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Objective: To study the pharmacokinetics of difloxacin (5 mg/kg) following IV, IM, and intragastric (IG) administration to healthy horses., Animals: 6 healthy mature horses., Procedures: A crossover study design with 3 phases was used (15-day washout periods between treatments). An injectable formulation of difloxacin (5%) was administered IV and IM in single doses (5 mg/kg); for IG administration, an oral solution was prepared and administered via nasogastric tube. Blood samples were collected before and at intervals after each administration. A high-performance liquid chromatography assay with fluorescence detection was used to determine plasma difloxacin concentrations. Pharmacokinetic parameters of difloxacin were analyzed. Plasma creatine kinase activity was monitored to assess tissue damage., Results: Difloxacin plasma concentration versus time data after IV administration were best described by a 2-compartment open model. The disposition of difloxacin following IM or IG administration was best described by a 1-compartment model. Mean half-life for difloxacin administered IV, IM, and IG was 2.66, 5.72, and 10.75 hours, respectively. Clearance after IV administration was 0.28 L/kg.h. After IM administration, the absolute mean +/- SD bioavailability was 95.81 +/- 3.11% and maximum plasma concentration (Cmax) was 1.48 +/- 0.12 mg/L. After IG administration, the absolute bioavailability was 68.62 +/- 10.60% and Cmax was 0.732 +/- 0.05 mg/L. At 12 hours after IM administration, plasma creatine kinase activity had increased 7-fold, compared with the preinjection value., Conclusions and Clinical Relevance: Data suggest that difloxacin is likely to be effective for treating susceptible bacterial infections in horses.

A number of N-substituted piperazinylquinolone derivatives were synthesized and evaluated for antibacterial activity against Gram-positive and Gram-negative bacteria. Preliminary results indicated that most compounds tested in this study demonstrated comparable or better activity against Staphylococcus aureus and Staphylococcus epidermidis than their parent piperazinylquinolones as reference drugs. Among these derivatives, ciprofloxacin derivative 5a, containing N-[2-[5-(methylthio)thiophen-2-yl]-2-oxoethyl] residue, showed significant improvement of potency against staphylococci, maintaining Gram-negative coverage.

Ciprofloxacin is a broad-spectrum antibacterial drug, being used in a wide range of infections. A method to quantify the total (unbound + protein-bound) ciprofloxacin concentrations in human serum is presented based on rapid liquid-liquid extraction, followed by reversed-phase liquid chromatography and UV detection at 280 nm. The calibration range used was 2 to 10 mg/L. The mean accuracy and precision (CV%) were all within specifications: at 0.2 mg/L 81.2% (10.1%), assigned to be the lower limit of quantification (LLOQ), at 8 mg/L 103.6% (4.48%), at 14 mg/L 103.1% (3.98%). Metabolites and frequently used comedications showed minimal interference. Sample storage conditions suitable for routine determination of serum ciprofloxacin concentrations for daily therapeutic drug monitoring (gel-collection tubes and PVC tubes at 4 degrees C) and for intermittent batch-wise analyses for research purposes (PVC tubes at -18 degrees C) showed acceptable sample stability after storage for 48 hours (4 degrees C) and 6 months (-18 degrees C).

Susceptibility testing was used to evaluate potential spectrum of action for piperazinyl-cross-linked fluoroquinolone dimers against test strains of Streptococcus pneumoniae, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa, Mycobacterium tuberculosis, and vancomycin-resistant Enterococcus faecium (VRE) and to evaluate dimers against fluoroquinolone-resistant and fluoroquinolone-susceptible strains of streptococci. Individual dimers displayed equivalent or lowered MIC values compared with parent fluoroquinolone monomers against test strains of S. pneumoniae, S. pyogenes, E. coli, and VRE. Raised MIC values were observed for all dimers in comparison to monomers against test strains of P. aeruginosa and E. coli. In comparison to parent fluoroquinolones, all dimers displayed decreased percent inhibition of growth against M. tuberculosis. Structural requirements for activity of dimers and partial dimers against all organisms, including lower MICs against certain fluoroquinolone-resistant and fluoroquinolone-susceptible strains of streptococci, were consistent with requirements previously observed for dimers against fluoroquinolone-susceptible and fluoroquinolone-resistant strains of S. aureus. In contrast, the 10- to 100-fold lowering of MICs against wild-type and fluoroquinolone-resistant strains of S. aureus previously observed for individual cross-linked dimers was not observed with test strains of the various organisms used here.

A 40-year-old male diabetic presented with a 1-month history of flank pain, fever, and chills. Examination revealed pyrexia and left flank tenderness. Pus and red cells were seen on urine microscopy and Klebsiella was isolated from the urine. The patient was treated with antibiotics, but the fever persisted and he was sent for an Infecton scan that showed a large cold area in the superolateral aspect of the left kidney. Whole-body imaging failed to reveal any other abnormal site. Computed tomography (CT) demonstrated a space-occupying lesion with an air-fluid level in the upper part of the left kidney. The patient responded to several weeks of antibiotic therapy.

Unlabelled: Currently available laboratory and imaging tests have limitations diagnosing and following patients with spinal infections. We evaluated 17 Technetium-99m labeled ciprofloxacin scintigraphy studies in 11 patients who had the diagnosis of a spinal infection based on the Centers for Disease Control and Prevention criteria. Three of the 17 studies were performed in three patients within 2 months from the onset of the symptoms. All of these three studies showed increased uptake of the radiopharmaceutical in the area of the spinal infection. Fourteen studies were performed during the followup period (from 210 to 690 days after the onset of symptoms) in nine patients with spinal infections. Ten of the 14 studies performed in five patients with an active spine infection showed positive results while the patients had evidence for active spinal infection at the time of the testing. Four studies were performed during the followup period in four patients who at the time of the nuclear imaging testing had no symptoms, signs, or laboratory or other imaging evidence for active infection. All four studies showed negative results. The results of this preliminary study show that scintigraphy with 99mTc-ciprofloxacin may be useful in the diagnosis of active spinal infections., Level of Evidence: Diagnostic study, level II-1 (Testing of previously developed diagnostic criteria on consecutive patients [with universally applied reference "gold" standard]). Please see Guidelines for Authors for a complete description of levels of evidence.

