Pharmacokinetics of ceftiofur sodium and ceftiofur crystalline free acid in neonatal foals

Calcium ions (Ca) participate in many signal transduction processes, and for that reason it is important to determine where these ions are located within the living cell, and when and to what extent they change their local concentration. Of the different Ca-specific indicators, the fluorescent dyes, developed by Grynkiewicz et al. (1), have proved most efficacious, however, their use on plants has met with several problems (2). First, the dyes as acetoxy-methyl esters are often cleaved by extracellular esterases in the plant cell wall, and thus they do not enter the cell. Second, if the dye crosses the plasma membrane it may continue into non-cytoplasmic membrane compartments. Third, even if cleaved by esterases in the cytoplasm, or introduced as the free acid into the cytoplasmic compartment, the dyes often become quickly sequestered into vacuoles and organelles, or extruded from the cell. Finally, the free acid form of the dye readily complexes with proteins reducing its ability to detect free calcium. All these problems lead to an erroneous measurement of calcium (2).

Download Full-text

Pharmacokinetics of ceftiofur crystalline free acid in pigs vaccinated against, challenged with, or vaccinated against and challenged with PRRSv

10.31274/etd-180810-4018 ◽

2015 ◽

Author(s):

Joel Wayne Sparks

Keyword(s):

Free Acid

Download Full-text

The protonation of the ethylenediphosphinetetraacetate anion and the crystal structure of the bis (hydrogen bromide) of ethylenediphosphinetetraacetic acid

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19813063 ◽

1981 ◽

Vol 46 (12) ◽

pp. 3063-3073 ◽

Cited By ~ 5

Author(s):

Jana Podlahová ◽

Bohumil Kratochvíl ◽

Vratislav Langer ◽

Josef Šilha ◽

Jaroslav Podlaha

Keyword(s):

Crystal Structure ◽

Hydrogen Bonds ◽

Structure Determination ◽

Free Acid ◽

Hydrogen Bromide ◽

Carboxyl Groups ◽

Spectroscopic Methods ◽

X Ray ◽

Partial Formation

The equilibria and mechanism of addition of protons to the ethylenediphosphinetetraacetate anion (L4-) were studied in solution by the UV, IR, 1H and 31P NMR spectroscopic methods. A total of six protons can be bonded to the anion. They are added stepwise, first with partial formation of zwitterions containing P-H bonds, which then dissociate with formation of the free acid, H4L, where all four protons are bonded in carboxyl groups. The formation of zwitterions is strongly dependent on the concentration. In the final stage, the acid bonds two additional protons to form the bis-phosphonium cation, H6L2+. A number of isostructural salts containing this cation, H4L.2 HX (X = Cl, Br, I), have been prepared. The X-ray crystal structure determination of the bromide confirmed the expected arrangement. The bromide crystals are monoclinic, a = 578.2, b = 1 425.0, c = 1 046.7 pm, β = 103.07° with a space group of P21/c, Z = 2. The final R factor was 0.059 based on 1 109 observed reflections. The structure consists of H6L2+ cations containing protons bonded to phosphorus atoms (P-H distance 134 pm) and of bromide anions, located in gaps which are also sufficiently large for I- anions in the isostructural iodide. The interbonding of phosphonium cations proceeds through hydrogen bonds, C-OH...O=C, in which the O...O distance is 275.3 pm.

Download Full-text

Impact of Ceftiofur Administration in Steers on the Prevalence and Antimicrobial Resistance of Campylobacter spp.

Microorganisms ◽

10.3390/microorganisms9020318 ◽

2021 ◽

Vol 9 (2) ◽

pp. 318

Author(s):

Sicun Fan ◽

Derek Foster ◽

William G. Miller ◽

Jason Osborne ◽

Sophia Kathariou

Keyword(s):

Antimicrobial Resistance ◽

Bacterial Resistance ◽

Active Drug ◽

Free Acid ◽

Structural Similarity ◽

Drug Concentrations ◽

Pre Treatment ◽

Ceftiofur Hydrochloride ◽

Campylobacter Spp

Bacterial resistance to ceftiofur raises health concerns due to ceftiofur’s extensive veterinary usage and structural similarity with the human antibiotic ceftriaxone. Ceftiofur crystalline-free acid (CCFA) and ceftiofur hydrochloride (CHCL) are ceftiofur types used therapeutically in cattle, but their potential impacts on Campylobacter prevalence and antimicrobial resistance remain unclear. In this study two groups of steers were each treated with CCFA or CHCL. In vivo active drug concentrations were measured and fecal samples were analyzed for Campylobacter for up to 42 days post-treatment. Following administration, the colonic concentration of ceftiofur initially increased then dropped to pre-treatment levels by day 8. The estimated prevalence of Campylobacter spp. was significantly (p = 0.0009) higher during the first week after CCFA treatment than after CHCL treatment (81.3% vs. 45.2%). Campylobacter jejuni predominated overall, with other Campylobacter spp. mainly identified in the first week after CCFA treatment. No treatment impacts were noted on ceftiofur minimum inhibitory concentration (MIC) for C. jejuni (10–20 μg/mL). More C. jejuni genotypes were detected in CCFA-treated than CHCL-treated steers. These findings suggest that ceftiofur did not significantly impact Campylobacter prevalence or ceftiofur MIC. However, CHCL may be preferable due to the lower likelihood of temporary increases in Campylobacter prevalence.

