Dispersive micro-solid phase extraction based on two MOFs as highly effective adsorbents for analysis of nilotinib in plasma and wastewater.

BACKGROUND: Nilotinib (NIL) is a prescription medication employed in the treatment of specific types of leukemia, namely chronic myelogenous leukemia (CML). The determination of NIL levels in patients undergoing treatment for CML is of paramount importance for effective management of treatment and toxicity. Also, monitoring and controlling its level in wastewater sources could help scientists to identify potential hotspots of contamination and take appropriate measures to mitigate their impact on the environment and public health. OBJECTIVES: This study presents a D-µ-SPE technique utilizing two MOFs as adsorbents for the efficient detection of nilotinib in plasma and wastewater samples for the first time. METHODS: Two highly effective MOFs, MIL-101(Fe) and MIL-53(Al), were synthesized and applied as dispersive micro-solid phase extraction (D-µ-SPE) adsorbents for the extraction of nilotinib coupled with HPLC-UV in a short time of analysis. Experimental parameters affecting extraction efficacy such as adsorbent amount, ionic strength, pH value, adsorption-desorption time and type of elution solvent, were optimized. RESULTS: Under optimal experimental conditions, the linear dynamic was achieved in the range of 0.25-5.00 µg/mL in human plasma and 0.01-0.20 µg/mL in wastewater. The extraction recovery was in the range of 89.18-91.53% and 94.39-99.60% for nilotinib and MIL-101(Fe) and also 91.22-97.35% and 98.14-100.78% for nilotinib and MIL-53(Al) from human plasma and wastewater respectively. CONCLUSION: HPLC-UV determination of nilotinib after the D-µ-SPE method showed acceptable accuracy and precision in both plasma and wastewater. In comparison between the two adsorbents, the extraction procedure was easier and faster with MIL-53(Al) as the adsorbent.

Design of experiments approach for the development of a validated method to determine the exenatide content in poly(lactide-co-glycolide) microspheres.

Due to the lack of pharmacopeia guidelines for injectable microspheres based on poly (D, L-lactide-co-glycolide) (PLGA), an internal method validation is a critical prerequisite for quality assurance. One of the essential issues of developing peptide-based drugs loaded PLGA microspheres is the precise determination of the amount of peptide drug entrapped in the microspheres. The aim of this study is the development and optimization of a method for measuring the drug content loading of PLGA microspheres using exenatide as a model peptide drug. Exenatide-loaded PLGA microspheres were prepared by a double emulsion solvent evaporation method. The extraction method to determine exenatide content in microspheres was optimized using Design of Experiments (DoE) approach. After the initial screening of six factors, using Fractional Factorial design (FFD), four of them, including type of organic solvent, buffer/organic solvent ratio (v/v), shaking time and pH, exhibited significant effects on the response, namely the exenatide loading, and a Box-Behnken design (BBD) was subsequently applied to obtain its optimum level. The optimum level for organic solvent volume, buffer/organic solvent ratio, shaking time, and pH were 4 ml, 1, 5.6 hrs, and pH 6, respectively. The exenatide content in microspheres under these conditions was 6.4 ± 0.0 (%w/w), whereas a value of 6.1% was predicted by the derived equation. This excellent agreement between the actual and the predicted value demonstrates that the fitted model can thus be used to determine the exenatide content.

Bisphenol-A in biological samples of breast cancer mastectomy and mammoplasty patients and correlation with levels measured in urine and tissue.

