Influence of oxidative injury and monitoring of blood plasma by DSC on breast cancer patients

Damage caused by oxidative stress is involved in many types of diseases, including breast cancer. Our aim was to detect the oxidative stress parameters and blood plasma changes with differential scanning calorimetry (DSC) in breast cancer patients. The study included 40 adult breast cancer women who were grouped according to tumor diameter, regional lymph node metastases, proliferative activity, receptor status and postoperative chemotherapy. To monitor oxidative stress, malondialdehyde, oxygen free radicals (OFRs), activity of myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase (CAT) were measured. Denaturation of plasma components was detected in Setaram Micro DSC-II calorimeter. The total production of OFRs, the MPO activity and lipidperoxidation were significantly increased in each breast cancer patients considering the tumor size, the metastatic lymph nodes, the proliferation activity and receptor status compared with healthy controls (p < 0.05). These pro-oxidants were slightly elevated without chemotherapy, but their values were increased significantly in chemotherapy-receiving group. The activity of SOD and CAT was significantly decreased in all groups, and in regard to the chemotherapy, they were changed significantly parallel to the severity of disease. Regarding to both the increased tumor diameter and the increased number of affected lymph nodes, DSC measurements showed a strong relationship between the maximum excess heat capacity (C_pmax) of the blood plasma and the severity of disease. The study demonstrated that oxidative stress is implicated in breast carcinoma and chemotherapy aggravates these changes which confirmed the plasma DSC measurements also.     

Toxic and essential metals determination in commercial seafood: Paracentrotus lividus by ICP-MS

Toxic and essential metals content was determined by inductively coupled plasma mass spectrometry in commercial sea urchins samples from the Mediterranean Sea and Pacific Ocean. Results show that Chilean samples have the highest values of Cd, As, Ni, Cr and V; Spanish samples have the maximum Hg content while Sicilian samples have the lowest content of toxic metals. The toxic metal traces were compared with the limits of European Community (EC) No. 1881/2006 for bivalve molluscs. All samples exceed Pb and Cd limit levels; regarding Hg levels, only Sicilian and Sardinian samples have Hg content below the EC limits. The dietary intake of toxic and essential elements was evaluated for an adult. Furthermore, our study highlights a correlation between the toxic elements content and the marine environmental conditions of the places of origin even though only the generic FAO fishing area is specified.     

Chalk it up to experience: using chalkboard paint to create mathematical manipulatives

In this article, we give two examples of creating portable chalkboards using chalkboard paint for students to use during cooperative learning. This provides a creative method for professors to facilitate active learning in the undergraduate mathematics classroom.     

Cubic Bridgeless Graphs and Braces

There are many long-standing open problems on cubic bridgeless graphs, for instance, Jaeger’s directed cycle double cover conjecture. On the other hand, many structural properties of braces have been recently discovered. In this work, we bijectively map the cubic bridgeless graphs to braces which we call the hexagon graphs, and explore the structure of hexagon graphs. We show that hexagon graphs are braces that can be generated from the ladder on 8 vertices using two types of McCuaig’s augmentations. In addition, we present a reformulation of Jaeger’s directed cycle double cover conjecture in the class of hexagon graphs.     

The swap graph of the finite soluble groups

A graph is reflexive if the second largest eigenvalue of its adjacency matrix is less than or equal to 2. In this paper, we characterize trees whose line graphs are reflexive. It turns out that these trees can be of arbitrary order—they can have either a unique vertex of arbitrary degree or pendant paths of arbitrary lengths, or both. Since the reflexive line graphs are Salem graphs, we also relate some of our results to the Salem (graph) numbers.     

The influence of a beta-electron withdrawing substituent in aldol reactions of methylketone boron enolates

We wish to describe here that good levels of substrate-based, 1,5-syn-stereocontrol could be achieved in the boron-mediated aldol reactions of beta-trichloromethyl methylketones with achiral aldehydes, independent of the nature of the beta-alkoxy protecting group.     

Catalytic oxidation of imines based on methyltrioxorhenium/urea hydrogen peroxide: a mild and easy chemo- and regioselective entry to nitrones

[reaction: see text] The first successful catalytic oxidation procedure for the chemoselective conversion of imines to nitrones is reported. The reaction is general, high yielding, and user and environmentally friendly, and furnishes a solution to the yet unanswered issue of regioselective access to nitrones by oxidation of nitrogen derivatives.     

Simultaneous detection of L-glutamate and nitric oxide from adherently growing cells at known distance using disk shaped dual electrodes

An ex vivo system for simultaneous detection of nitric oxide (NO) and L-glutamate using integrated dual 250 microm platinum disk electrodes modified individually with suitable sensing chemistries has been developed. One of the sensors was coated with an electrocatalytic layer of Ni tetrasulfonate phthalocyanine tetrasodium salt (Ni-TSPc) covered by second layer of Nafion, which stabilises on the one hand the primary oxidation product NO(+) and prevents interferences from negatively charged compounds such as NO(2)(-). For glutamate determination, the second electrode was modified with a crosslinked redox hydrogel consisting of Os complex modified poly(vinylimidazol), glutamate oxidase and peroxidase. A manual x-y-z micromanipulator on top of an inverted optical microscope was used to position the dual electrode sensor at a defined distance of 5 microm from a cell population under visual control. C6 glioma cells were stimulated simultaneously with bradykinin or VEGF to release NO while KCl was used to invoke glutamate release. For evaluation of the glutamate sensors, in some experiments HN10 cells were used. To investigate the sensitivity and reliability of the system, several drugs were applied to the cells, e.g. Ca(2+)-channel inhibitors for testing Ca(2+)-dependence of the release of NO and glutamate, rotenone for inducing oxidative stress and glutamate antagonists for analysing glutamate release. With these drugs the NO and glutamate release was modulated in a similar way then expected from previously described systems or even in-vivo measurements. We therefore conclude that our system is suitable to analyse stress-induced mechanisms in cell lines.