The switch mechanism of the cell death mode from apoptosis to necrosis in menadione-treated human osteosarcoma cell line 143B cells

Time-dependent changes in the cell death mode from apoptosis to necrosis were studied in cultured 143B cells treated with menadione, an anti-cancerous drug, excluding a possible involvement of "secondary necrosis." The population of apoptotic cells judged by FITC-Annexin V and propidium iodide (PI) double staining reached its maximum at 6 hours after 100 microM menadione treatment followed by an abrupt decrease thereafter, while that of necrotic cells continuously increased reaching 90% at 24 hours. Electron microscopically, cells attached to the culture dish at 6 hours after the treatment consisted of two different types of cells: cells with typical apoptotic features occupying the major population and those with condensed nuclei and swollen cytoplasm. Cells attached to the culture dish at 8 hours after the treatment consisted exclusively of those with condensed nuclei and swollen cytoplasm. Mitochondria in these cells showed various structural changes: those swollen to various degrees with deposition of flocculent densities, or those with highly condensed matrix. Distinct decreases both in intracellular levels of ATP and caspase-3-like activities and remarkable elevations of intracellular levels of superoxide, which were partly suppressed by NAD(P)H oxidase inhibitors, occurred at 6 hours after the treatment. These results may suggest that distinct increases of the intracellular level of superoxide derived from plasma membrane NAD(P)H oxidase besides that from mitochondria have triggered the transition of cell death mode from apoptosis to necrosis. Transition of highly condensed mitochondria to extremely swollen ones may reflect necrotic processes in menadione-treated cells. The present study strongly suggests that time-dependent study is essential using the electron microscopic technique to analyze detailed processes in the changes of the cell death mode.     

A strategy for identifying differences in large series of metabolomic samples analyzed by GC/MS

In metabolomics, the purpose is to identify and quantify all the metabolites in a biological system. Combined gas chromatography and mass spectrometry (GC/MS) is one of the most commonly used techniques in metabolomics together with 1H NMR, and it has been shown that more than 300 compounds can be distinguished with GC/MS after deconvolution of overlapping peaks. To avoid having to deconvolute all analyzed samples prior to multivariate analysis of the data, we have developed a strategy for rapid comparison of nonprocessed MS data files. The method includes baseline correction, alignment, time window determinations, alternating regression, PLS-DA, and identification of retention time windows in the chromatograms that explain the differences between the samples. Use of alternating regression also gives interpretable loadings, which retain the information provided by m/z values that vary between the samples in each retention time window. The method has been applied to plant extracts derived from leaves of different developmental stages and plants subjected to small changes in day length. The data show that the new method can detect differences between the samples and that it gives results comparable to those obtained when deconvolution is applied prior to the multivariate analysis. We suggest that this method can be used for rapid comparison of large sets of GC/MS data, thereby applying time-consuming deconvolution only to parts of the chromatograms that contribute to explain the differences between the samples.     

Ultrastructural basis for the transition of cell death mode from apoptosis to necrosis in menadione-treated osteosarcoma 143B cells

Time-dependent ultrastructural changes of menadione-treated human osteosarcoma 143B cells were correlated with those in their stainability to Annexin V and propidium iodide (PI). Populations of both apoptotic (Annexin V(+)/PI(-)) and necrotic (Annexin V(+)/PI(+)) cells, judged by flow cytometry, began to increase at 2 h after menadione treatment. The former reached a maximum at 6 h followed by abrupt decreases thereafter, while the latter continued to increase. Electron microscopically, cells obtained at 6 h after the menadione treatment consisted of mixed populations of cells with typical apoptotic features and those with a mixture of apoptotic and necrotic features, while cells obtained at 8-24 h consisted exclusively of cells with a mixture of apoptotic and necrotic features. Thus, necrotic cells, as judged by flow cytometry, were in a transitional state of cell death mode from apoptosis to necrosis and are thus designated as 'intermediate cells'. Lack of apoptotic bodies, judged by flow cytometric analysis on sub-G1 nuclei and by electron microscopy in menadione-treated cells, suggested that the transition of cell death mode from apoptosis to necrosis occurred before the apoptotic processes were completed. Effects of N-acetylcysteine and Z-VAD-fmk on menadione-induced ultrastructural changes were also studied.     

