, far higher than highly weathered agricultural soils in literature, but similar to those of volcanic ash soils. The Langmuir P-sorption maximum was up to 7.72, 4.12, 4.02 and 3.62 mg P g-1 tailings, in the fresh tailings of mixed Cu-Pb-Zn streams (MIMTD7), the weathered tailings of mixed Cu-Pb-Zn streams (MIMTD5), EHM-TD (fresh Cu-stream, high magnetite content) and local soil (weathered shale and schist), respectively. Physicochemical factors highly correlated with the high Pi-sorption in the tailings were fine particle distribution, oxalate and dithionite-citrate-bicarbonate extractable Fe (FeO and Fed), oxalate-extractable Al and Mn, and the levels of soluble Cd and Zn, and total S and Fe. Large amounts of amorphous Fe oxides and oxyhydroxides may have been formed from the oxidation of pyritic materials and redox cycles of Fe-minerals (such as pyrite (FeS2), ankerite (Ca(Fe Mg)(CO3)2 and siderite (FeCO3), as indicated by the extractable FeO values. The likely formation of sparingly soluble Zn-phosphate in the Pb-Zn tailings containing high levels of Zn (from sphalerite ((Zn,Fe)S, ZnS, (Zn,Cd)S)) may substantially lower soluble Zn levels in the tailings through high rates of Pi-fertiliser addition. As a result, the possibility of P-toxicity in native plant species caused by the addition of soluble phosphate fertilizers would be minimal.

In situ molecular NMR picture of bioavailable calcium stabilized as amorphous CaCO3 biomineral in crayfish gastroliths

PubMed Central

Akiva-Tal, Anat; Kababya, Shifi; Balazs, Yael S.; Glazer, Lilah; Berman, Amir; Sagi, Amir; Schmidt, Asher

2011-01-01

Bioavailable calcium is maintained by some crustaceans, in particular freshwater crayfish, by stabilizing amorphous calcium carbonate (ACC) within reservoir organs—gastroliths, readily providing the Ca2+ needed to build a new exoskeleton. Despite the key scientific and biomedical importance of the in situ molecular-level picture of biogenic ACC and its stabilization in a bioavailable form, its description has eluded efforts to date. Herein, using multinuclear NMR, we accomplish in situ molecular-level characterization of ACC within intact gastroliths of the crayfish Cherax quadricarinatus. In addition to the known CaCO3, chitin scaffold and inorganic phosphate (Pi), we identify within the gastrolith two primary metabolites, citrate and phosphoenolpyruvate (PEP) and quantify their abundance by applying solution NMR techniques to the gastrolith “soluble matrix.” The long-standing question on the physico-chemical state of ACC stabilizing, P-bearing moieties within the gastrolith is answered directly by the application of solid state rotational-echo double-resonance (REDOR) and transferred-echo double-resonance (TEDOR) NMR to the intact gastroliths: Pi and PEP are found molecularly dispersed throughout the ACC as a solid solution. Citrate carboxylates are found < 5 Å from a phosphate (intermolecular C⋯P distance), an interaction that must be mediated by Ca2+. The high abundance and extensive interactions of these molecules with the ACC matrix identify them as the central constituents stabilizing the bioavailable form of calcium. This study further emphasizes that it is imperative to characterize the intact biogenic CaCO3. Solid state NMR spectroscopy is shown to be a robust and accessible means of determining composition, internal structure, and molecular functionality in situ. PMID:21873244

21 CFR 520.622c - Diethylcarbamazine citrate chewable tablets.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Diethylcarbamazine citrate chewable tablets. 520.622c Section 520.622c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.622c...