QuEChERS methodologies as an alternative to solid phase extraction (SPE) for the determination and characterisation of residues of cephalosporins in beef muscle using LC-MS/MS

This work was focused on the comparison of two clean-up methods to be used for the simultaneous determination of seven cephalosporins in cow muscle. In particular, the performance of novel dispersive solid phase extraction (d-SPE) procedures based on QuEChERS methodologies was assessed and compared with conventional SPE. The separation and detection of the analytes using both methods was carried out by LC-MS/MS to reach enough sensitivity to be compatible with the detection of the maximum residue limits (MRL) of cephalosporins as regulated by EU directives. The optimization of the clean-up step relied on experimental design in order to find the most suitable conditions with a reduced number of assays. Besides, multi-objective responses were used to reach an overall compromise in the recovery of all analytes simultaneously. The validation of the two methods was done according to the Directive 2002/657/EC. Linearity, decision limit, detection capability, detection and quantification limits (4-50 μg kg⁻¹), precision (RSD less than 15% except for PIR) and recoveries were determined and adequate results with comparable values using QuEChERS and SPE methodologies. LOQ were better for SPE method (0.1-10 μg kg⁻¹) but both methods show LOQ below MRL values. Precision was slightly better for the QuEChERS method, that also presents better recoveries, higher than 85% except for cephalexin

Can routine peripheral blood counts like neutrophil-to-lymphocyte ratio be beneficial in prediagnosis of testicular cancer and its stages?

Background: The purpose of this study was to assess the diagnostic role of preoperative hematological parameters, especially neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and mean platelet volume (MPV) in germ cell testicular malignancies and their prediagnostic role in staging of testicular cancer. Materials and Methods: In this cross-sectional retrospective study, we analyzed 39 patients who underwent radical orchiectomy due to a testicular cancer (Group 1) and 82 patients on whom varicocelectomy procedure was performed as control group (Group 2) between January 2006 and January 2016 in our clinic. Evaluation of the preoperative hematological parameters in both groups and also the subgroups in malignancy group according to histopathological stages was conducted in this study. Results: When the hematological parameters were compared, a statistically significant difference was found between the two groups in terms of neutrophil counts, NLR, PLR, and MPV. NLR and PLR were significantly higher and MPV was significantly lower in testicular cancer group compared to the control group. NLR was 3.1 ± 1.4 and 2.0 ± 1.5, PLR was 141.3 ± 53.2 and 115.7 ± 44.8, and MPV was 8.9 ± 1.0 and 9.3 ± 1.1 for testicular cancer and control groups, respectively (P < 0.05). Furthermore, differences were observed between only mean corpuscular volume, mean corpuscular hemoglobin, and MPV (P < 0.05) in different stages of malignancy. Conclusion: In accordance with these findings, NLR, PLR, and MPV may be helpful for prediagnosis of testicular malignancies. Hematological parameters will become important in the preoperative assessment for those patients

Voltammetric detection of sequence-selective DNA hybridization related to Toxoplasma gondii in PCR amplicons

WOS: 000368866900031PubMed ID: 26717837This work describes the single-use electrochemical DNA biosensor technology developed for voltammetric detection of sequence selective DNA hybridization related to important human and veterinary pathogen; Toxoplasma gondii. In the principle of electrochemical label-free detection assay, the duplex of DNA hybrid formation was detected by measuring guanine oxidation signal occured in the presence of DNA hybridization. The biosensor design consisted of the immobilization of an inosine-modified (guanine-free) probe onto the surface of pencil graphite electrode (PGE), and the detection of the duplex formation in connection with the differential pulse voltammetry(DPV) by measuring the guanine signal. Toxoplasma gondii capture probe was firstly immobilized onto the surface of the activated PGE by wet adsorption. The extent of hybridization at PGE surface between the probe and the target was then determined by measuring the guanine signal observed at +1.0 V. The electrochemical monitoring of optimum DNA hybridization has been performed in the target concentration of 40 mu g/mL in 50 min of hybridization time. The specificity of the electrochemical biosensor was then tested using non-complementary, or mismatch short DNA sequences. Under the optimum conditions, the guanine oxidation signal indicating full hybridization was measured in various target concentration from 0.5 to 25 mu g/mL and a detection limit was found to be 1.78 mu g/mL. This single-use biosensor platform was successfully applied for the voltammetric detection of DNA hybridization related to Toxoplasma gondii in PCR amplicons. (C) 2015 Elsevier B.V. All rights reserved.Cumhuriyet UniversityCumhuriyet University [EGT 022]The authors greatly acknowledge the financial support from Cumhuriyet University (project no: EGT 022)

In-vitro effects of PDE5 inhibitor and statin treatment on the contractile responses of experimental MetS rabbit's cavernous smooth muscle

