Godfrey LaFerla

A simple HPLC-UV method for the determination of ciprofloxacin in human plasma

A rapid and sensitive HPLC-UV method for the determination of ciprofloxacin in human plasma is described. Protein precipitation with acetonitrile was used to separate the drug from plasma protein. An ACE(®) 5 C18 column (250 mm×4.6 mm, 5 μm) with an isocratic mobile phase consisting of phosphate buffer (pH 2.7) and acetonitrile (77:23, v/v) was used for separation. The UV detector was set at 277 nm. The method was validated in the linear range of 0.05-8 μg/ml with acceptable inter- and intra-assay precision, accuracy and stability. The method is simple and rapid and can be used to quantify this widely used antibiotic in the plasma of patients suffering from Peripheral Arterial Disease.

Factors Affecting Gentamicin Penetration in Lower Extremity Ischemic Tissues With Ulcers

The aims of the study were to analyze the penetration of gentamicin in foot ulcers in patients with different severities of peripheral arterial disease (PAD) and to determine significant parameters affecting lower limb tissue concentrations. Patients undergoing debridement of a wound or an amputation procedure were included. All patients received a 120 mg or 240 mg intravenous dose of gentamicin prior to the procedure. Patients were classified according to the degree of PAD. Tissue and serum samples were collected at the time of intervention, and gentamicin concentrations were determined by fluorescence polarization immunoassay. Blood and tissue samples were taken from 61 patients, 41 males and 20 females with a mean age of 66 years. Nineteen patients had nil or borderline PAD, 9 patients had mild or moderate PAD, and 26 patients had severe PAD. Forty-eight patients had type 2 diabetes, 8 patients had type 1 diabetes, and 5 patients were nondiabetic. The concentration of gentamicin in peripheral skeletal muscle tissue was dependent on the serum concentration, degree of PAD, gender, and age. For patients with ischemic lower extremity wounds (patients with mild, moderate, and severe PAD), the concentration of gentamicin was significantly lower (P = .010) than the concentration in nonischemic wounds, and the concentration in female patients was also significantly lower than in male patients (P = .047). The concentration in peripheral subcutaneous tissue was 0.663 times the concentration in skeletal muscle tissue (P < .00001). Gentamicin showed greatest penetration in male patients without PAD. For patients with severe PAD, higher doses of gentamicin may be required to achieve the same effect.

Factors Affecting Penetration of Ciprofloxacin in Lower Extremity Ischemic Tissues

The aims of this study were to evaluate factors influencing the distribution of ciprofloxacin in tissue of patients suffering from varying degrees of peripheral arterial disease (PAD). Blood and tissue samples were collected from patients undergoing debridement or amputation procedures and the amount of ciprofloxacin in them was determined using high-performance liquid chromatography. All patients were administered a 200-mg dose of intravenous ciprofloxacin prior to the debridement or amputation procedure. Data, including patient gender, age, type of diabetes, presence of neuropathy, medications taken, and severity of PAD were collected. These data were then analyzed to determine factors influencing the concentrations of ciprofloxacin in tissue of the lower limbs. The Kruskal-Wallis test, Spearman correlation, and chi-square test were used to relate covariates and fixed factors with the concentration of ciprofloxacin in tissue. Following bivariate analysis, a 3-predictor regression model was fitted to predict tissue concentrations of ciprofloxacin given information about these predictors. Blood and tissue samples were collected from 50 patients having an average age of 68 years. Thirty-three patients were males and 35 patients suffered from type 2 diabetes. The average number of medications that these patients were taking was 10. The majority of patients (n = 35) were suffering from severe PAD. Tissue concentrations of ciprofloxacin were mainly related to plasma concentrations of ciprofloxacin, number of medications that the patients were taking and severity of PAD.

CP-129 Concentration of ciprofloxacin in tissue of patients suffering from peripheral arterial disease

Background Peripheral arterial disease (PAD) is a common atherosclerotic condition and can lead to cardiovascular complications. Patients suffering from this disease can develop foot infections, and often debridement or amputation procedures due to poor healing of the wounds are required. Ciprofloxacin is a commonly administered antibacterial in patients with PAD. Purpose To quantify ciprofloxacin concentrations in peripheral tissues of patients suffering from varying degrees of PAD to assess whether disease severity significantly affected therapeutic concentrations of ciprofloxacin reaching the site of infection. Material and methods Tissue samples were collected from 50 PAD patients admitted for debridement or amputation procedures. The severity of PAD was assessed by a vascular surgeon using ankle brachial pressure indices and spectral waveform analyses. Tissue samples were collected at the end of the debridement or amputation procedure, which normally took 20 min, homogenised and the amount of ciprofloxacin in each analysed using high performance liquid chromatography. The Mann-Whitney test was applied to correlate between the different types of PAD severity and tissue concentrations achieved. Results 50 patient samples (33 male; 17 female) were analysed. 44 patients were admitted for an amputation and 6 for a debridement procedure. 34 patients were suffering from severe PAD, 3 patients had no or borderline PAD while 12 patients had mild to moderate PAD. Patients having the lowest concentration of ciprofloxacin were those suffering from severe PAD. The mean concentration of ciprofloxacin in the tissue of patients suffering from severe PAD, mild to moderate PAD and none to borderline PAD was 0.11 µg/mL, 0.42 µg/mL and 1.54 µg/mL, respectively. Pairwise comparison results between the different types of PAD severities indicated that there was a significant difference in the concentration of ciprofloxacin reaching the tissue. Conclusion The severity of PAD is a significant predictor of the concentration of ciprofloxacin in peripheral tissue. Giving higher doses of ciprofloxacin to try and attain greater concentrations in ischaemic tissue might not result in increased tissue ciprofloxacin concentrations in patients with severe states of PAD. References and/or Acknowledgements Thanks to the staff at the surgical ward, operating theatre and toxicology department. No conflict of interest.

