Effect of raw winged bean [Psophocarpus tetragonolobus (L.) DC] tuber lectin on gastrointestinal tract of growing rats

The fraction containing high hemagglutinating activity was prepared from raw winged bean tubers and orally administered to growing rats. The food intake and body weights of these rats decreased as the level of lectin increased and significant lectin activity was detected in the faeces extracted from these rats which is anti-genically similar to the native lectin preparation. Microscopic examination has revealed morphological changes in the intestinal epithelial cells. The binding action of the lectin to the mucosal epithelia of the gastrointestinal tract is indicative of the deleterious effects caused by the winged bean tuber lectin.     

Detection of Tissue Factor Antigen and Coagulation Activity in Coronary Artery Thrombi Isolated from Patients with ST-Segment Elevation Acute Myocardial Infarction

Introduction

Although ruptured atherosclerotic plaques have been extensively analyzed, the composition of thrombi causing arterial occlusion in patients with ST-segment elevation acute myocardial infarction has been less thoroughly investigated. We sought to investigate whether coagulant active tissue factor can be retrieved in thrombi of patients with STEMI undergoing primary percutaneous coronary intervention.

Methods

Nineteen patients with ST-segment elevation acute myocardial infarction referred for primary percutaneous coronary intervention were enrolled in this study. Coronary thrombi aspirated from coronary arteries were routinely processed for paraffin embedding and histological evaluation (4 patients) or immediately snap frozen for evaluation of tissue factor activity using a modified aPTT test (15 patients). Immunoprecipitation followed by immunoblotting was also performed in 12 patients.

Results

Thrombi aspirated from coronary arteries showed large and irregular areas of tissue factor staining within platelet aggregates, and in close contact with inflammatory cells. Some platelet aggregates stained positive for tissue factor, whereas others did not. Monocytes consistently stained strongly for tissue factor, neutrophils had a more variable and irregular tissue factor staining, and red blood cells did not demonstrate staining for tissue factor. Median clotting time of plasma samples containing homogenized thrombi incubated with a monoclonal antibody that specifically inhibits tissue factor-mediated coagulation activity (mAb 5G9) were significantly longer than their respective controls (88.9 seconds versus 76.5 seconds, respectively; p<0.001). Tissue factor was also identified by immunoprecipitation in 10 patients, with significant variability among band intensities.

Conclusions

Active tissue factor is present in coronary artery thrombi of patients with ST-segment elevation acute myocardial infarction, suggesting that it contributes to activate the coagulation cascade ensuing in coronary thrombosis.     

Rotenone-induced oxidative stress and apoptosis in human liver HepG2 cells

Rotenone, a commonly used pesticide, is well documented to induce selective degeneration in dopaminergic neurons and motor dysfunction. Such rotenone-induced neurodegenration has been primarily suggested through mitochondria-mediated apoptosis and reactive oxygen species (ROS) generation. But the status of rotenone induced changes in liver, the major metabolic site is poorly investigated. Thus, the present investigation was aimed to study the oxidative stress-induced cytotoxicity and apoptotic cell death in human liver cells-HepG2 receiving experimental exposure of rotenone (12.5–250 μM) for 24 h. Rotenone depicted a dose-dependent cytotoxic response in HepG2 cells. These cytotoxic responses were in concurrence with the markers associated with oxidative stress such as an increase in ROS generation and lipid peroxidation as well as a decrease in the glutathione, catalase, and superoxide dismutase levels. The decrease in mitochondrial membrane potential also confirms the impaired mitochondrial activity. The events of cytotoxicity and oxidative stress were found to be associated with up-regulation in the expressions (mRNA and protein) of pro-apoptotic markers viz., p53, Bax, and caspase-3, and down-regulation of anti-apoptotic marker Bcl-2. The data obtain in this study indicate that rotenone-induced cytotoxicity in HepG2 cells via ROS-induced oxidative stress and mitochondria-mediated apoptosis involving p53, Bax/Bcl-2, and caspase-3.     

Aquaporins in developing rice grains

During rice grain filling, grain moisture content and weight show dynamic changes. We focused on the expression of all 33 rice aquaporins in developing grains. Only two aquaporin genes, OsPIP2;1 and OsTIP3;1, were highly expressed in the period 10–25 days after heading (DAH). High-temperature treatment from 7 to 21 DAH abolished the dynamic up-regulation of OsPIP2;1 in the period 15–20 DAH, whereas OsTIP3;1 expression was not affected. Immunohistochemical analysis revealed that OsPIP2;1 was present in the starchy endosperm, nucellar projection, nucellar epidermis, and dorsal vascular bundles, but not in the aleurone layer. OsTIP3;1 was present in the aleurone layer and starchy endosperm. Water transport activity of recombinant OsTIP3;1 was low, in contrast to the high activity of recombinant OsPIP2;1 we reported previously. Our data suggest that OsPIP2;1 and OsTIP3;1 have distinct roles in developing grains.     