A major problem associated with anti-HIV-1 treatment is rapid emergence of drug-resistant strains. Accordingly, a compelling need is to discover anti-HIV drugs against alternative viral targets in addition to HIV-1 RT, PR, IN and CCR5. One such target is the interaction between HIV Trans-activator of transcription (Tat) protein and Trans Activation Responsive region (TAR) RNA. An arginine-rich motif (ARM) of Tat recognizing both the base sequence and the active conformation of TAR RNA three-base bulge region as well as newly elucidated TAR RNA inactive conformation are important for the specific Tat-TAR interaction. According to the possible binding modes, the inhibitors have been mainly divided into two classes: (1) Compounds binding directly to TAR RNA either to the TAR RNA three-base bulge region alone or to the three-base bulge together with the lower and upper-stem/Loop region. (2) Compounds binding directly to Tat protein with high affinity, thus potently inhibiting HIV-1. They both block Tat trans-activation in the formation of the Tat/TAR complex to exert antiviral activity in primary human cells. Recent researches also focus on the drugs targeting specificity of Tat and TAR by such new assays as capillary electrophoresis and quartz crystal microbalance. Cell-based reporter systems are established for high-throughput screening of novel compounds that interfere with Tat transactivation. The identification of dominant-negative mutants also finds wide application in this field. The Tat-TAR interaction is an important target in efforts to develop anti-HIV gene therapy or potential therapeutic antiviral agents for the treatment of HIV-1 infections.

We examined inhibitory effects of ofloxacin (OFX), orbifloxacin (OBFX), ciprofloxacin (CFX), enrofloxacin (EFX) and norfloxacin (NFX) on cytochrome P-450 1A (CYP1A) activities using hepatic microsomes from four beagle dogs. Ethoxyresorufin O-de-ethylation was referred as CYP1A activities. All the fluoroquinolones inhibited the reaction in a noncompetitive manner. The determined inhibitory constants were the followings; 10.1 +/- 3.8 mM for OFX, 6.43 +/- 2.01 mM for OBFX, 0.726 +/- 0.134 mM for CFX, 4.06 +/- 1.19 mM for EFX and 4.75 +/- 1.63 mM for NFX respectively. As these values are >100-fold of plasma concentrations after a clinical single dose of the fluoroquinolones, it is suggested that the inhibitory effect on CYP1A activities is not so high to elicit drug-drug interaction with CYP1A substrates, when these fluoroquinolones are co-administered. Mechanism based inhibition was also examined in this study. Of the five fluoroquinolones examined, OFX, OBFX and CFX had this inhibition manner. As this inhibition is irreversible, inhibitory effects of the three fluoroquinolones may accumulate, when they are repeatedly administered. Therefore, OFX, OBFX and CFX may result in substantial drug-drug interaction with a CYP1A substrate even in clinical states. As EFX is metabolized to CFX in the body, it may also have the same possibility.

DYT1 is the most common inherited dystonia. Currently, there are no preventive or curative therapies for this dominantly inherited disease. DYT1 dystonia is caused by a common three-nucleotide deletion in the TOR1A gene that eliminates a glutamic acid residue from the protein torsinA. Recent studies suggest that torsinA carrying the disease-linked mutation, torsinA(DeltaE) acts through a dominant-negative effect by recruiting wild-type torsinA [torsinA(wt)] into oligomeric structures in the nuclear envelope. Therefore, suppressing torsinA(DeltaE) expression through RNA interference (RNAi) could restore the normal function of torsinA(wt), representing a potentially effective therapy regardless of the biological role of torsinA. Here, we have generated short hairpin RNAs (shRNAs) that mediate allele-specific suppression of torsinA(DeltaE) and rescue cells from its dominant-negative effect, restoring the normal distribution of torsinA(wt). In addition, delivery of this shRNA by a recombinant feline immunodeficiency virus effectively silenced torsinA(DeltaE) in a neural model of the disease. We further establish the feasibility of this viral-mediated RNAi approach by demonstrating significant suppression of endogenous torsinA in mammalian neurons. Finally, this silencing of torsinA is achieved without triggering an interferon response. These results support the potential use of viral-mediated RNAi as a therapy for DYT1 dystonia and establish the basis for preclinical testing in animal models of the disease.

A liquid chromatographic method with fluorescence detection was developed for simultaneous determination of norfloxacin, ofloxacin, ciprofloxacin, pefloxacin, lomefloxacin, danofloxacin, enrofloxacin, sarafloxacin, difloxacin, oxolinic acid, and flumequine in milk The samples were extracted with 10% trichloroacetic acid/acetonitrile (9 + 1, v/v) and cleaned by Strata-X reversed-phase solid-phase extraction cartridges. The 11 quinolones were separated on a reversed-phase C18 column (Hypersil BDS-C18) with mobile phase gradient elution and detected with fluorescence by means of a wavelength program. The recoveries for milk fortified with the 11 quinolones at 3 levels were 69-88% with acceptable relative standard deviations of <9% (intraday) and <14% (interday). The limits of detection were 23 microg/L for enrofloxacin, and 1-9 microg/L for the other 10 quinolones.