Objective: Hypercholesterolaemia promotes erectile dysfunction through increased superoxide formation and decreased nitric oxide bioactivity in cavernosal tissue. The role of nitric oxide on erectile function is well known. Statins have lipid lowering properties and can modulate endothelial nitric oxide bioavailability. Sildenafil, enhances smooth muscle relaxation in corpus cavernosum. We invastigated in-vitro effects of sildenafil and rosuvastatin on nonadrenergic, non-cholinergic and nitric oxide mediated cavernosal smooth musle relaxation in metabolic syndrome rabbits, since alterations in this pathway are recognised in diabetic and hypercholesterolemic erectile dysfunction. Methods: Ten male rabbits were fed a standart diet as control group, fourty male rabbits were fed a hypercholesterolemic diet for 12 weeks. Hypercholesterolemic group were divided for without treatment, rosuvastatin treatment, sildenafil teratment, and rosuvastatin + sildenafil treatment (N = 10 per groups). Results: Serum levels of cholesterol and glucose were significantly higher in the experimental group than in the control group (p &lt; 0.05). After theraphy no differences were found among the groups in relaxation responses to sodium nitroprusside. The relaxation responses to carbachol and EFS were significantly reduced in metabolic syndrome group to control group (p &lt; 0.05), but there were no differences between the other groups and control group. There was a significantly lower in-vitro relaxation response in the metabolic syndrome rabbits than in controls and the others (p &lt; 0.05). Conclusion: Both agents improve in-vitro relaxation responses of erectile tissue from metabolic syndrome rabbits to endothelial non-adrenergic, non-cholinergic and nitric oxide. This finding supports to the results of other clinical studies with these drugs

Laparoscopic dismembered pyeloplasty combined with port entrance flexible renoscopic lithotripsy

ABSTRACT Introduction: Ureteropelvic junction obstruction and concomitant calculus disease may coexist. We demonstrate our use of flexible renoscopy during laparoscopic pyeloplasty for caliceal stone removal. Patient and methods: A 28-year-old female patient presented with recurrent attacks of flank pain of two years duration. When noncontrast-CT and DTPA were performed, the patient was diagnosed with ureteropelvic junction stenosis and 3 stones with a total burden of 14mm in the lower pole of right kidney. After pneumoperitoneum was established in right flank position, three 10mm trocars were placed including one camera port. 5mm trocar was placed for convenience to retraction and dissection. The surgery was uneventful, with no operative complications or evidence of intra-abdominal bleeding. Results: The duration of the surgery was 110 minutes. The amount of bleeding was 30ml. On the postoperative 2nd day, the urethral catheter was removed and the patient was discharged on the fourth day postoperatively. Stent removal was done on the 3rd postoperative week and retrograde pyelogram showed normal ureter. Post-operative follow-up with ultrasound showed that hydronephrosis had regressed. Conclusions: Laparoscopic pyeloplasty and concomitant flexible renoscopy through lowermost trocar with basket extraction is a simple, attractive alternative for the simultaneous treatment of ureteropelvic junction obstruction presenting with coexisting nephrolithiasis. This method is useful and feasible, with minimal invasiveness and an early post-operative recovery

Residues of b-lactams and quinolones in tissues and milk samples. Confirmatory analysis by liquid chromatography-mass spectrometry

The aim of this work is to optimize and validate methods for the multiresidue determination of series of families of antibiotics as quinolones, penicillins and cephalosporins included in European regulation in food samples using LC-MS/MS. Different extraction techniques and clean-up applied to antibiotics in meat were compared. The quality parameters were established according with EU guideline. The developed method was applied to 49 positive raw milk samples from animal medicated with different antibiotics; the 63% of the analyzed samples were found to be compliant. __________________________________________________________________________________________

Simultaneous Determination of Acetaminophen (Paracetamol) and Ascorbic Acid in Pharmaceutical Formulations by LC Coupled to a Screen Printed Carbon Based Amperometric Detector

The assay of acetaminophen (APAP) and ascorbic acid (AA) was performed by liquid chromatography (LC) with amperometric detection at a screen printed carbon based electrode poised at +0.6 V versus Ag pseudoreference electrode. A microparticle based conventional RP-C18 and a monolithic RP-C18 column were studied comparatively for the analytes separation using a mobile phase based on 0. 1 M phosphate buffer-methanol 91: 9 (v/v) at pH 6.5. The linear calibration range for both compounds was comprised within 2 x 10(-7)-1 x 10(-4) M. Limit of detection (LOD) for APAP and AA was 2 x 10(-7) and 5 x 10(-7) M, respectively and the limit of quantification (LOQ) was 5. 10(-7)and 1 x 10(-6) M, respectively. Square wave voltammetry at a Nafion modified glassy carbon electrode was developed and applied to the determination of APAP in order to validate the results obtained by the monolithic LC method for drug formulations