Upgrading of solid recovered fuel (SRF) by dechlorination and catalytic pyrolysis over nanocrystalline ZSM-5 zeolite

Globally increasing concern related to municipal solid waste generation is encouraging research efforts on developing alternative routes to valorize mixed refused wastes. In this way, catalytic pyrolysis is emerging as an interesting and efficient technology due to its great flexibility in terms of feedstock. In the current work, upgrading of a Solid Recovered Fuel (SRF) has been investigated by catalytic pyrolysis over nanocrystalline ZSM-5 zeolite (n-ZSM-5), paying special attention to dechlorination effects due to the high Cl content of the raw waste. Thus, pretreatment of the SRF by water washing and mild thermal processing allows for a significant reduction of the Cl concentration. Regarding the catalytic pyrolysis step, the best conditions correspond with a temperature of 400 °C in the catalyst bed and 0.50 catalyst/SRF mass ratio, which lead to ca. 30 wt% oil yield (rich in aromatic hydrocarbons) together with about 40 wt% gas yield (rich in C3-C4 olefins). Accordingly, these products could find use as raw chemicals or for the production of advanced fuels. In addition, zeolite reutilization has been tested for several cycles, denoting a progressive modification of the products distribution because of coke deposition. However, an almost total recovery of the n-ZSM-5 zeolite catalytic performance is achieved after regeneration by air calcination, affording the production of an oil fraction with a Cl content as low as 40 ppm.

Gut-Derived Uremic Toxins in CKD: An Improved Approach for the Evaluation of Serum Indoxyl Sulfate in Clinical Practice

In the past years, indoxyl sulfate has been strongly implicated in kidney disease progression and contributed to cardiovascular morbidity. Moreover, as a result of its elevated albumin affinity rate, indoxyl sulfate is not adequately cleared by extracorporeal therapies. Within this scenario, although LC-MS/MS represents the conventional approach for IS quantification, it requires dedicated equipment and expert skills and does not allow real-time analysis. In this pilot study, we implemented a fast and simple technology designed to determine serum indoxyl sulfate levels that can be integrated into clinical practice. Indoxyl sulfate was detected at the time of enrollment by Tandem MS from 25 HD patients and 20 healthy volunteers. Next, we used a derivatization reaction to transform the serum indoxyl sulfate into Indigo blue. Thanks to the spectral shift to blue, its quantity was measured by the colorimetric assay at a wavelength of 420-450 nm. The spectrophotometric analysis was able to discriminate the levels of IS between healthy subjects and HD patients corresponding to the LC-MS/MS. In addition, we found a strong linear relationship between indoxyl sulfate levels and Indigo levels between the two methods (Tandem MS and spectrophotometry). This innovative method in the assessment of gut-derived indoxyl sulfate could represent a valid tool for clinicians to monitor CKD progression and dialysis efficacy.

Extra virgin olive oil extract rich in secoiridoids induces an anti-inflammatory profile in peripheral blood mononuclear cells from obese children

Obesity represents an important public health challenge of the twenty first century reaching epidemic proportions worldwide; this is especially true for the pediatric population. In this context, bioactive compounds from foods are crucial to counteract chronic inflammation as a typical feature of obesity. In particular, extra virgin olive oil (EVOO) is one of the most important functional foods exerting, among others, an anti-inflammatory activity not only due to its major (monounsaturated fatty acids) but also to its minor (phenolics) components, as reported in the last years. However, only a limited number of studies were performed on pediatric population, and even fewer are those focusing on EVOO phenolics that investigate the correlation of the chemical characterization with the biological function. Thus, starting from our in vitro data identifying an EVOO chemical profile characterized by a high content of secoiridoids correlating with an anti-inflammatory effect, we studied the ability of an EVOO extract with the same chemical profile to retain this function ex vivo. Specifically, peripheral blood mononuclear cells (PBMCs) collected from obese children were treated with EVOO and olive oil extracts, characterized by a low polyphenol content, to study the ability of secoiridoids to dampen the inflammatory response. A reduction of pro-inflammatory CD14⁺CD16⁺ monocytes was detected by cytofluorimetric analysis when PBMCs were treated with EVOO as compared to olive oil extracts. According to this, a down modulation of CCL2 and CCL4 chemokines involved in the recruitment of inflammatory cells, was reported in the supernatants of EVOO relative to olive oil extracts treated PBMCs. Moreover, a high-throughput gene expression analysis revealed that PBMCs molecular profile from obese children is greatly modulated after the treatment with EVOO extract in terms of metabolic and inflammatory pathways. Importantly, some of the significantly modulated genes were involved in the pathways promoting the development of severe obesity. Overall, our ex vivo data demonstrated the ability of EVOO to reduce the inflammatory milieu of PBMCs from obese children both at protein and molecular levels. Of note, a good correlation between the EVOO chemical profile and the biological modulations in terms of anti-inflammatory activity was reported.