Tuberculosis continues to be a major cause of morbidity and mortality all over the world. Various 7-substituted ciprofloxacin derivatives were synthesized and evaluated for antimycobacterial activity in vitro and in vivo against Mycobacterium tuberculosis and for inhibition of the supercoiling activity of DNA gyrase from Mycobacterium smegmatis. Preliminary results indicated that most of the compounds demonstrated better in vitro antimycobacterial activity against M. tuberculosis than ciprofloxacin. Compound 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-[[N4-[1'-(5-methylisatinyl-beta-semicarbazo)]methyl]N1-piperazinyl]-3-quinoline carboxylic acid (3h) decreased the bacterial load in spleen tissue with 0.76-log10 protections and was considered to be moderately active in reducing bacterial count in spleen. The results demonstrated the potential and importance of developing new quinolone derivatives against mycobacterial infections.

This paper describes a simple methodology for evaluating the bacterial binding of ciprofloxacin labelled with technetium Tc 99m. Using this methodology, the binding of 99mTc-ciprofloxacin by live Escherichia coli was compared with the binding of 99mTc-ciprofloxacin by killed E. coli and the binding of 99mTc-pertechnetate (99mTcO4-) by live E. coli. The antimicrobial effect of 99mTc-ciprofloxacin on E. coli was evaluated. Four groups were defined: live E. coli with 99mTc-ciprofloxacin, live E. coli with 99mTcO4 , killed E. coli with 99mTc-ciprofloxacin, and killed E. coli with 99mTcO4-. After 0, 2, and 4 h of incubation of 1 x 10(8) colony-forming units of E. coli suspended in 5 mL of sterile distilled water with 1.85 MBq of 99mTc-ciprofloxacin or 99mTcO4, 1 mL from each sample was centrifuged. The radioactivity of the bacterial pellet and that of the supernatant were measured separately, and the percentage of sample radioactivity attributable to bacterial binding was calculated. Of the 99mTc-ciprofloxacin, 3.6% to 5.9% was bound to live or killed E. coli; only 0.1% to 0.2% of the 99mTcO4- was bound to live E. coli (P < 0.0001). No significant difference in 99mTc-ciprofloxacin binding was found between live and killed E. coli (P = 0.887). An antimicrobial effect on E. coli was seen with 99mTc-ciprofloxacin: colony counts were reduced after 4 h. The small amount of 99mTc-ciprofloxacin binding and the lack of difference in binding between live and killed E. coli may limit the utility of this methodology in evaluating the presence of E. coli infection.

The use of radiolabelled antibiotics is fast emerging as a promising diagnostic test for the detection of infective lesions, because of their specific binding to the bacterial component. Ciprofloxacin is a broad-spectrum antibiotic that has been used as a radiolabelled antibiotic in both the diagnosis of infections in rabbits and in clinical trials on humans. The diagnosis of skeletal microbial infections remains a challenge, especially in orthopaedic patients with implants. We present a case report of a patient with undiagnosed and unrelenting pain in the lower third of the left leg, which had persisted for 6 months. A novel scintigraphy, which was developed in-house using a 99mTC ciprofloxacin single vial kit, was used for diagnosing the active bacterial infection. A 99mTC methylene diphosphonate bone scan was also performed to locate precisely the site of the lesion. Gradually increasing concentrations of both the radiotracers confirmed the presence of active bacterial infection in the distal third of the left tibia. Follow-up scanning after antibiotic therapy showed the disappearance of the pooling of 99mTC ciprofloxacin, indicating a good response. Therefore, 99mTC ciprofloxacin has good diagnostic and prognostic applications in deep-seated covert skeletal microbial infections. However, the persistence of a focal concentration detected by the 99mTC methylene diphosphonate scan was attributed to the inflammatory and not the infective pathology.

Quinolone antibacterials are veterinary drugs authorized for use in food animal production. The analysis of residual amounts of drugs in food from animal origin is important for quality control of products for consumers. For this purpose, Maximum Residue Limits (MRLs) have been set up by a European Union Council Regulation on Veterinary Drug Residues (No. 90/2377/EEC and subsequent), and 8 quinolones received MRLs at concentration levels depending on both the matrix and the animal species of interest. A method was developed for screening and confirming 10 quinolone residues (ciprofloxacin, danofloxacin, difloxacin, enrofloxacin, flumequine, marbofloxacin, nalidixic acid, norfloxacin, oxolinic acid, sarafloxacin) in a wide variety of matrixes of different animal species. It involves extraction of the residues from the biological tissues/fluids by acidic aqueous solution, centrifugation and filtration prior to injection on a C18 narrow-bore column, and detection through a 3-step-mode fluorescence detector. The method was validated during a 2-week study for a set of 8 species-matrixes (i.e., bovine raw milk, bovine muscle, porcine muscle, porcine kidney, porcine liver, fish flesh and skin, poultry muscle, whole egg). Residues were quantified down to 15 microg/kg with limits of detection and quantitation ranging from 4 to 11 and 13 to 36 microg/kg, respectively, which are sufficient compared to the wide range of MRLs set for these substances (from 30 microg/kg for danofloxacin in milk to 1900 microg/kg for difloxacin in poultry liver). The limit of performance of the method in terms of CCalpha and CCbeta, the critical concentrations stated in the Decision No. 2002/657/EC and the ISO Standard No. 11843, has been calculated for the authorized (MRL) substances but only estimated in the case of the nonauthorized (non-MRL) substances.