Endocrine disrupting chemicals (EDCs) are organic compounds that have estrogenic activity and can interfere with the endocrine system. Bisphenol-A (BPA) is one of these compounds which possess a potential risk for breast cancer. The aim of this research was to evaluate BPA concentration in both the urine and breast adipose tissue samples of breast cancer mastectomy and mammoplasty patients and study correlations of BPA levels in breast adipose tissue with urine samples in the both groups. Urine and breast adipose tissue samples from 41 breast cancer mastectomy and 11 mammoplasty patients were taken. BPA concentrations were detected using an ELISA assay. Urinary BPA concentrations were significantly higher in cancerous patients (2.12 ± 1.48 ng/ml; P < 0.01) compared to non-cancerous (0.91 ± 0.42 ng/ml). Likewise, tissue BPA concentrations in cancerous patients (4.20 ± 2.40 ng/g tissue; P < 0.01) were significantly higher than non- cancerous (1.80 ± 1.05 ng/g tissue). Urinary BPA concentrations were positively correlated with breast adipose tissue BPA in the case group (P < 0.001, R = 0.896). We showed that BPA was present in urine and breast adipose tissue samples of the studied populations. With regard to higher BPA mean concentration in cancerous patients than non-cancerous individuals in this study, BPA might increase the risk of breast cancer incidence.

Optimization of chitosan-based polyelectrolyte nanoparticles for gene delivery, using design of experiment: in vitro and in vivo study.

Gene therapy is a novel approach for cancer treatment and investigation for suitable gene delivery systems is remarkable. Here, preparation of a polyelectrolyte complex containing polysaccharides: trimethyl chitosan (TMC) as the positive and hyaluronate (HA), dextran sulfate and alginate as the negative part was studied. The optimized nanoparticles (TMC: between 0.2 and 0.47 mg/ml, HA: 0.35 mg/ml (≈131 nm, nearly full gene loading)) were obtained via primary screening followed by the D-optimal method. In vitro cellular study on the MCF7 cell line confirmed the non-toxicity and high cellular uptake (>90%) of prepared nanoparticles. Notably, in vivo study indicated noticeable tumor uptake of nanoparticles while low accumulation in vital organs such as heart, liver and lungs. Moreover, although a qualitative variable was considered, the applied method restricted the number of runs by selecting spots from the spherical atmosphere. The prepared nanoparticles could be suggested as an efficient and safe delivery system for cancer gene delivery.

Screening for Type II L-Asparaginases: Lessons from the Genus Halomonas.

Among the two types of bacterial L-asparaginases, only type II enzymes have been used in the treatment of acute lymphoblastic leukemia owing to their higher affinity for L-asparagine. However, current screening media used for the isolation of L-asparaginase-producing microorganisms do not discriminate between the two types of L-asparaginase. During an optimization study conducted to increase L-asparaginase production by environmental Halomonas isolates, it was noticed that the pattern of L-asparaginase production in response to variations in glucose concentration varied between different isolates suggesting that they differ in their ability to produce type II L-asparaginases, an observation that was confirmed by further experiments. Bioinformatics analysis of available Halomonas whole genome sequences revealed that indeed some species of this genus possess both L-asparaginase types while others possess only type I enzymes. By comparing the growth pattern of these isolates on different media, we propose that by omitting glucose, reducing the concentration of L-asparagine and providing an alternative nitrogen source in L-asparaginase screening media it may be possible to differentiate between type I and type II activities.

Fabrication and biological evaluation of chitosan coated hyaluronic acid-docetaxel conjugate nanoparticles in CD44(+) cancer cells.

BACKGROUND: Hyaluronic acid (HA) has been used for target-specific drug delivery because of strong affinity to CD44, a marker in which overexpressed in cancer cells and cancer stem cells. Conjugation of HA to the cytotoxic agents via active targeting can improve efficacy, biodistribution, and water solubility. To be able to benefit from passive targeting as well, a nanoparticulate system by counter ion using a polycation like chitosan may lead to a perfect delivery system. METHODS: Water soluble Hyaluronic acid-Docetaxel (HA-DTX) conjugate was prepared and used to formulate chitosan-coated HA-DTX nanoparticles by polyelectrolyte complex (PEC) method and optimized using Box-Behnken design. Biological evaluation of nanoparticles was done in CD44+ cancer cells. RESULTS AND DISCUSSION: Biological evaluation of optimized formula showed IC50 of nanoparticles for 4 T1 and MCF-7 cell lines were 45.34 µM and 354.25 µM against 233.8 µM and 625.9 µM for DTX, respectively with increased cellular uptake showed by inverted confocal microscope. CONCLUSION: Chitosan-coated HA-DTX nanoparticles were more effective against CD44+ cells than free DTX. Chitosan coated hyaluronic acid-docetaxel conjugate nanoparticles fabricated and evaluated in CD44+ cancer cells.

