Meropenem and ciprofloxacin in complicated gastric surgery for cancer patients: A simple SPE-UHPLC-PDA method for their determination in human plasma.

A simple and rapid ultra-high-performance liquid chromatographic (UHPLC) for the simultaneous determination of meropenem and ciprofloxacin in human plasma was developed and validated. All of the analytes were separated in <5 min. A solid-phase extraction method was applied from sample preparation. Analytical separation was performed on a Poroshell SB C18 column (50 × 2.1 mm, 2.7 µm particle size) with photodiode array (PDA) detection. Meropenem and ciprofloxacin were determined at wavelengths of 300 and 277 nm, respectively. The mobile phase was a mixture of acetonitrile-10 mm ammonium acetate-methanol in gradient elution. The method has been validated for both drugs in gastric surgery for cancer patients. The method showed good linearity with correlation coefficients, r2  = 0.994 for the two drugs, as well as high precision (RSD < 10.5% in each case); accuracy ranged from -5.8 to +6.0%. The limit of quantitation of the two drugs was established at 0.02 and 0.01 µg/mL, respectively. Meropenem, ciprofloxacin and the internal standard were extracted from human plasma with a mean recovery ranging from 92.5 to 98.6%. The method was applied to quantify the drugs dosage in complicated gastric surgery patients.

Is right colectomy a complete learning procedure for a robotic surgical program?

This study analyses the utility of right colectomy as a learning procedure at the beginning of a robotic surgical program. The hypothesis is that right colectomy contains all the technical steps necessary to acquire basic abilities in robotics surgery. The first 23 consecutive robotic right colectomy performed at the beginning of a robotic program were analysed. All surgical times were recorded in the operating room and second checked on a dedicated video-database. Specific robotic times were analysed using CUSUM method to evaluate the learning curve. CUSUM-derived learning phases were compared. Fourteen males and nine females with a mean age of 68.7 (46-84) underwent robotic right colectomy. The mean overall time was 265.3 min (180-320 min), docking time was 7 min (5-12 min), console time was 205.9 min (145-260 min), and anastomotic time was 43.6 (25-60 min). CUSUM analyses identified two learning phases: "starting phase" and "consolidation phase". Interphase comparison confirmed the significant (p < 0.05) differences between the two phases. Robotic technology facilitates the training process in minimally invasive colorectal surgery. At the beginning of the learning curve, right colectomy could represent a complete procedure to be proficient in robotic colorectal surgery.

Meropenem, levofloxacin and linezolid in human plasma of critical care patients: A fast semi-automated micro-extraction by packed sorbent UHPLC-PDA method for their simultaneous determination.

An ultra high-performance liquid chromatographic (UHPLC) method with PDA detection was developed and validated for the simultaneous quantification of meropenem, linezolid, and levofloxacin in human plasma and applied in human plasma of critical care patients. A semi-automated microextraction by packed sorbent (MEPS) for sample preparation was used. All parameters in the extraction step (pH, sample volume, sample dilution and number of aspiration - ejection cycles) and in the desorption step (percentage of acetonitrile in the solvent of elution and number of aspirations of elution solvent through the device) were statistically significant when the recovery was used as response. The method showed good linearity with correlation coefficients, r2>0.9991 for the three drugs, as well as high precision (RSD%<10.83% in each case). Accuracy ranged from -7.8% to +6.7%. The limit of quantification of the three drugs was established at 0.01µg/mL for linezolid and levofloxacin and 0.02µg/mL for meropenem. Linezolid, meropenem, levofloxacin and the internal standard were extracted from human plasma with a mean recovery ranged from 92.4% to 97.4%. During validation, the concentration of meropenem, linezolid and levofloxacin was found to be stable after 3 freeze-thaw cycles and for at least 24h after extraction. This method will be subsequently used to quantify the drugs in patients to establish if the dosage regimen given is sufficient to eradicate the infection at the target site.

Development of a dried blood spot HPLC-PDA method for the analysis of linezolid and ciprofloxacin in hospital-acquired pneumonia patients.

This study developed a high performance liquid chromatography (HPLC) method involving dried blood spotting (DBS) as a sampling method for the therapeutic drug monitoring of antimicrobial combination therapy with linezolid and ciprofloxacin. DBS for standards, quality control samples, and patient samples was excised and then extracted using a mixture of methanol/water/formic acid 80:20:0.1 (v/v/v), respectively. Linezolid (LZD) and ciprofloxacin (CPR) were measured by HPLC using a Kinetex EVO C18 (100 × 4.6 mm I.D. 2.6 µm particle size). Mobile phase consisted of 10 mM ammonium acetate (A) and a mixture of acetonitrile and methanol (B), both containing 0.1% triethylamine, in gradient elution. Detection was carried out at 251 nm for linezolid (LZD) and 277 for ciprofloxacin (CPR). Ulifloxacin was used as an internal standard. The internal standard, LZD, and CPR were eluted in 7.90, 7.18, and 8.89 min, respectively. Total run-time was 20 min. Calibration curves were constructed in the range of 0.05-30 µg/mL for LZD and 0.02-10 µg/mL for CPR, respectively. The intra- and inter-day precision (RSD values) did not exceed 9.43%, the intra- and inter-day accuracy (accuracy %) ranged between 96.2 and 106.2%. Haematocrit (Hct) effects were investigated to obtain a linear correlation between haematocrit values and volume of blood. Copyright © 2017 John Wiley & Sons, Ltd.