An efficient multiresidue method for analysis of fluoroquinolones in shrimp has been developed in which quantitation by fluorescence and confirmation by Multiple Stage Mass Spectrometry (MS) is achieved simultaneously. In this method, shrimp tissue is extracted with ammoniacal acetonitrile and the extract is defatted and then evaporated. After dissolution in basic phosphate buffer, fluoroquinolones in the extract are separated by liquid chromatography and quantitated, taking advantage of their intense fluorescence. Eluate from the fluorescence detector enters the MS, which allows for confirmation by monitoring ratios of 2 prominent product ions in the MS3 or MS2 spectrum. Using this method, 8 fluoroquinolones have been analyzed in shrimp samples fortified at 10, 25, 50, or 100 ppb levels. Recoveries for desethyleneciprofloxacin, norfloxacin, ciprofloxacin, danofloxacin, enrofloxacin, orbifloxacin, sarafloxacin, and difloxacin ranged from 75 to 92%, with relative standard deviation values of <6%. The limits of quantitation ranged from 0.1 to 1 ng/g. Enrofloxacin and ciprofloxacin were also successfully determined in enrofloxacin-incurred shrimp using this method.

Pharmacokinetics of difloxacin and its distribution within the body fluids and endometrium of 6 mares were studied after intragastric (IG) administration of 5 individual doses. Difloxacin concentrations were serially measured in serum, urine, peritoneal fluid, synovial fluid, cerebrospinal fluid, and endometrium over 120 h. Bacterial susceptibility to difloxacin was determined for 174 equine pathogens over a 7-month period. Maximum serum concentration (Cmax) was 2.25 +/- 0.70 microg/mL at 3.12 +/- 2.63 h and Cmax after the 5th dose was 2.41 +/- 0.86 microg/mL at 97.86 +/- 1.45 h. The mean elimination half-life (t(1/2)) was 8.75 +/- 2.77 h and area under the serum concentration versus time curve (AUC) was 25.13 +/- 8.79 microg h/mL. Highest mean synovial fluid concentration was 1.26 +/- 0.49 microg/mL at 100 h. Highest mean peritoneal fluid concentration was 1.50 +/- 0.56 microg/mL at 98 h. Highest mean endometrial concentration was 0.78 +/- 0.48 microg/g at 97.5 h. Mean cerebrospinal fluid concentration was 0.87 +/- 0.52 microg/mL at 99 h. Highest mean urine concentration was 92.05 +/- 30.35 microg/mL at 104 h. All isolates of Salmonella spp. and Pasteurella spp. were susceptible. In general, gram-negative organisms were more susceptible than gram-positives. Difloxacin appears to be safe, adequately absorbed, and well distributed to body fluids and endometrial tissues of mares and may be useful in the treatment of susceptible bacterial infections in adult horses.

(99M)Tc-ciprofloxacin was used to image five adult camelids and a juvenile goat with clinical and/or radiographic signs of infection. (99m)Tc-ciprofloxacin (range 10-33 MBq/kg) was injected intravenously and a series of 2-min static images were acquired at 1- and 4-h postinjection. At 24-h postinjection, 5-min static images were acquired. Only the skull or abdomen was imaged in the adults; the whole body was imaged in the goat. The quality of the 1-, 4-, and 24-h studies was evaluated subjectively. Normal and abnormal areas of (99m)Tc-ciprofloxacin uptake were recorded and subjectively graded as mild, moderate or intense. Image quality was best 4-h postinjection. Twenty-four-hour images were poor because of insufficient radioactivity. (99m)Tc-ciprofloxacin imaging resulted in true positive or true negative scans in four of six animals. Two false-negative studies occurred. Intense (99m)Tc-cirofloxacin activity was seen in the lungs and urinary bladder, moderate/intense activity in the kidneys, and mild activity in the physes/epiphyses, liver and intermittently in the gastrointestinal tract. The normal distribution of (99m)Tc-ciprofloxacin in camelids/small ruminants differed from people. Further studies to determine the sensitivity and specificity of infection detection using (99m)Tc-ciprofloxacin in animals are warranted.

A reversed-phase high performance liquid chromatographic method with fluorescence detection was developed for the simultaneous analysis of ciprofloxacin, danofloxacin, enrofloxacin and sarafloxacin residues in edible chicken tissues. The analytes were extracted from chicken muscle, skin and fat, liver, kidney by aqueous potassium dihydrogenphosphate of different pH values through homogenization. The supernatant of the extract was applied onto a C18 solid phase extraction cartridge for clean-up. The separation was achieved on a C18 column, and the detection was performed with a fluorescence detector (excitation at 280 nm and emission at 450 nm). The four fluoroquinolones were analyzed in spiked samples of four chicken tissues with mean recoveries in the range of 53.9%-93.4% at spiked levels of 20-300 microg/kg. The relative standard deviations of inter-assay were no more than 23%. The detection limits of quantification were 20 microg/kg for ciprofloxacin, enrofloxacin and sarafloxacin and 4 microg/kg for danofloxacin. The method is simple, fast, and sufficient for routine analysis.

In this article there is an attempt, to critically review the literature referring to the clinical validity and clinical applications of in vivo imaging of infected areas of our body, with 99mTc-ciprofloxacin (infection). Infection is the product of labeling a broad spectrum antibiotic, ciprofloxacin, with 99mTc. There is increased interest and expectation that this agent will become a useful tool for every day clinical practice, in discriminating, infectious from inflammatory lesions. Although this radiopharmaceutical is not widely available, a number of papers have been published recently regarding clinical and experimental trials with this agent. There is some debate regarding its production procedure and its specificity in discriminating infection from inflammation. Comparison with other infection-imaging agents is described, as well as its clinical validity in specific clinical situations.

This study investigated the pharmacokinetic behaviour of difloxacin following a single intravenous (i.v.) bolus and intramuscular (i.m.) administration of 5 mg/kg body weight (bw) to rabbits (n = 6). Plasma concentrations were determined in triplicate by agar plate diffusion using E. coli (ATCC 25922) as the test organism. Difloxacin was assayed in plasma to determine its concentrations, kinetic behaviour and systemic availability. Plasma concentration-time data generated in the present study were analysed by non-compartmental methods based on statistical moment theory. Difloxacin was rapidly distributed to the tissues with a steady-state volume of distribution (Vdss) of 1.51 L/kg and the total body clearance (Cltot) was 0.59 L/kg/h. The elimination half-lives after i.v. and i.m. administration were 3.25 h and 3.82 h, respectively. After i.m. administration, difloxacin was rapidly absorbed, with mean peak plasma concentration (Cmax of 3.85 microg/ml achieved at 1.61 h (Tmax) post administration. The extent of plasma protein binding of difloxacin in rabbits was 21.45% and the systemic bioavailability was 95.29%.