LC-MS/MS Analysis on Infusion Bags and Filled Syringes of Decitabine: New Data on Physicochemical Stability of an Unstable Molecule

Many anticancer drugs are reported to have low physicochemical stability after dilution; therefore, producers impose short times from reconstitution, dilution, and the end of administration. The precariousness of cancer patients' health in real-life experience within cancer hospitals often forces delays in the drug administration with respect to the standard treatment schedule timing, because of acute toxicities or the need to postpone a control analysis before administration. The public health costs for discarded anticancer drugs due to administration interruptions can be avoided, thanks to independent analytical studies, which integrate the producer's data reported in the technical sheet, referring to the real conditions of preparation in a sterile atmosphere under a cabin in a laboratory dedicated to handling cytotoxic drugs in controlled conditions of temperature, pressure, and particulate contamination. Decitabine is apparently an unstable molecule, whose reported stability is only 3 h at 2-8 °C when diluted, while the mother solution must be immediately used or, otherwise, discarded. This study has investigated the physicochemical stability of decitabine both in diluted infusion bags and in sterile water reconstituted syringes at 4 °C for 0, 24, 48, and 72 h. In all performed studies, the stability-indicating method involves, for the first time, the use of liquid chromatography-tandem mass spectrometry analysis. Unexpectedly, both diluted and reconstituted solutions of decitabine are more stable than previously reported data, with a 48 h-long physicochemical stability at 2-8 °C and protected from light.

MO571: Novel Insights Into Uremic Toxins in CKD: Rapid Detection of Microbiota-Derived Indoxyl Sulfate in CKD Patients

BACKGROUND AND AIMS

Emerging evidence suggest that uremic toxins are involved in the progression of chronic kidney disease (CKD). Indoxyl Sulfate (IxS) is one of the most studied since resulted as strong predictor of cardiovascular disease (CVD) and linked with the prognosis of patients with CKD. Indeed, blood levels of IxS increase during CKD stages reaching a maximum in patients with end-stage renal disease (ESRD). Additionally, hemodialysis is able to eliminate only the blood-free fraction as the IxS albumin bond hides its removal. As a result, patients on dialysis show the highest IxS levels resulting in worsening condition, enhancement of CVD-related complication. Thus, IxS rapid quantification could offers clinicians an alternative method for monitoring CKD progression and address the dialysis effectiveness. Liquid chromatography/tandem mass spectrometry (LC-MS/MS) is commonly used for IxS detection and require dedicated equipment and skills, long analysis times and costly analytical instruments. To address these issues, the development of a simple and rapid analytical method for IxS detection is needed. Here, we present a study focused on the development and validation of a rapid and simple method of IxS determination based on colorimetric array-based analysis exploitable in clinical practice for CKD patients.

METHOD

A total of 20 blood samples (10 healthy people and 10 CKD patients) were used to assess the feasibility of our colorimetric assay. IxS from serum sample was quantified at time of inclusion by LC-MS/MS. Next, from the same samples, we used a derivatization reaction for splitting the serum IxS into indigo-blue. This method enables the rapid quantification of IxS-derived indigo by a smart spectrophotometer at λ = 420–450 nm. Analyte concentration was instantly calculated from absorbance/concentration calibration curve of indigo-blue. Finally, a correlation between the two methods were carried out for the colorimetric analysis validation.

RESULTS

To accurately determine concentrations of IxS in the low µM range for practical diagnostic purposes, a wide linear calibration curve of was successfully established. The calibration curve ranged from ‘0 µM to 330 µM’ for indigo blue. The regression equation between absorbance and concentration was y = 0.0003 x + 0.0192, and the correlation coefficient (r2) was 0.9941. The feasibility was confirmed by detecting IxS in serum samples from healthy people and CKD patient. A positive correlation was observed between IxS quantified by LC-MS/MS and IxS-derived indigo quantified by spectrophotometry (P < 0 001, r = 0.088). Furthermore, the results of colorimetric analysis were compared with those obtained using LC–MS/MS, and no significant difference was found between them (Fig. 2). This result indicated that the colorimetric detection of IxS is comparable to LC–MS/MS, but it is simpler and faster for CKD monitoring in clinical practice.

CONCLUSION

The aim of our study was to develop and validate a quantitative method for the rapid estimation of serum IxS employable to monitor CKD progression in clinical setting, identify patient at risk and help further dialysis therapies aimed to lowering blood uremic toxins. Conventionally, LC-MS/MS is the most used diagnostic tool for the IxS quantification due to high sensitivity and accuracy. However, the great rigorousness analysis together with the requirement of real-time results hinders its employment in the clinical practice. Our results provide a low-cost, easy-to-operate, label-free, rapid and sensitive method for IxS determination for application in tracking IxS in blood and studying CKD progression.