Formation of 3-chloropropane-1,2-diol in systems simulating processed foods

Formation of 3-chloropropane-1,2-diol (3-MCPD) from the precursors glycerol, triolein and soy lecithin in the presence of sodium chloride was studied. The precursors were reacted with sodium chloride in an emulsion stabilised with an emulsifier under conditions which modelled the thermal treatment of foods during processing. Three sets of experiments were carried out aimed to monitor the influence of various factors (NaCl, water content and temperature) on the yield of 3-MCPD. The formation of 3-MCPD strongly depended on the concentration of NaCl and reached a maximum level at about 4–7% NaCl. The highest amount of 3-MCPD was formed in media containing approximately 13–17% water. The amount of 3-MCPD increased with increasing temperature over the range 100–230 °C and reached its highest value at 230 °C. The production of 3-MCPD was also followed in models very closely related to selected foods which had been shown to have a high potential to yield 3-MCPD during processing (salami, beefburgers, processed cheese, biscuits, crackers, doughnuts). The highest levels of 3-MCPD were formed in models simulating salami as they had the highest content of both fat and salt of all the samples. The lowest amount of 3-MCPD was formed in the models simulating biscuits and crackers as they had a low salt content and, at the same time, their water content was below the optimum level.     

Biogenic amines and polyamines in liver,kidney and spleen of roe deer and European brown hare

Cadaverine (CAD), histamine (HIS), tyramine (TYR) and the polyamines putrescine (PUT), spermidine (SPD) and spermine (SPM) were determined in liver, kidney and spleen of hunted roe deer (n = 39) and European brown hare (n = 20) 3 and 6 h post mortem, respectively. Median concentrations (mg/kg fresh weight) of CAD and TYR were <5 mg/kg for organs of both species, whereas median HIS concentrations were higher in spleen (14.6 and 11.6 mg/kg for hare and roe deer, respectively) and lowest in liver. Maximum PUT concentration was 72.9 mg/kg, but median values were ≤7.8 mg/kg. Mean SPD concentrations were 8.5, 10.7 and 42.9 mg/kg for liver, kidney and spleen of roe deer, and 37.2, 24.4 and 52.0 mg/kg for hare. Mean SPM concentrations were higher (94.6, 79.9, 102.2 and 111.2, 82.8, 91.1 mg/kg, respectively). SPM concentrations in the organs of the male roe deer were significantly higher than in those of females. SPM:SPD ratios (weight base) were in the order of 2:1 for spleen, and higher for liver and kidney. SPM and SPD were correlated significantly (r = 0.42–0.47). Although variations of polyamine concentrations are partially associated with species, organ, age and gender, the relative contribution of individual factors deserves further study.     

In vivo visualization of cells labeled with superparamagnetic iron oxides by a sub-millisecond gradient echo sequence

Object

In vivo magnetic resonance imaging (MRI) of iron-labeled pancreatic islets (PIs) transplanted into the liver is still challenging in humans. The aim of this study was to develop and evaluate a double contrast method for the detection of PIs labeled with superparamagnetic iron oxide (SPIO) nanoparticles.

Materials and methods

A double-echo three-dimensional (3D) spoiled gradient echo sequence was adapted to yield a sub-millisecond first echo time using variable echo times and highly asymmetric Cartesian readout. Positive contrast was achieved by conventional and relative image subtraction. Experiments for cell detection efficiency were performed in vitro on gelatin phantoms, in vivo on a Lewis rat and on a patient 6 months after PI transplantation.

Results

It was demonstrated that the proposed method can be used for the detection of transplanted PIs with positive contrast in vitro and in vivo. For all experiments, relative subtraction yielded comparable and in some cases better contrast than conventional subtraction. For the first time, positive contrast imaging of transplanted human PIs was performed in vivo in patients.

Conclusion

The proposed method allows 3D data acquisition within a single breath-hold and yields enhanced contrast-to-noise ratios of transplanted SPIO labeled pancreatic islets relative to negative contrast images, therefore providing improved identification.     

In situ polymerized polyaniline films: The top and the bottom

Polyaniline (PANI) films of submicrometer thickness were deposited in situ during the polymerization of aniline on polystyrene support. Aqueous poly(N-vinylpyrrolidone) solution was subsequently evaporated on the top of PANI films. During peeling off, the PANI film was transferred to a poly(N-vinylpyrrolidone) film. Both sides of the PANI film, the top surface of the film deposited on polystyrene, and the bottom surface originally in contact with a polystyrene dish, became subsequently available for the analysis by Raman and X-ray photoelectron spectroscopies. The molecular structures of both surfaces in protonated state were different, the top side corresponded to protonated emeraldine, while the bottom side to partly deprotonated cross-linked structure containing phenazine-like constitutional units. This result supports the concept of hydrophobic phenazine-like oligomers that are adsorbed at immersed surfaces during the oxidation of aniline, and PANI chains that grow from them, thus creating a brush-like PANI morphology.     

Are Changes in the Percentage of Specific Leukocyte Subpopulations Associated with Endogenous DNA Damage Levels in Testicular Cancer Patients?

Chemoresistance of germ cell tumors (GCTs) represents an intensively studied property of GCTs that is the result of a complicated multifactorial process. One of the driving factors in this process is the tumor microenvironment (TME). Intensive crosstalk between the DNA damage/DNA repair pathways and the TME has already been reported. This study aimed at evaluating the interplay between the immune TME and endogenous DNA damage levels in GCT patients. A cocultivation system consisting of peripheral blood mononuclear cells (PBMCs) from healthy donors and GCT cell lines was used in an in vitro study. The patient cohort included 74 chemotherapy-naïve GCT patients. Endogenous DNA damage levels were measured by comet assay. Immunophenotyping of leukocyte subpopulations was performed using flow cytometry. Statistical analysis included data assessing immunophenotypes, DNA damage levels and clinicopathological characteristics of enrolled patients. The DNA damage level in PBMCs cocultivated with cisplatin (CDDP)-resistant GCT cell lines was significantly higher than in PBMCs cocultivated with their sensitive counterparts. In GCT patients, endogenous DNA damage levels above the cutoff value were independently associated with increased percentages of natural killer cells, CD16-positive dendritic cells and regulatory T cells. The crosstalk between the endogenous DNA damage level and specific changes in the immune TME reflected in the blood of GCT patients was revealed. The obtained data contribute to a deeper understanding of ongoing interactions in the TME of GCTs.