Quinolones are important gyrase inhibitors. Even though they are used as active agents in many antibiotics, the detailed mechanism of action on a molecular level is so far not known. It is of greatest interest to shed light on this drug-target interaction to provide useful information in the fight against growing resistances and obtain new insights for the development of new powerful drugs. To reach this goal, on a first step it is essential to understand the structural characteristics of the drugs and the effects that are caused by the environment in detail. In this work we report on Raman spectroscopical investigations of a variety of gyrase inhibitors (nalidixic acid, oxolinic acid, cinoxacin, flumequine, norfloxacin, ciprofloxacin, lomefloxacin, ofloxacin, enoxacin, sarafloxacin and moxifloxacin) by means of micro-Raman spectroscopy excited with various excitation wavelengths, both in the off-resonance region (532, 633, 830 and 1064 nm) and in the resonance region (resonance Raman spectroscopy at 244, 257 and 275 nm). Furthermore DFT calculations were performed to assign the vibrational modes, as well as for an identification of intramolecular hydrogen bonding motifs. The effect of small changes in the drug environment was studied by adding successively small amounts of water until physiological low concentrations of the drugs in aqueous solution were obtained. At these low concentrations resonance Raman spectroscopy proved to be a useful and sensitive technique. Supplementary information was obtained from IR and UV/vis spectroscopy.

The absorption kinetics of sarafloxacin, as a model of fluoroquinolone structure, were studied in the rat small intestine and in Caco-2 cells. The objective of the study was to investigate the mechanistic basis of the drug's intestinal transport in comparison with other members of the fluoroquinolone family and to apply a mathematical modelling approach to the transport process. In the rat small intestine, sarafloxacin showed dual mechanisms of intestinal absorption with a passive diffusional component and an absorptive carrier-mediated component. The characteristics of the animal study design made it suitable for population analysis, thus allowing the accurate estimation of transport parameters and their inter and intra-individual variances. The transport system in the rat model was ATP-dependent, as sodium azide was able to decrease the absorption rate constant in a concentration-dependent fashion. The inhibition mechanism of sodium azide was modelled based on its ATP depletion capacity. The rationale of this approach was to consider the inhibitor-carrier interaction as a concentration- dependent response. This interaction was accurately described by a non-competitive mechanism. In Caco-2 cells, sarafloxacin showed a concentration dependent permeability in both directions apical to basal, and basal to apical. The permeability values and ratios of permeability values at different concentrations suggested the presence of two carriers (absorption and efflux carriers). The passive diffusion component in both systems was compared to that predicted by the absorption-partition correlation, previously established for two series of fluoroquinolones. The discrepancy between the experimental and predicted value suggested the presence of an efflux mechanism similar to that already described for other fluoroquinolones. The differences and similarities of the in situ and the in vitro results are discussed as well as the usefulness of the modelling approach.

Background/aims: The aim of the study is detection and evaluation of the abdominal and gastrointestinal infective foci using 99mTc-ciprofloxacin (Laboratory for radioactive isotopes, Vinca)., Methodology: In total 21 patients with clinical suspicion on abdominal or gastrointestinal infection were investigated. In all the patients, planar liver/spleen scintigraphy was performed. Ciprofloxacin chloride (3.5 mg) was mixed with 555 MBq of 99mTc in 3 mL of physiological solution and incubated for 20 min. After slow i.v. injection in a cubital vein, dynamic acquisition (1 f/min) was performed during the first 60 min in the position of interest, followed by static acquisition (500,000 imp) anterior and posterior view, abdomen and pelvis after 1 h and 4 h in all patients. When necessary, additional scintigrams were acquired after 24 h. In all the patients with negative or equivocal findings of planar scintigraphy, emission computerized tomography (SPECT) was performed (60 positions, 6 degrees). Interpretation was made by three independent observers. Additional data were provided using clinical findings, ultrasonography, computed tomography and magnetic resonance imaging, laboratory analyses, and surgical or microbiological confirmation of infection., Results: There were eleven true-positive findings, seven true negative, two were false negative while one was false positive due to intestinal obstruction. Sensitivity was 79%, specificity 91%, positive predictive value 92%, negative predictive value 77%, accuracy 84%., Conclusions: According to our results, scintigraphy with radiolabeled ciprofloxacin is a useful method for detection and assessment of exact localization of abdominal and gastrointestinal infections.

Aim: To study the synthesis and antibacterial activity of ciprofloxacin derivatives., Methods: Ciprofloxacin derivatives were synthesized primarily from 2-methyl-5-nitroimidazol and ciprofloxacin through nucleophilic substitution. The antibacterial activity of the synthesized compounds were tested., Results: Nine new compounds were synthesized. The structure of the title compounds were confirmed by 1H NMR, MS and element analysis., Conclusion: Compounds II, IVC and IVD showed appreciable antibacterial activity, and were worth further studying.

