SHE Cell Transformation Assay as a Predictive System for Carcinogenicity of PAH and Non-Genotoxic Carcinogens

The Syrian hamster embryo (SHE) cell transformation assay is an in vitro method for the detection of genotoxic and non-genotoxic carcinogens. Its reliability as a multistage carcinogen screening method was demonstrated by several authors who showed that cells derived from transformed colonies were capable of tumour formation when inoculated in a suitable host animal. The SHE assay offers the advantage of using normal diploïd cells with metabolizing capacities and low spontaneous transformation frequency. Epithelial cultures can be selected from the mixed cellular suspension obtained from the Syrian hamster embryos in order to develop an in vitro model for the detection of carcinogens inducing carcinomas.

Polycyclic aromatic hydrocarbons, such as BaP and DMBA were studied in depth for their cell transforming potency. The synergistic effects of PAH and tumor promoters can be demonstrated by using a sequential treatment consisting in an initiation-promotion scheme¹. This protocol also revealed interacting effects between non-genotoxic carcinogens².     

Investigations of Emission Control Systems for Gasoline Direct Injection Engines with a Focus on Removal of Particulate Emissions

The removal of particulate emissions from gasoline injection engines is a new challenge within the exhaust aftertreatment system that will arise with the introduction of limits for particle number emitted by gasoline engines. Besides a possible adjustment of the engine management to lower the particulate emissions, catalyzed gasoline particulate filters (GPF) are conceivable as efficient pollution control devices. As an advantage, these catalyzed filters in addition could be able to support the conversion of all other regulated pollutants. Therefore, an emission study was carried out with systems consisting of a three-way catalyst and a catalyzed GPF and the impact of a dedicated washcoat on the filtration efficiency of the filter was analyzed. The conversion performance of the gasoline particulate filters was examined with regard to carbon monoxide, hydrocarbons and nitrous oxides emissions. Furthermore, the influence of the additional converter on fuel consumption and CO₂ emissions over different driving cycles will be discussed. In a detailed exhaust system study a correlation between the distance of engine-outlet to GPF-inlet and the filtration efficiency of the system was observed.     

Gastric electrical stimulation has an immediate antiemetic effect in patients with gastroparesis

BACKGROUND: Electrical stimulation has been successfully employed to treat diseases involving electro-pathology in the heart, skeletal muscles, and the brain, but not in the GI tract. AIM: This study examined the clinical feasibility and efficacy of GES in treating patients with severe gastroparesis. METHODS: Nausea, vomiting, GEA, and liquid and solid gastric emptying were monitored in eleven patients with refractory gastroparesis at baseline and after one week of continuous electrical stimulation administered at 12 cycles/min. Eight patients were subsequently implanted with permanent stimulation devices. Follow-up studies were conducted after 1, 3, 6, and 12 mo. of stimulation. RESULTS: After one week of stimulation, patients' quantified symptoms of nausea and vomiting decreased significantly, and liquid emptying and GEA improved. This improvement was maintained over time in the patients who continued to receive stimulation. Emptying of solids showed progressive improvement that became significant after 3 mo. The three patients who did not receive stimulation after the trial period showed significantly higher symptoms at 12 mo. CONCLUSION: This paper demonstrates that GES at a frequency of 12 cycles/min has an immediate antiemetic effect, followed by an improvement in disordered gastric emptying.     

Continuous-flow pI-based sorting of proteins and peptides in a microfluidic chip using diffusion potential

Efficient sample preparation tools are the key to measuring molecular signals in a complex biological system. A novel continuous-flow isoelectric point (pI)-based sorting technique has been developed for proteins and peptides in a microfluidic chip format. It can sort biomolecules at a relatively high flow rate of up to 10 microL/min and does not require carrier ampholytes, which can create molecular backgrounds for subsequent analysis. Furthermore, the electrophoretic field required to run the pI-based sorting is generated by the diffusion of buffer ions in situ, at the liquid junction between two laminar flows within the microfluidic channel. Utilizing the diffusion potential in combination with a pH difference between the buffers, we demonstrated a separation of binary mixtures of pI markers and proteins without applying any external field. The sorting resolution and its efficiency are sufficiently high for sample preparation and could be further improved by optimizing buffers or with an additional transverse electric field. Once fully developed, it can potentially be a pI-based sample fractionation tool for proteomic analysis of complex biomolecule samples.     