Digital Simulation of an SCR-Driven DC Motor

The digital computer program simulating the SCR-driven dc motor is described. The program is particularly well suited to the investigation of the motor dynamics when both continuous and discontinuous conduction occur. The input signals to the system are a sequence of gate pulses and the instantaneous load torque, and the output signals are the instantaneous armature current and speed. The flowchart of the program, which is based on numerical integration, and an example of the calculated response to a change in the firing angle are given.     

Korrosionsbeständigkeit von CrNi-Stahlguß (Typ 18/9 bzw. 18/13) mit erhöhtem Siliciumgehalt in konzentrierten Salpetersäurelösungen

Corrosion resistance of chromium nickel cast steel (types 18/9 and 18/13) within increased silicon content in concentrated nitric acid solutions The corrosion resistance of CrNi cast steel, types 18/9 and 18/13, with different carbon (0.035-0.12%) and silicon (appr. 4%) contents was investigated in nitric acid (27-96%) eventually containing Cr⁶⁺ ions between 25 and 100°C. In this connection mechanical properties and structure of the above cast steels were determined, too. It has been found that in the case of 80% nitric acid solutions and of nitric acid solutions of higher or lower concentrations but containing Cr⁶⁺ ions the cast steel must have a silicon content of appr. 4% together with a carbon content as low as possible. The results of the laboratory tests have been confirmed unter industrial conditions.     

Identification of diffusive transport properties of poly(vinyl alcohol) hydrogels from reservoir test

In this paper the identification of diffusion coefficient, retardation factor and surface distribution coefficient for selected salts in poly(vinyl alcohol) hydrogels is performed. The identification of the transport parameters is based on the previously developed inverse problem technique using experimental data from the reservoir test and the solution of the diffusive transport equation with linear equilibrium sorption. The estimated values of diffusion coefficient are: for physiological fluid (6.30 ± 0.10) × 10^? 10 m²/s, for 1 M NaCl (6.42 ± 0.39) × 10^? 10 m²/s, and for 1 M KCl (7.94 ± 0.38) × 10^? 10 m²/s. The retardation factor for all tested materials and salts is equal or close to one. The average value of the effective surface distribution coefficient is equal to 0.5.     

Mathematical Modeling of Two-Stage Extraction Kinetics using the Single Drop Technique

This paper focuses on the mathematical modeling of the two-stage extraction using the single drop technique. Two stages of extraction are being considered: the drop formation step, where dimensions of the drop are highly dependent on time, and the drop travel step, during which the drops size and dimensions are assumed constant. Models for both extraction steps are derived and the combined model is proposed. Two-stage and one-stage models of extraction are compared. Errors occuring when considering only the travel stage of the single drop extraction have been calculated and their dependencies on various extraction parameters have been determined. The analysis of the combined two-stage model has proven that the travel-stage-only model generates significant errors during the determination of reaction rate constants when the drop formation time is significant in relation to the whole extraction time. Thus, the two-stage model should be used to reduce originating errors.     

The effect of dietary CLA supplementation on meat and eating quality, and the histochemical profile of the m. longissimus dorsi from stress susceptible fatteners slaughtered at heavier weights

The influence of adding 2% CLA to the morning feed of a group of 20 crossbred fatteners from 70 to 130 kg on meat quality, eating quality and dietetic value of m. longissimus dorsi was evaluated compared with a group of 20 controls. Addition of 2% CLA in feed did not influence fattening and slaughter results and also some traits of meat and eating quality. The only significant differences were observed in dry matter content, in meat flavour and L^*, b^*, and hue angle value. Meat from fatteners from the experimental group had a statistically significant higher content of CLA (P0.01) and lower content of unsaturated fatty acids especially C18: 2, C18: 1 and C20: 4, PUFA fatty acids (P0.01) and a reduction in the ratio of n-6: n-3 PUFA (P0.01). No statistically significant influence of CLA on the content of cholesterol was observed. The results of the current histochemical study showed that dietary CLA supplementation significantly increased both the number and diameter of white fibres, and correspondingly reduced the number and diameter of red fibres. The percentage and diameter of intermediate fibres was unaffected by CLA.