A simple and sensitive HPLC method has been developed for the simultaneous determination of enrofloxacin (ENR) and ciprofloxacin (CIP) in pig tissue using difloxacin (DIF) as internal standard. Tissue sample preparations were carried out by adding phosphate buffer (pH 7.4, 0.1 m), followed by extraction with trichloromethane. Fluoroquinolones were separated on a reversed-phase column and eluted with aqueous buffer solution-acetonitrile (80:20, v/v). The concentrations of CIP, ENR and DIF eluted from the column, with retention times of 2.20, 2.73 and 4.38 min, respectively, were monitored by fluorescence detection at lambda(ex) 276 and lambda(em) 442 nm. The detection and quantitation limit were 8 and 25 ng/g, respectively, for both compounds. Standard curves were linearly related to concentration in the range 25-400 ng/g. The consequences of the introduction of minor reasonable variations (ruggedness studies) have also been analysed. Finally, the measurement of the tissue levels of ENR and CIP in the pig tissues after oral administration confirmed the utility of the proposed method.

The aim of the study is detection and evaluation of the orthopedic infections using 99mTc-ciprofloxacin, radiopharmaceutical supposed to distinguish inflammation from infection. There were 15 true positive findings, 9 true negative, and two were false positive, while 1 was false negative. Sensitivity was 94%, specificity 82%, positive predictive value 88%, negative predictive value 90% and accuracy 89%. According to our results, scintigraphy with 99mTc-ciprofloxacin is a useful method for detection and assessment of exact localization of orthopedic infections, which might be useful for (differential) diagnosis, surgical treatment in due time as well as monitoring of the treatment of conservative therapy.

Intravenously injected 99mTc ciprofloxacin is rapidly accumulated and washed from the septic focus. Lymphotropic injections provide targeted and long-lasting effect of the antibiotic. After injection into the interspinous ligament the drug slowly enters the inflammation area (by-passing the urinary organs and liver), where it is maximally accumulated only after 24 h, which allows to reduce the number of injections and the total dose of the antibiotic.

Data on clinical and microbiological study on 40 patients showed sufficient efficacy of combined preparation Cifran CT used in combined therapy of inflammatory periodontal disease.

Clinical and microbiological efficacy of Cifran OD (Ranbaxy, India), a formulation with prolonged action and extended release of ciprofloxacin was studied in 22 patients with bacteriuria and lingering diabetes mellitus. Ciprofloxacin was used in doses of 500 or 1000 mg orally once a day depending on the severity of the disease singns for 2-3 weeks as etiotropic therapy and only in 2 cases with severe pyelonephritis it was used intravenously drop-wise and orally simultaneously. Twenty eight microbial strains isolated from urea of the patients were tested. The main species of the isolates belonged to the family Enterobacteriaceae. Twenty five isolates (89.3%) were susceptible to ciprofloxacin and 3 isolates (10.7%) were resistant. The clinical efficacy of ciprofloxacin was 90.9%.

The studies were conducted on noninfected and Escherichia (E) coli-infected mice treated with orbifloxacin administered orally 10 times at 24-hr intervals at a dose of 2.5 mg/kg. Orbifloxacin did not change the activity of peritoneal macrophages in noninfected mice. Administration of orbifloxacin in E. coli-infected mice modulated the effects of infection on the percentage of phagocyting macrophages, the percentage of NBT-positive cells, and nitric oxide production. Orbifloxacin did not affect the synthesis and release of interleukin-1 by macrophages. Orbifloxacin exerted a modulating effect on the subsets of lymphocytes in thymus, spleen, and mesenteric lymph node cells in noninfected and E. coli-infected mice.

Unlabelled: The use of (99m)Tc-ciprofloxacin as a tracer for infection and inflammation has been examined and discussed in the literature extensively. Its alleged ability to discriminate between sterile inflammation and bacterial versus nonbacterial infections has led to an intense debate. Other labeled fluoroquinolones might offer better characteristics or may add to a better understanding of the working mechanism of (99m)Tc-ciprofloxacin. The rationale of this work was to determine possible differences in the use of 2 labeled quinolones--that is, (99m)Tc-ciprofloxacin and (99m)Tc-enrofloxacin--as tracers for infection and inflammation in animals., Methods: Ciprofloxacin and enrofloxacin were labeled with (99m)Tc and characterized. The stability of both preparations was evaluated in serum and in the presence of an excess of cysteine. In vitro binding studies were performed to determine the interaction of the labeled quinolones with bacteria and other cells. Rats with sterile and infectious intramuscular lesions were used to study the scintigraphic properties of the 2 compounds. To assess the specificity of binding to living bacteria, infectious intramuscular lesions of heat-killed Staphylococcus aureus and Candida albicans were used as controls. Imaging was performed with a gamma-camera at 0, 3, 5, and 22 h after injection., Results: The radiochemical purity of both radiolabeled fluoroquinolones exceeded 95% as determined by instant thin-layer chromatography. Both compounds were moderately stable in serum. Binding assays did not show any saturable binding to S. aureus, heat-killed S. aureus, as well as C. albicans. None of the tracers showed specific binding to bacteria. Scintigraphy showed uptake in the infectious lesion at 1 h after injection, which washed out during the next 4 h. Abscess-to-muscle ratios for both preparations were not significantly different for the various infectious or inflammatory lesions studied and did not exceed an average of 4.25 +/- 0.62., Conclusion: The study demonstrated that (99m)Tc-ciprofloxacin and (99m)Tc-enrofloxacin do not show preferential binding to living bacteria. In vivo (99m)Tc-enrofloxacin has similar characteristics as (99m)Tc-ciprofloxacin except for differences in uptake in a few normal tissues.

A simple and rapid reversed-phase high-performance liquid chromatographic method for separation and determination of process-related impurities of difloxacin (DFL) was developed. The separation was achieved on a reversed-phase C(18) column using methanol-water-acetic acid (78:21.9:0.1, v/v/v) as a mobile solvent at a flow rate of 1.0 ml/min at 28 degrees C using UV detection at 230 nm. It was linear over a range of 0.03 x 10(-6) to 1.60 x 10(-6)g for process related impurities and 0.05 x 10(-6) to 2.40 x 10(-6)g for difloxacin. The detection limits were 0.009 x 10(-6) to 0.024 x 10(-6)g for all the compounds examined. The recoveries were found to be in the range of 97.6-102.0% for impurities as well as difloxacin. The precision and robustness of the method were evaluated. It was used for not only quality assurance, but also monitoring the synthetic reactions involved in the process development work of difloxacin. The method was found to be specific, precise and reliable for the determination of unreacted levels of raw materials, intermediates in the reaction mixtures and the finished products of difloxacin.