Blood Concentrations of Cadmium and Lead in Multiple Sclerosis Patients from Iran.

Since industrial revolution heavy metals such as lead (Pb) and cadmium (Cd) have been extensively dispersed in environment which, unknown biological effects and prolong biological half-life make them as a major hazard to human health. In addition, the sharp increase in Multiple sclerosis incidence rateshas been recorded in Iran. The propose of this study was to measuring blood lead and cadmium concentration and their correlation with smoking habit in a group of 69 RRMS patients and 74 age/gender-matched healthy individuals resident in Tehran as most polluted city in Iran. All subjects were interviewed regarding age, medical history, possible chemical exposure, acute or chronic diseases, smoking and dietary habits. Blood Pb and Cd levels were measured by double beam GBC plus 932 atomic absorption spectrometer. Our result indicated a significant difference in Cd level (p = 0.006) in which, MS patients had higher blood concentration (1.82 ± 0.13 µg/L) in comparison with healthy individuals (1.47 ± 0.11 µg/L). A comparable blood Cd level to similar recent study (1.78 µg/L vs.1.82 µg/L) was observed. With respect to Pb there was no significant difference between cases and controls, however the geometric means of blood Pb concentration were considerably higher in males than in females in MS patients (57.1 ± 33.7 µg/L vs. 36.7 ± 21.9 µg/L. P = 0.02). Taking into consideration tobacco smoking, an elevated contents of each metal were observed in smoker subjects (p<0.0001). A significant correlation between cigarette smoking and risk of multiple sclerosis was shown before. Thus, high level of Cd in smokers might affect the susceptibility to multiple sclerosis and could increase the risk of disease development.

Chitosan polyplex nanoparticle vector for miR-145 expression in MCF-7: Optimization by design of experiment.

miR-145, a tumor suppressor micro RNA (miRNA), is down regulated in cancer and can be introduced as a therapeutic agent in various cancers including breast cancer. In this study, miR-145 plasmid was transfected to MCF-7 cells using chitosan polyplex nanoparticles. The vector was prepared according to an optimized fabricating method determined by response surface analysis and D-optimal design. Effects of chitosan molecular weight (Mw) and polymer amine to DNA phosphate ratio (N/P) as the variables were investigated on size, zeta potential, stability, and transfection efficiency of the polyplex nanoparticles. The results indicated that there is an interaction between effects of Mw and N/P ratio on the size of nanoparticles. Gel retardation assay demonstrated that the stability of the complexes in serum and preparation medium during storage time depends on the formulation variables. Statistical analysis affirmed that in spite of particle size, the variables of N/P ratio, time of incubation, and zeta potential affect the gene transfection. In conclusion, by selecting the perfect formulation prepared through an optimized method, it is possible to achieve a high transfection efficacy for miR-145 as an anticancer biological macromolecule.

Docetaxel Loaded PEG-PLGA Nanoparticles: Optimized Drug Loading, In-vitro Cytotoxicity and In-vivo Antitumor Effect.

In this study a 3-factor, 3-level Box-Behnken design was used to prepare optimized docetaxel (DTX) loaded pegylated poly lactide-co-glycolide (PEG-PLGA) Nanoparticles (NPs) with polymer concentration (X1), drug concentration (X2) and ratio of the organic to aqueous solvent (X3) as the independent variables and particle size (Y1), poly dispersity index (PDI) (Y2) and drug loading (Y3) as the responses. The cytotoxicity of optimized DTX loaded PEG-PLGA NPs was studied in SKOV3 tumor cell lines by standard MTT assay. The in-vivo antitumor efficacy of DTX loaded PLGA-PEG NPs was assessed in tumor bearing female BALB/c mice. The optimum level of Y1, Y2 and Y3 predicted by the model were 188 nm, 0.16 and 9% respectively with perfect agreement with the experimental data. The in-vitro release profile of optimum formulation showed a burst release of approximately 20% (w/w) followed by a sustained release profile of the loaded drug over 288 h. The DTX loaded optimized nanoparticles showed a greater cytotoxicity against SKOV3 cancer cells than free DTX. Enhanced tumor-suppression effects were achieved with DTX-loaded PEG-PLGA NPs. These results demonstrated that optimized NPs could be a potentially useful delivery system for DTX as an anticancer agent.