Mechanomyogram for Muscle Function Assessment: A Review

Background

Mechanomyography (MMG) has been extensively applied in clinical and experimental practice to examine muscle characteristics including muscle function (MF), prosthesis and/or switch control, signal processing, physiological exercise, and medical rehabilitation. Despite several existing MMG studies of MF, there has not yet been a review of these. This study aimed to determine the current status on the use of MMG in measuring the conditions of MFs.

Methodology/Principal Findings

Five electronic databases were extensively searched for potentially eligible studies published between 2003 and 2012. Two authors independently assessed selected articles using an MS-Word based form created for this review. Several domains (name of muscle, study type, sensor type, subject''s types, muscle contraction, measured parameters, frequency range, hardware and software, signal processing and statistical analysis, results, applications, authors'' conclusions and recommendations for future work) were extracted for further analysis. From a total of 2184 citations 119 were selected for full-text evaluation and 36 studies of MFs were identified. The systematic results find sufficient evidence that MMG may be used for assessing muscle fatigue, strength, and balance. This review also provides reason to believe that MMG may be used to examine muscle actions during movements and for monitoring muscle activities under various types of exercise paradigms.

Conclusions/Significance

Overall judging from the increasing number of articles in recent years, this review reports sufficient evidence that MMG is increasingly being used in different aspects of MF. Thus, MMG may be applied as a useful tool to examine diverse conditions of muscle activity. However, the existing studies which examined MMG for MFs were confined to a small sample size of healthy population. Therefore, future work is needed to investigate MMG, in examining MFs between a sufficient number of healthy subjects and neuromuscular patients.     

Triterpenoid saponins stimulate the sugar taste receptor cell through a G protein-mediated mechanism in the blowfly,Phormia regina

The blowfly has taste chemosensilla on the labellum. The sensory receptor cells in the chemosensillum are highly specialized for the tastes of sugar, salt and water, respectively. Previously we introduced chromosaponin I (CSI) and glycyrrhizin (GL), as sweet substances for the blowfly, Phormia regina. Application of these triterpenoid saponins induced feeding responses as well as impulses of the sugar taste receptor cell in the LL-type sensillum at a much lower concentration than that of sucrose. In the present paper, we show the involvement of G protein-mediated cascade in the CSI- and GL-responses as well as in sugar responses. CSI activates the sugar signal transduction cascade after penetrating through the membrane. On the other hand, GL exerts dual effects to stimulate the sugar signal transduction possibly by activating it inside the cell and also by interacting with the pyranose sugar receptor site. A non hydrolyzable G protein inhibitor guanosine 5′-O-(2-thiodiphosphate), GDPβS, markedly decreased the responses of the sugar receptor cell to the two triterpenoid saponins as well as the response to sucrose and fructose. These results suggest that CSI and GL are direct activators of G protein.     

The Effect of Thermophoresis on Unsteady Oldroyd-B Nanofluid Flow over Stretching Surface

There are currently only a few theoretical studies on convective heat transfer in polymer nanocomposites. In this paper, the unsteady incompressible flow of a polymer nanocomposite represented by an Oldroyd-B nanofluid along a stretching sheet is investigated. Recent studies have assumed that the nanoparticle fraction can be actively controlled on the boundary, similar to the temperature. However, in practice, such control presents significant challenges and in this study the nanoparticle flux at the boundary surface is assumed to be zero. We have used a relatively novel numerical scheme; the spectral relaxation method to solve the momentum, heat and mass transport equations. The accuracy of the solutions has been determined by benchmarking the results against the quasilinearisation method. We have conducted a parametric study to determine the influence of the fluid parameters on the heat and mass transfer coefficients.     

Genotoxic potential of copper oxide nanoparticles in human lung epithelial cells

Copper oxide nanoparticles (CuO NPs) are increasingly used in various applications. Recent studies suggest that oxidative stress may be the cause of the cytotoxicity of CuO NPs in mammalian cells. However, little is known about the genotoxicity of CuO NPs following exposure to human cells. This study was undertaken to investigate CuO NPs induced genotoxic response through p53 pathway in human pulmonary epithelial cells (A549). In addition, cytotoxicity and oxidative stress markers were also assessed. Results showed that cell viability was reduced by CuO NPs and degree of reduction was dose dependent. CuO NPs were also found to induce oxidative stress in dose-dependent manner indicated by depletion of glutathione and induction of lipid peroxidation, catalase and superoxide dismutase. The expression of Hsp70, the first tier biomarker of cellular damage was induced by CuO NPs. Further, CuO NPs up-regulated the cell cycle checkpoint protein p53 and DNA damage repair proteins Rad51 and MSH2 expression. These results demonstrate that CuO NPs possess a genotoxic potential in A549 cells which may be mediated through oxidative stress. Our short-term exposure study of high level induction of genotoxic response of CuO NPs will need to be further investigated to determine whether long-term exposure consequences may exist for CuO NPs application.