A simple method was developed for the simultaneous determination of seven quinolones (enoxacin, ofloxacin, ciprofloxacin, danofloxacin, lomefloxacin, enrofloxacin and sarafloxacin) in foods using liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The seven quinolones were extracted with acetonitrile containing 0.2% formic acid, and the extracted solution was cleaned up on a C18 cartridge. The extract was diluted with 5 mmol/L IPCC-MS3 for injection into the LC-ESI-MS/MS. The LC separation was carried out on an ODS column with gradient elution of 5 mmol/L IPCC-MS3-acetonitrile as the mobile phase. Mass spectral acquisition was done in the positive ion mode by applying selected reaction monitoring (SRM). The recoveries of the seven quinolones were mostly greater than 60% from foods fortified at 10 ng/g. The detection limits in foods were 2 ng/g for enoxacin and ciprofloxacin, and 1 ng/g for the other drugs. Twenty cattle muscle, 7 swine muscle, 9 chicken muscle, 16 milk, 19 prawn and 20 broiled eel samples from retail markets were analyzed by this method. Enrofloxacin and its metabolite ciprofloxacin were detected in 9 broiled eel at the level of trace (tr)-34 ng/g and tr-10 ng/g, respectively.

The objective of the study was to evaluate the in vitro activity of orbifloxacin against Staphylococcus intermedius strains isolated in France from canine skin and ear infections. The minimum inhibitory concentrations (MICs) of orbifloxacin against 240 field S. intermedius isolates (69 skin and 171 ear isolates) ranged from 0.016 to 8 mg l(-1), with MIC50 and MIC90 equal to 0.5 and 1 mg l(-1), respectively. Only one strain, a pyoderma isolate was resistant (MIC=8 mg l(-1)). Orbifloxacin was tested at different concentrations for killing rate against five isolates obtained from pyoderma cases and against a reference strain (Staphylococcus aureus ATCC 29213). Orbifloxacin expressed a concentration-dependent bactericidal activity against the S. aureus reference strain, but a time-dependent bactericidal activity against S. intermedius. Orbifloxacin induced bactericidal effect against the S. intermedius strains tested with concentrations equal to or two times MIC.

A suspension formulation containing sarafloxacin HCl, triamcinolone acetonide, and clotrimazole was developed for the treatment of otitis externa in dogs. The potency for the three active ingredients in this suspension was monitored at 25 degrees C and 40 degrees C for up to 3 months. The potencies of triamcinolone and clotrimazole were found unchanged, but the potency of sarafloxacin HCl in the samples stored at 40 degrees C for 1 month varied significantly between samples. However, assay inconsistency for sarafloxacin HCl was not seen in samples stored at 25 degrees C. Under an optical microscope, large crystals were found in the 40 degrees C stability samples but not in the 25 degrees C samples. The large crystals in 40 degrees C samples were identified as sarafloxacin by high-performance liquid chromatography (HPLC). This finding suggests that crystal growth of sarafloxacin took place at 40 degrees C during storage, leading to the formation of larger crystals and the consequent sampling nonuniformity and assay inconsistency. The solid-state properties of these crystals were further evaluated using hot-stage microscopy and Fourier transform infrared (FTIR) analysis. The results indicate that the crystal growth of sarafloxacin was most likely attributed to a change in the hydration form of sarafloxacin.

WM5, a 6-aminoquinolone derivative, binds with high affinity to the bulge of the trans-activation-responsive region (TAR), whereas it displays low binding affinity for the loop and stem regions of TAR and for random RNA and DNA sequences. Furthermore, WM5 disrupts the natural protein-nucleic acid complex with a 50% inhibitory concentration in the low micromolar range in both in vitro and in vivo assays.

DRAXIMAGE, under exclusive licence from BTG International Ltd, is developing a technetium-99m formulation of ciprofloxacin (INFECTON), as a radioimaging agent for the potential diagnosis of infection, including fever of unknown origin, osteomyelitis, wound infection, abdominal abscess, pneumonia, appendicitis and tuberculosis.

Background: The non-invasive assessment of postoperative spinal infections can pose a substantial diagnostic challenge, especially in the presence of orthopaedic devices. In contrast to white blood cell scanning, which is of limited use in the spine, the low uptake of 99mTc ciprofloxacin into normal bone marrow, combined with its claimed bacterial specificity, makes it, theoretically, an ideal candidate for evaluating postoperative spinal infections., Aim: This study aimed to evaluate 99mTc ciprofloxacin planar and single photon emission tomography (SPET) imaging in relation to microbiological diagnosis in the postoperative spine., Methods: Only patients with a microbiologically confirmed diagnosis were included in this analysis. Planar imaging was performed at 1, 3 and 24 h, and SPET was performed at 3 h post-injection of 370 MBq 99mTc ciprofloxacin. Images were scored by two independent, certified, nuclear medicine physicians, blinded for the final diagnosis., Results: Within the first 22 consecutive patients with microbiological diagnosis, there were nine deep infections. Sensitivity, specificity and accuracy at visual scoring were, respectively, 67%, 77%, 73% (1 h), 78%, 69%, 73% (3 h), and 56%, 92%, 77% (24 h) for planar imaging, and 100%, 54%, and 73% for SPET., Conclusion: In contrast to white blood cell scanning, SPET with Tc ciprofloxacin is sensitive in evaluating infections in the postoperative spine. Sensitivity is higher for SPET than for planar imaging. However, the results presented prove that its specificity is limited, especially in patients who have recently (< 6 months) undergone surgery. Taken this limitation into account, we advise planar and SPET imaging at 3 h post-injection and at an interval of at least 6 months after surgery to minimize the chance for false positives.