Synthesis and optimization of a novel polymeric micelle based on hyaluronic acid and phospholipids for delivery of paclitaxel, in vitro and in-vivo evaluation.

Novel polymeric micelles were synthesized based on hyaluronic acid (HA) and phospholipids (PEs) including 1,2-dimiristoyl phosphatidylethanolamine (DMPE) and 1,2-distearoyl phosphatidylethanolamine (DSPE). The newly developed micelles evaluated for the physicochemical properties including structural analysis by means of FTIR. Micelles were optimized for delivery of paclitaxel (PTX). The D-optimal design was applied in order to reach micelles with high entrapment efficiency (EE %) and minimum size, simultaneously. In this design the independent variables were the co-polymer type, the drug to polymer ratio and the formulation temperature, whereas the dependent variables were EE% and micelle size. The EE% of the optimized micelles was 46.8% and 59.9% for HA-DMPE and HA-DSPE micelles, respectively. The size of the optimized micelles was in the range of around 250 nm. In vitro release study of the optimized micelles showed that PTX was released from HA-DMPE and HA-DSPE micelles as long as 23 h and 34 h, respectively. Differential scanning calorimetry (DSC) studies showed a conversion of the crystalline PTX molecules into the amorphous form in the micelles. In vivo real time image analysis showed that micellar system was mostly accumulated in the liver, spleen and heart. Accelerated stability studies represented that PTX loaded micelle formulations were stable both physically and chemically at least in 6 months' time.

cis-Dichlorodiamminoplatinum (II) glyconanoparticles by drug-induced ionic gelation technique targeted to prostate cancer: preparation, optimization and in vitro characterization.

BACKGROUND: Cancer stem cells (CSC) have been proposed as the reason of cancer relapse which are characterized mainly based on CD44+ phenotype with other supplementary markers. The aim of the present study is to fabricate cis-dichlorodiamminoplatinum (II) (CDDP) loaded glyconanoparticles using hyaluronic acid (HA) which is also known as the endogenous substrate for CD44 in vivo. METHODS: For this purpose, a drug-induced ionic gelation technique has been used to prepare CDDP-incorporated nanoparticles. To optimize the fabrication technique, stirring rate, stirring time, and HA/CDDP ratio have been selected as the main factors from other factors and subjected to face-centered central composite design for optimization purposes. The optimized nanoparticles were further characterized using different complementary methods including FTIR, SEM, AFM and DSC. To evaluate the biological effectiveness of CDDP nanoparticles release study, MTS assay, tumor cell clonogenicity and sphere formation assay have been performed as well. RESULTS: Spherical CDDP nanoparticles with Z-average approx. 150nm with low PdI were prepared by adjusting the selected variables. FTIR results indicated the presence of inclusion complexes between CDDP and HA which lead to preparing nanoparticles with high entrapment efficiency and drug content of 87.4 and 43.74 percentage respectively. In vitro release study showed a sustained release of CDDP up to 4 days, and cellular studies confirmed that nanoparticles formation keeps the anticancer activity of formulated CDDP while moderate increase in cancer stem cell suppression. CONCLUSION: It seems hyaluronic acid could be successfully exploited as carrier in cancer-targeted drug delivery with a look at targeting the CSCs.

SN38 polymeric nanoparticles: in vitro cytotoxicity and in vivo antitumor efficacy in xenograft balb/c model with breast cancer versus irinotecan.