Development and validation of a fast micro-extraction by packed sorbent UHPLC-PDA method for the simultaneous determination of linezolid and ciprofloxacin in human plasma from patients with hospital-acquired pneumonia.

An ultra high-performance liquid chromatographic (UHPLC) method with PDA detection was developed and validated for the simultaneous quantification of linezolid and ciprofloxacin in human plasma and applied in hospital acquired pneumonia patients (HAP). The method uses a semi-automated microextraction by packed sorbent for sample preparation. All parameters in the extraction step (pH, sample volume, sample dilution and number of aspiration - ejection cycles) and in the desorption step (percentage of acetonitrile in the solvent of elution and number of aspirations of elution solvent through the device) were statistically significant when the recovery was used as response. The method showed good linearity with correlation coefficients, r2>0.9995 for the two drugs, as well as high precision (RSD%<9.77% in each case), accuracy ranged from -6.2% to +8.2. The limit of quantification of the two drugs was established at 0.01 and 0.02µg/mL for ciprofloxacin and linezolid, respectively. Linezolid, ciprofloxacin and internal standard were extracted from human plasma with a mean recovery ranging from 92.4% to 97.4%. During validation, the concentrations of linezolid and ciprofloxacin were found to be stable after 3 freeze-thaw cycles and for at least 24h after extraction. This method will subsequently be used to quantify the drugs dosage in patients with HAP to establish if the dosage regimen given is sufficient to eradicate the infection at the target site.

Mutual regulation of TGF-ß1, TßRII and ErbB receptors expression in human thyroid carcinomas.

The role of EGF and TGF-ß1 in thyroid cancer is still not clearly defined. TGF-ß1 inhibited the cellular growth and migration of follicular (FTC-133) and papillary (B-CPAP) thyroid carcinoma cell lines. Co-treatments of TGF-ß1 and EGF inhibited proliferation in both cell lines, but displayed opposite effect on their migratory capability, leading to inhibition in B-CPAP and promotion in FTC-133 cells, by a MAPK-dependent mechanism. TGF-ß1, TßRII and EGFR expressions were evaluated in benign and malignant thyroid tumors. Both positivity (51.7% and 60.0% and 80.0% in FA and PTC and FTC) and overexpression (60.0%, 77.7% and 75.0% in FA, PTC and FTC) of EGFR mRNA correlates with the aggressive tumor behavior. The moderate overexpression of TGF-ß1 and TßRII mRNA in PTC tissues (61.5% and 62.5%, respectively), counteracted their high overexpression in FTC tissues (100% and 100%, respectively), while EGFR overexpression was similar in both carcinomas. Papillary carcinomas were positive to E-cadherin expression, while the follicular carcinomas lose E-cadherin staining. Our findings of TGF-ß1/TßRII and EGFR overexpressions together with a loss of E-cadherin observed in human follicular thyroid carcinomas, and of increased migration ability MAPK-dependent after EGF/TGF-ß1 treatments in the follicular thyroid carcinoma cell line, reinforced the hypothesis of a cross-talk between EGF and TGF-ß1 systems in follicular thyroid carcinomas phenotype.

PRDX1 and PRDX6 are repressed in papillary thyroid carcinomas via BRAF V600E-dependent and -independent mechanisms.

Many clinical studies highlight the dichotomous role of PRDXs in human cancers, where they can exhibit strong tumor-suppressive or tumor-promoting functions. Recent evidence suggests that lower expression of PRDXs correlates with cancer progression in colorectal cancer (CRC) or in esophageal squamous carcinoma. In the thyroid, increased levels of PRDX1 has been described in follicular adenomas and carcinomas, as well as in thyroiditis, while reduced levels of PRDX6 has been found in follicular adenomas. We studied the expression of PRDX1 and PRDX6, in a series of thyroid tissue samples, covering different thyroid diseases, including 13 papillary thyroid carcinomas (PTCs). Our results show that PRDX1 and PRDX6 are significantly reduced in all PTCs compared to normal tissues, to non-neoplastic tissue (MNG) or follicular neoplasms. This reduction is strongly evident in PTCs harboring BRAF V600E (31% of our cases). Using TPC-1 and BCPAP and FRTL-5 cell lines, we demonstrate for the first time that the presence of BRAF V600E is responsible of the hypoexpression of PRDX1 and PRDX6 both at mRNA and protein levels. Finally, independently of BRAF status, we observe an interesting correlation between the tumor size, the presence of lymph node metastasis and the lowest PRDX1 and PRDX6 levels. Therefore, these data indicate that PRDX1 and PRDX6 expression not only may play a key role in papillary thyroid carcinogenesis via a BRAF V600E-dependent mechanism, but their determination could be considered as potential tumor marker for indicating tumor progression in PTCs, independently of BRAF status.