The cultural, physiologo-biochemical adhesive and antagonistic properties of B. subtilis strains with good prospects for use as biotherapeutic preparations were studied. For further studies B. subtilis strain No. 1719 was chosen. In experiments on non-inbred white mice the animals were treated by the preparation Cifran used for their selective decontamination from opportunistic microflora and for the creation of the state of dysbiosis. The influence of the spore-forming microbe on the parietal microflora of the large intestine of the animals was shown. Reliable data on the changes in the number of microorganisms (CFU/ml) per 1 cm of the surface of the large intestine were established. As markers making it possible to evaluate the action of biotherapeutic and other medicinal remedies, easily determinable ratios of lac+/lac- of bacteria and Staphylococcus aureus/Staphylococcus spp. was proposed.

The non-invasive assessment of postoperative spinal infections can pose a substantial diagnostic challenge, especially in the presence of orthopaedic devices. Whereas white blood cell scanning is of limited use in the spine, the low normal bone marrow uptake of technetium-99m ciprofloxacin combined with its claimed bacterial specificity makes it theoretically an ideal candidate for the evaluation of postoperative spinal infections. This study aimed to evaluate 99mTc-ciprofloxacin planar and single-photon emission tomography (SPET) imaging in relation to microbiological and clinical diagnosis in the postoperative spine. Planar imaging was performed at 1, 3 and 24 h and SPET was performed at 3 h post injection of 370 MBq 99mTc-ciprofloxacin. Images were scored by two independent certified nuclear medicine physicians, blinded to the final diagnosis. Within the 48 patients, there were 13 deep infections. Sensitivity, specificity and accuracy at visual scoring were respectively 54%, 71% and 67% (1 h), 62%, 77% and 73% (3 h), 42%, 91% and 77% (24 h) for planar imaging and 100%, 74% and 81% for SPET. When recently operated patients (< 6 months) were excluded, the specificity of the SPET imaging rose to 81%. In conclusion, unlike white blood cell scanning, 99mTc-ciprofloxacin SPET is sensitive in evaluating infections in the postoperative spine. Sensitivity is much higher for SPET than for planar imaging. However, the results presented prove that its specificity is limited, especially in recently operated patients. Taking this limitation into account, we advise planar and SPET imaging at 3 h post injection and an interval of at least 6 months after surgery to minimise the likelihood of false positives.

We report the first feline case of Bartonella henselae endocarditis. Despite negative blood cultures, the cat had high Bartonella antibody titers and B. henselae type I DNA was detected in the damaged aortic valve. Microscopic examination of the valve revealed endocarditis with small silver positive coccoid structures in endothelial cells.

Objective: To study the frequency of technetium-99m-positive ciprofloxacin scans (Infecton scintigraphy) thought to be specific for bacterial DNA in patients with arthritis and to assess the clinical relevance of positive scans., Methods: Four groups of adults with arthritis were studied. Group 1: 53 patients with inflammatory arthritis, 36 with spondylarthropathy (SpA) and 17 with rheumatoid arthritis (RA); group 2: five patients with crystal arthropathy; group 3: those patients with osteoarthritis (OA) of the knee, wrist or spine; and group 4: 28 patients who had no arthritis but were being investigated for renal infection. Patients were injected with 10 mCi 99Tcm-ciprofloxacin with isotope uptake analysis at 4 h. Clinically swollen joints were assessed by a rheumatologist and the positive scans assessed by a physician in nuclear medicine., Results: Increased Infecton uptake was noted in inflamed joints independent of the pathology. It was seen in 10 of 17 patients with SpA, 12 of 17 with RA, all five with crystal arthropathy, eight with knee OA, two with wrist OA, none with spinal OA and none in uninflamed joints. A close correlation between clinically swollen joints and articular Infecton uptake was noted (P = 0.0003), with the uptake being in the distribution of the synovial perimeter. Additional uptake was noted in the abdomen (n = 9) and pulmonary region (n = 2) of SpA patients., Conclusion: The Infecton scan is not specific for infection but may be a reliable procedure for identifying the presence and distribution of the inflammation within joints. It has the potential for monitoring the response of inflamed joints to treatment.

Aim: To investigate the value of Tc-99m ciprofloxacin imaging in the differential diagnosis of chronic bacterial prostatitis., Methods: The study included 4 normal subjects as the negative controls, 2 patients with acute prostatitis or cystourethritis as the positive controls and 59 patients diagnosed as chronic bacterial prostatitis or chronic pelvic pain syndrome by traditional laboratory tests. In every subject, the single photon emission computerized tomography images were obtained 3 h after intravenous injection of Tc-99m Ciprofloxacin. The results of the imaging were compared with those of laboratory tests., Results: On the images, negative uptake was observed in all normal subjects, while strong hot uptake, in the whole prostate of acute prostatitis patients and in the whole urethra of acute cystourethritis patients. In 13 (68%) of 19 patients categorized as chronic bacterial prostatitis by standard laboratory tests, hot uptake with less intensity than that of acute prostatitis was observed in the prostate area around the prostatic urethra. Negative uptake in the prostate was observed in 6 of 19 patients (32%) categorized as chronic bacterial prostatitis. Interestingly, hot uptake in the prostate was exhibited in 28 (70%) of the 40 patients categorized as chronic pelvic pain syndrome., Conclusion: Tc-99m ciprofloxacin imaging is helpful in the differential diagnosis of prostatitis syndrome.