SN38 (7-ethyl-10-hydroxyl camptothecin), a potent metabolite of irinotecan, has been considered as an anticancer candidate. Its clinical development has been hampered due to its poor solubility. As a result, SN38 loaded poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs) was developed in current study to solve its poor water solubility problem while maintaining its cytotoxicity against cancer cells. PLGA NPs were prepared using modified emulsification-solvent evaporation technique and their characteristics were optimized by central composite experimental design in which average size, entrapment efficiency and drug loading were 170.5±11.87 nm, 77.35%±2.314 and 5.95%±0.087, respectively. Scanning electron microscopy and in vitro studies consisting of drug release and cytotoxicity in 4T1 breast cancer cells followed by in vivo biodistribution and blood cytotoxicity were carried out. Therapeutic efficacy of SN38-NPs was evaluated in xenograft balb/c animal with 4T1 breast cancer. The results demonstrated that the treatment with SN38-NPs was more efficacious in comparison with irinotecan. In conclusion, superior cytotoxic effect and improved in vivo antitumor efficacy of SN38-NPs versus irinotecan introduced SN38-NPs as a promising candidate for cancer treatment investigation.

Targeted poly (L-γ-glutamyl glutamine) nanoparticles of docetaxel against folate over-expressed breast cancer cells.

A novel folate (FA) conjugated poly(l-γ-glutamyl glutamine) (PGG) nanoparticle loaded with docetaxel (DTX) was prepared to take advantage of both targeted drug delivery in breast cancer and reducing the overall side effects due to the adjuvant free formulation in comparison with Taxotere(®). Nanoprecipitation method was employed to prepare nanoparticles (NPs). The chemical structure of PGG synthesized polymers and PGG-FA conjugates and polymeric nanoparticles were characterized by H NMR, FTIR spectroscopy, field emission scanning electron microscopy, and laser scanning confocal microscopy. The average size of optimized nanoparticles with the aid of Box-Behnken experimental design was 131.96 ± 5.34(nm) with polydispersity of 0.089 ± 0.019, zeta potential of -25.8 ± 2.21(mV), and entrapment efficiency of 67.83 ± 3.29(%). In vitro cytotoxicity of the designed NPs was investigated by MTT assay against three chosen cell lines of MCF7, 4T1, and A549 based on their folate receptor expression capacity and was compared with Taxotere(®). Moreover, PGG-FOL NPs were loaded with 6-coumarin for cellular uptake investigation. In order to assess the antitumor efficacy and biodistribution of targeted NPs, 4T1 murine breast tumors were established on the balb/c mice and in vivo studies were performed. The obtained results showed that the novel designed system was highly effective against tumor cells and successfully localized in the tumor site.

Zinc protoporphyrin polymeric nanoparticles: potent heme oxygenase inhibitor for cancer therapy.

PURPOSE: Oxidation therapy is an antitumor strategy in which, apoptosis or necrosis is caused by either excess delivery of reactive oxygen species (ROS) as an oxidant or anti-oxidant inhibition. Heme oxygenase (HO) is an anti-oxidant enzyme that plays an important role in cell growth and proliferation. The purpose of this study was to prepare poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs) loaded with zinc protoporphyrin (ZnPP) to deliver the HO inhibitor into tumor. METHODS: PLGA NPs were prepared using nanoprecipitation technique and their characteristics were optimized by Box-Behnken experimental design. Scanning electron microscopy and in vitro studies consisting of drug release, HO inhibitory effect, cytotoxicity and cellular uptake followed by in vivo biodistribution and blood cytotoxicity were carried out. Internalization of coumerin-6 loaded NPs by PC3 cells was visualized by confocal laser scanning microscopy beside quantitatively analysis. RESULTS: NPs average size, entrapment efficiency and drug loading were 100.12 ± 5.345 nm, 55.6% ± 2.49 and 7.98% ± 0.341 respectively. Equal HO inhibitory effect of NPs compared to free ZnPP was observed. The IC50 value of ZnPP-NPs for PC3 human prostate cancer cells was found to be 2.14 ± 0.083 µM. CONCLUSION: In conclusion, ZnPP loaded PLGA NPs could exhibit enough HO inhibitory effect against cancer cells to be considered as a promising candidate for cancer treatment investigation.