Download Full-text

Preparation and structural analysis of (±)-threo-ritalinic acid

Acta Crystallographica Section C Crystal Structure Communications ◽

10.1107/s010827011302595x ◽

2013 ◽

Vol 69 (11) ◽

pp. 1225-1228 ◽

Cited By ~ 2

Author(s):

Sara Wyss ◽

Irmgard A. Werner ◽

W. Bernd Schweizer ◽

Simon M. Ametamey ◽

Selena Milicevic Sephton

Keyword(s):

Methyl Ester ◽

Free Acid ◽

Nmr Analysis ◽

Intermolecular Hydrogen Bonds ◽

X Ray ◽

X Ray Crystallography ◽

Ph Values ◽

Ritalinic Acid ◽

Methyl Phenidate ◽

Hydrolysis Of

Hydrolysis of the methyl ester (±)-threo-methyl phenidate afforded the free acid in 40% yield,viz.(±)-threo-ritalinic acid, C13H17NO2. Hydrolysis and subsequent crystallization were accomplished at pH values between 5 and 7 to yield colourless prisms which were analysed by X-ray crystallography. Crystals of (±)-threo-ritalinic acid belong to theP21/nspace group and form intermolecular hydrogen bonds. An antiperiplanar disposition of the H atoms of the (HOOC—)CH—CHpygroup (py is pyridine) was found in both the solid (diffraction analysis) and solution state (NMR analysis). It was also determined that (±)-threo-ritalinic acid conforms to the minimization of negativegauche+–gauche−interactions.

Download Full-text

Liquid chromatography-tandem mass spectrometry method for simultaneous quantification of azoxystrobin and its metabolites, azoxystrobin free acid and 2-hydroxybenzonitrile, in greenhouse-grown lettuce

Food Additives & Contaminants Part A ◽

10.1080/19440049.2017.1382729 ◽

2017 ◽

Vol 34 (12) ◽

pp. 2173-2180 ◽

Cited By ~ 2

Author(s):

Maheswor Gautam ◽

Inge S. Fomsgaard

Keyword(s):

Mass Spectrometry ◽

Liquid Chromatography ◽

Tandem Mass Spectrometry ◽

Free Acid ◽

Tandem Mass ◽

Spectrometry Method ◽

Mass Spectrometry Method ◽

Simultaneous Quantification ◽

Chromatography Tandem Mass Spectrometry ◽

Liquid Chromatography Tandem Mass

Download Full-text

Effects of acidosis on resting cytosolic and mitochondrial Ca2+ in mammalian myocardium.

The Journal of General Physiology ◽

10.1085/jgp.102.3.575 ◽

1993 ◽

Vol 102 (3) ◽

pp. 575-597 ◽

Cited By ~ 26

Author(s):

G Gambassi ◽

R G Hansford ◽

S J Sollott ◽

B A Hogue ◽

E G Lakatta ◽

...

Keyword(s):

Lactic Acid ◽

Ventricular Myocytes ◽

Free Acid ◽

Left Ventricular ◽

Ruthenium Red ◽

Acetoxymethyl Ester ◽

Cytosolic Ph ◽

Bicarbonate Buffer ◽

Adult Rat ◽

Mammalian Myocardium

Acidosis increases resting cytosolic [Ca2+], (Cai) of myocardial preparations; however, neither the Ca2+ sources for the increase in Cai nor the effect of acidosis on mitochondrial free [Ca2+], (Cam) have been characterized. In this study cytosolic pH (pHi) was monitored in adult rat left ventricular myocytes loaded with the acetoxymethyl ester (AM form) of SNARF-1. A stable decrease in the pHi of 0.52 +/- 0.05 U (n = 16) was obtained by switching from a bicarbonate buffer equilibrated with 5% CO2 to a buffer equilibrated with 20% CO2. Electrical stimulation at either 0.5 or 1.5 Hz had no effect on pHi in 5% CO2, nor did it affect the magnitude of pHi decrease in response to hypercarbic acidosis. Cai was measured in myocytes loaded with indo-1/free acid and Cam was monitored in cells loaded with indo-1/AM after quenching cytosolic indo-1 fluorescence with MnCl2. In quiescent intact myocytes bathed in 1.5 mM [Ca2+], hypercarbia increased Cai from 130 +/- 5 to 221 +/- 13 nM. However, when acidosis was effected in electrically stimulated myocytes, diastolic Cai increased more than resting Cai in quiescent myocytes, and during pacing at 1.5 Hz diastolic Cai was higher (285 +/- 17 nM) than at 0.5 Hz (245 +/- 18 nM; P < 0.05). The magnitude of Cai increase in quiescent myocytes was not affected either by sarcoplasmic reticulum (SR) Ca2+ depletion with ryanodine or by SR Ca2+ depletion and concomitant superfusion with a Ca(2+)-free buffer. In unstimulated intact myocytes hypercarbia increased Cam from 95 +/- 12 to 147 +/- 19 nM and this response was not modified either by ryanodine and a Ca(2+)-free buffer or by 50 microM ruthenium red in order to block the mitochondrial uniporter. In mitochondrial suspensions loaded either with BCECF/AM or indo-1/AM, acidosis produced by lactic acid addition decreased both intra- and extramitochondrial pH and increased Cam. Studies of mitochondrial suspensions bathed in indo-1/free acid-containing solution showed an increase in extramitochondrial Ca2+ after the addition of lactic acid. Thus, in quiescent myocytes, cytoplasmic and intramitochondrial buffers, rather than transsarcolemmal Ca2+ influx or SR Ca2+ release, are the likely Ca2+ sources for the increase in Cai and Cam, respectively; additionally, Ca2+ efflux from the mitochondria may contribute to the raise in Cai. In contrast, in response to acidosis, diastolic Cai in electrically stimulated myocytes increases more than resting Cai in quiescent cells; this suggests that during pacing, net cell Ca2+ gain contributes to enhance diastolic Cai.

Download Full-text