Effect of organic co-contaminants on technetium and rhenium speciation and solubility under reducing conditions

The chemical and biogeochemical reduction of pertechnetate (TcO4-) and perrhenate (ReO4-) have been compared alongside complexation of the reduced species by three anthropogenic ligands relevant to nuclear waste (ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), and isosaccharinic acid (ISA)). An HPLC size-exclusion column coupled to ICP-MS was used to separate the species and quantify Tc and Re. During method development, ReO4- showed recalcitrance to direct chemical reduction by Sn(ll) under conditions that readily reduced TcO4- and resulted in Tc(IV)-organic complexes. In microcosm experiments of a silty loam soil containing Tc04-, ReO4-, and ISA (3.0 mM), EDTA (0.17 mM), or NTA (2.4 mM), anoxia developed to iron-reducing conditions during the 42 day experimental period. The majority of the TcO4- was reduced to particle-reactive Tc(IV) and removed from solution during nitrate reduction, but there was no chromatographic evidence of Tc(IV)-organic complexes in the porewater. Overall, the excess organic complexants added did not cause a measurable difference in the solubility of Tc(IV) over the control experiments in this organic-rich (12% organic carbon) soil. ReO4- did not undergo reduction, as shown by the constant porewater concentration and the chromatographic data, and thus Re does notfunction as an analogue forTc under environmental nitrate- and iron-reducing conditions.     

Modifiable variables affecting interdialytic weight gain include dialysis time,frequency, and dialysate sodium

Interdialytic weight gain (IDWG) is associated with hypertension, left ventricular hypertrophy, and all‐cause mortality. Dialysate sodium concentration may cause diffusion gradients with plasma sodium and influence subsequent IDWG. Dialysis time and frequency may also influence the outcomes of this Na⁺ gradient; these have been overlooked. Our objective was to identify modifiable factors influencing IDWG. We performed a retrospective multivariable regression analyses of data from 86 home hemodialysis patients treated by hemodialysis modalities differing in frequency and session duration to determine factors involved that predict IDWG. Age, diabetic status, and residual renal function did not correlate with IDWG in the univariable analysis. However, using a combination of backwards selection and Akaike information criterion to build our model, we created an equation that predicted IDWG on the basis of serum albumin, age, patient sex, dialysis frequency, and the diffusive balance of sodium, represented by the product of the duration of dialysis and the patient plasma to dialysate Na⁺ gradient. This equation was internally validated using bootstrapping, and externally validated in a temporally distinct patient population. We have created an equation to predict IDWG on the basis of independent factors readily available before a dialysis session. The modifiable factors include dialysis time and frequency, and dialysate sodium. Patient sex, age, and serum albumin are also correlated with IDWG. Further work is required to establish how improvements in IDWG influence cardiovascular and other clinical outcomes.     

Characterization of Three Types of Semtex (H, 1A,and 10)

Solid phase microextraction and solvent extraction were used with GC/MS to determine the vapor and compositional profile of three samples of Semtex (1A, H, and 10). Semtex is reported to contain PETN and/or RDX, along with plasticizers, binding materials, and fuel oil components. In an effort to differentiate and compare these three variations of Semtex, this report summarizes the headspace and solvent extraction results for each material. Components that can be used to differentiate varieties of Semtex were identified and all three Semtex profiles were distinguished.     

Using proton nuclear magnetic resonance as a rapid response research tool for methyl ester characterization in biodiesel

Reliable and rapid analysis remains a high priority for quality control in biodiesel production. Quantifying biodiesel with alternative analytical tools such as proton nuclear magnetic resonance (¹H NMR) can provide total methyl esters distributions without significant sample pretreatment. Using unique spectra of individual methyl esters, we investigate the feasibility of using ¹H NMR spectroscopy to identify and quantify relative and absolute concentrations of methyl esters in a biodiesel.     

Functional Properties of Soy Protein Isolates Produced from Ultrasonicated Defatted Soy Flakes

This study aimed to determine the effect of pretreating defatted soy flakes with ultrasound on soy protein isolate (SPI) yield and functionality. Defatted soy flakes dispersed into water (16%, w/w) were sonicated for 30, 60 and 120 s at ultrasonic amplitudes of 21 and 84 μm_pp (peak to peak amplitude in μm), representing low and high power, respectively. The power densities were 0.30 and 2.56 W mL⁻¹, respectively. The SPI yield increased by 13 and 34%, after sonication for 120 s at low and high power, respectively. The sonication of defatted soy flakes for 120 s at the higher power level improved the SPI solubility by 34% at pH 7.0, while decreasing emulsification and foaming capacities by 12 and 26%, respectively, when compared to control SPI. Rheological behavior of the SPI was also modified with significant loss in consistency coefficient due to sonication. Some of these results could be explained by the loss of the protein native state with increased sonication time and power.