Improved brain delivery of vincristine using dextran sulfate complex solid lipid nanoparticles: optimization and in vivo evaluation.

Vincristine (VC) sulfate, a freely water-soluble cytotoxic agent was incorporated into cetyl palmitate solid lipid nanoparticles (SLNs) with the aid of dextran sodium sulfate (DS), a poly anion, using a microemulsion method. The manufacturing process was optimized using response surface methodology (Box-Behnken design). SLNs were characterized for size, zeta potential, morphology, crystallinity, and release behavior. The drug encapsulation efficiency reached up to 93% and release study revealed sustained drug release. SLN formulation showed comparable cytotoxic effect in comparison to VC sulfate solution against the MDA-MB-231 cells. The in vivo studies following injection to rat revealed higher plasma and tissue concentrations and longer drug mean residence times compared to VC solution. Using cumarin-6 as a model drug, it was shown that drug delivery to the brain was enhanced close to five times using SLNs prepared in this study compared to free cumarin-6. It can be concluded that complexes of cetyl palmitate SLNs with DS could produce high VC-loaded SLNs suitable for delivery of anticancer drugs to brain tumors.

The protective effect of albumin on bevacizumab activity and stability in PLGA nanoparticles intended for retinal and choroidal neovascularization treatments.

The rapidly growing applications of antibody-based therapeutics requires novel approaches to develop efficient drug delivery systems in which biodegradable polymeric nanoparticles are amongst the best candidates. In the present study bevacizumab loaded PLGA nanoparticles were formulated by water-in-oil-in-water emulsion method. Protein inactivation and aggregation are the major drawbacks of this technique. Therefore protective ability of various stabilizers was studied during entrapment process. Probable changes in VEGF165 binding capability of bevacizumab was assayed by ELISA which portrays the antibody's bio-efficiency. Probable breakage of bevacizumab and its secondary and tertiary structural integrity upon entrapment were analyzed by SDS-PAGE and circular dichroism spectroscopy, respectively. In vitro and ex vivo released bevacizumab from the prepared nanoparticles was also investigated. Results revealed that the protein interfacial adsorption is the foremost destabilizing factor in the double emulsion method and incorporation of appropriate concentrations of albumin could protect bevacizumab against entrapment stress. Ex vivo release results, in rabbit vitreous, indicated the ability of prepared nanoparticles in prolonged release of the active antibody. Consequently this approach was an attempt to achieve sustained release PLGA nanoparticle formulation with the aim of protecting integrity and performance of entrapped bevacizumab.

An evaluation and partial characterization of a bacteriocin produced by Lactococcus lactis subsp lactis ST1 isolated from goat milk

A bacteriocin-like inhibitory substance producing Lactococcus lactis subsp lactis strain, ST1, isolated from goat milk of Iranian origin and with broad spectrum of activity and desirable technical properties was used for evaluating some futures of bacteriocin inhibitory activity. Cell growth and bacteriocin production studies were carried out in MRS medium incubated statically under uncontrolled pH condition. The antibacterial activity presented a primary metabolite pattern and showed a rapid decrease at the stationary phase. Microaerobiosis and capnophily growth conditions resulted in higher bacteriocin production while aerobiosis showed negative effect on both cell growth and bacteriocin production. Bacteriocin production, on the other hand, was favored in MRS broth (pH; 6.5) inoculated with 0.1 ml l-1 fresh culture when incubation was carried out at 30 °C. This indicated that the conditions resulted in higher levels of growth were frequently favoring bacteriocin production by ST1 as well. Decrease in activity, at the stationary growth phase, was much pronounced in favored growth condition. Nutrient depletion, deferent effect of low pH on bacteriocin production and/or protein degradation seemed more responsible for this phenomenon. The study also provided further data on new method for bacteriocin release from the cell wall of producer. It was clearly shown that both heating and ultrasound shock for 5 min at pH 2 could increase bacteriocin activity significantly. The release was more pronounced in the presence of 0.5% Tween80.

Randomized trial of the effect of intravenous paracetamol on inflammatory biomarkers and outcome in febrile critically ill adults.