Crohn's disease manifesting as an isolated cecal polyp and secondary appendiceal obstruction with histologically normal bowel.

Dear Editor:Inflammatory colonic polyps usually arise on a backgroundhistory of an inflamed colon such as Crohn’s disease orulcerative colitis [1]. Similar inflammatory bowel disease(IBD)-related inflammatory polyps, occurring in the absenceof background IBD, have manifested themselves as eitherfiliform polyposis [2] or localized giant inflammatory polyps[3]. We hereby report a case of an isolated sessile cecal poleinflammatory polyp, with histological features of Crohn’sdisease, without a history or current evidence of backgroundIBD. To our knowledge, our case is the first case of such amanifestation of a common condition. Moreover, this polypalso caused secondary appendiceal obstruction, another find-ing previously unreported.A 33-year-old male, nonsmoker, presented with a 6-monthhistory of intermittent colicky right iliac fossa (RIF) pain,which spontaneously resolves after 2 days of rest. He did notreport any change in bowel habit, rectal bleeding, fever, orweight loss. His past medical history, surgical history, familyhistory, and social history were unremarkable. Examinationrevealed normal findings. No tenderness or masses were elic-ited on palpation of the abdomen. Laboratory investigationsrevealeda normal fullblood count and inflammatory markersduring pain-free periods but an elevated C-reactive protein(95mg/l)andhyperferritinemia(681ng/ml)wheninpain.Hehad normal renal, liver, iron, folate, and vitamin B

PWE-107 Osteoporosis in Crohn’S Disease Patients Expressing an Autophagy-Related Atg16L1 Gene Variant

Introduction Osteoporosis is common in Crohn’s disease patients.1 Autophagy genes have so far never being studied as potential risk factors for osteoporosis in Crohn›s disease. Methods We have analysed the risk for osteoporosis among Crohn’s disease patients expressing the rs2241880 polymorphism of the ATG16L1 gene. Patients diagnosed with Crohn’s disase through histological, radiological and endoscopic findings were recruited. A blood sample for genotyping was taken and a DEXA Bone Density scan was performed in each patient. Genotyping for this variant involved: – DNA extraction – Gradient Polymerase Chain Reaction (PCR) – Quantitative PCR and High Resolution Melt (HRM) – Restriction Fragment Length Polymorphism (RFLP) of PCR product Results 83 Crohn’s patients were included in the study. Following genotyping, 33 patients were found to have no mutation (wild type), 44 were heterozygous and 6 were homozygous for the rs2241880 variant of the ATG16L1 gene. The table below shows the mean T and Z scores at the hip and spine of patients with the wild type, heterozygous and homozygous variants. Patients Homozygous for the rs2241880 variant had lower mean T and Z scores at the hip than those Heterozygous or Wild Type. Using t-test, there was no statistical difference between the Homozygous, Heterozygous and Wild Type patients’ hip T scores (p:0.314), Z scores (p:0.441), and spine T scores (p:0.751) and Z scores (p:0.822). Using χ2 test, the relationship between the 3 different variants (homozygous, heterozygous and wild type) and the risk of osteoporosis (T score < –2.5), osteopoenia (T score: –1.0 to –2.5) and normal (Tscore > –1.0) was not statistically significant (p:0.978). Conclusion We found no significant difference between the T and Z scores of patients with ATG16L1 Homozygous, Heterozygous and Wild Type alleles. However, there is a trend in the mean T and Z scores at the hip with lower scores in patients with Heterozygous/Homozygous alleles. Such a trend is not present in the spine. While the authors can offer no explanation for this difference, studies on larger populations are needed to better investigate the relationship between ATG16L1 mutations and the risk of osteoporosis. Abstract PWE-107 Table rs2241880 variant of ATG16L1 (95% Confidence Interval) T Score, Hip T Score, Spine Z Score, Hip Z Score, Spine Wild Type (n = 33) -1.48 (–1.91 - –1.05) -0.96 (–1.41 - –0.51) -0.75 (–1.20 - –0.31) -0.45 (–0.91 -+0.01) Heterozygous (n = 44) -1.68 (–2.32 - –1.22) -0.94 (–1.41 - –0.47) -0.92 (–1.38- –0.46) -0.34 (–0.82 - +0.14) Homozygous (n = 6) -1.84 (–2.71 - –0.97) -0.14 (–1.10- 0.82) -0.99 (–1.86 - –0.14 -0.34 (–0.62 - +1.33) Disclosure of Interest None Declared. Reference Lewis NR, Scott BB. British Society Guidelines for osteoporosis in inflammatory bowel disease and celiac diseas. BSG guidelines in Gastroenterology. June 2007; 1–12.