BACKGROUND AND THE PURPOSE OF THE STUDY: The febrile reaction is a complex response involving immunologic and other physiologic systems. Antipyretics are commonly used in critically ill patients with fever. We investigated the inflammatory responses following application of antipyretic therapy in febrile critically ill patients with Systemic Inflammatory Response Syndrome (SIRS). PATIENTS AND METHODS: In a prospective, randomized controlled study, critically ill patients with fever (T ≥ 38.3°C), SIRS diagnosed within 24 hours of Intensive Care Unit (ICU) admission and Acute Physiology and Chronic Health Evaluation II (APACHE II) score ≥10 were randomized into two groups. Upon appearance of fever, one group received intravenous paracetamol 650 mg every 6 hours for 10 days and other group received no treatment unless temperature reached 40°C. Body temperature, Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sepsis-related Organ Failure Assessment (SOFA) scores, length of ICU stay, ICU mortality and infectious complications were recorded. Levels of Interleukin-1 alpha (IL-1α), IL-6, IL-10, Tumour Necrosis Factor alpha (TNFα) and High-Sensitive C-Reactive Protein (HS-CRP) were assessed at baseline and 2, 6 and 24 hours after intervention. RESULTS AND DISCUSSION: During a period of 15-month screening, 20 patients met the criteria and randomized to the control or paracetamol group. Body temperature decreased significantly in the paracetamol group (p = 0.004) and control group (p = 0.001) after 24 hours, but there was no significant difference between two groups at this time point (p = 0.649). Levels of IL-6 and IL-10 decreased significantly (p = 0.025 and p = 0.047, respectively) in the paracetamol group at 24 hours but this was not of statistical significance in control group. No patterns over time in each group or differences across two groups were found for HS-CRP, TNFα, and IL-1α (p > 0.05). There were no differences regarding ICU length of stay, mortality and infectious complications between both groups. CONCLUSION: These results suggest that antipyretic therapy may not be indicated in all ICU patients. Allowing fever to take its natural course does not appear to have detrimental effects on critically ill patients with SIRS and may avoid unnecessary expenses.

Optimization of the simultaneous determination of imatinib and its major metabolite, CGP74588, in human plasma by a rapid HPLC method using D-optimal experimental design.

A simple, rapid and specific HPLC method has been developed and validated for the simultaneous determination of imatinib, a tyrosine kinase inhibitor, and its major metabolite, CGP74588, in human plasma. The optimization of the HPLC procedure involved several variables, of which the influences of each was studied. After a series of preliminary-screening experiments, the composition of the mobile phase and the pH of the added buffer solution were set as the investigated variables, while the resolution between imatinib and CGP74588 peaks, the retention time and the imatinib peak width were chosen as the dependent variables. Applying D-optimal design, the optimal chromatographic conditions for the separation were defined. The method proved to show good agreement between the experimental data and predictive values throughout the studied parameter range. The optimum assay conditions were achieved with a Chromolith™ Performance RP-8e 100 mm × 4.6 mm column and a mixture of methanol/acetonitrile/triethylamine/diammonium hydrogen phosphate (pH 6.25, 0.048 mol L(-1)) (20:20:0.1:59.9, v/v/v/v) as the mobile phase at a flow rate of 2 mL min(-1) and detection wavelength of 261 nm. The run time was less than 5 min, which is much shorter than the previously optimized methods. The optimized method was validated according to FDA guidelines to confirm specificity, linearity, accuracy and precision.

Quantification of endogenous steroids in human urine by gas chromatography mass spectrometry using a surrogate analyte approach.

Providing "real blank sample" is a problem in determination of endogenous steroids in complex matrices. A new quantification strategy is proposed in the present study, which is based on using isotope-labeled steroids instead of natural steroids for constructing calibration line. This approach is called surrogate analyte and it is shown that its accuracy is better than some of the previously described methods at low concentrations and comparable to standard addition method at medium and high concentration levels. The method was fully validated to satisfy the ICH criteria and it was applied for determination of endogenous steroids in several urine samples.