Studies on the antioxidant activity of some thiazolidinedione,imidazolidinedione and rhodanine derivatives having a flavone core

A series of flavonyl‐2,4‐thiazolidinedione, imidazolidinedione and rhodanine derivatives were tested for their antioxidant activity as scavengers of oxygen free radicals. Free radical scavenging activities, including superoxide anion radical , hydroxyl radical (HO^?) and 2,2′‐diphenyl‐1‐picrylhydrazyl free radical have been evaluated using chemiluminescence, electron paramagnetic resonance and spin trapping with 5,5‐dimethyl‐1‐pyrroline‐1‐oxide as a spin trap. Potassium superoxide in dimethylsulfoxide and 18‐crown‐6 ether were used for the production of . Hydroxyl radical was generated using the Fenton reaction. Ten of the eleven examined compounds exhibited decrease in chemiluminescence, but there were large differences in the decrease, ranging from 16% to 89%; also, two of these compounds increased light emission by about 200%. On the contrary, all compounds tested exhibited 30–68% scavenging HO^? and 25–96% scavenging the DPPH^? radical respectively. Possible mechanisms are proposed to explain the results. Copyright © 2014 John Wiley & Sons, Ltd.     

The clonogenic potential of hematopoietic stem cells and mesenchymal stromal cells in various hematologic diseases: a pilot study

Background aimsMesenchymal stromal cells (MSC) are the most popular cells used in regenerative medicine and biotechnology. The clonogenic potential of these cells is defined by colony-forming unit-fibroblasts (CFU-F). It is well known that there is an interaction between hematopoietic cells and stromal cells in disease formation pathogenesis. Therefore we hypothesized that there should be a quantitative and qualitative relationship between MSC colonies (CFU-F) and hematopoietic stem cell colonies (colony-forming unit-granulocyte-macrophages; CFU-GM) among patients with and without hematologic diseases.MethodsForty-two patients were included in this study. Patients were divided into three groups: group A, patients with hematologic malignancies (n = 20); group B, patients with bone marrow (BM) failure (n = 11); group C, patients without hematologic diseases (n = 11). BM aspirates were plated in different densities for CFU-F culture. The plating density was the same for CFU-GM culture.ResultsCFU-GM colonies grew in 90% of group A cells and all of group B and C cells (P = 0.0001). CFU-F colonies became visible on the ninth day of plating in group A and on the eight day in groups B and C. There was no statistically significant difference between the groups for the duration of CFU-F colony formation (P = 0.12). There were differences in the morphology of the colonies among the groups.ConclusionsThis is the first study that has compared the clonogenic potential of stromal cells and hematopoietic stem cells in the same subjects with and without hematologic diseases. No correlation was shown between the clonogenic potential of stromal cells and hematopoietic cells.     

A novel method to measure regional muscle blood flow continuously using NIRS kinetics information

Background

This article introduces a novel method to continuously monitor regional muscle blood flow by using Near Infrared Spectroscopy (NIRS). We demonstrate the feasibility of the new method in two ways: (1) by applying this new method of determining blood flow to experimental NIRS data during exercise and ischemia; and, (2) by simulating muscle oxygenation and blood flow values using these newly developed equations during recovery from exercise and ischemia.

Methods

Deoxy (Hb) and oxyhemoglobin (HbO₂), located in the blood ofthe skeletal muscle, carry two internal relationships between blood flow and oxygen consumption. One is a mass transfer principle and the other describes a relationship between oxygen consumption and Hb kinetics in a two-compartment model. To monitor blood flow continuously, we transfer these two relationships into two equations and calculate the blood flow with the differential information of HbO₂ and Hb. In addition, these equations are used to simulate the relationship between blood flow and reoxygenation kinetics after cuff ischemia and a light exercise. Nine healthy subjects volunteered for the cuff ischemia, light arm exercise and arm exercise with cuff ischemia for the experimental study.

Results

Analysis of experimental data of both cuff ischemia and light exercise using the new equations show greater blood flow (four to six times more than resting values) during recovery, agreeing with previous findings. Further, the simulation and experimental studies of cuff ischemia and light exercise agree with each other.

Conclusion

We demonstrate the accuracy of this new method by showing that the blood flow obtained from the method agrees with previous data as well as with simulated data. We conclude that this novel continuous blood flow monitoring method can provide blood flow information non-invasively with NIRS.

     

Preparation and characterization of epoxy-functionalized magnetic chitosan beads: laccase immobilized for degradation of reactive dyes

Cross-linked magnetic chitosan beads were prepared by phase-inversion technique in the presence of epichlorohydrin under alkaline condition, and used for covalent immobilization of laccase. The activity of the immobilized laccase on the magnetic chitosan was about 260 U (g/dry beads) with an enzyme loading of about 16.33 ± 0.39 mg [(g/dry beads) mg/g]. Kinetic parameters, V _max and K _m values were determined as 21.7 U/mg protein and 9.4 μM for free enzyme, and 15.6 U/mg protein and 19.7 μM for the immobilized laccase, respectively. The operational and thermal stabilities of the immobilized laccase were improved compared to free counterpart. The immobilized laccase was operated in a batch reactor for the decolorization of reactive dyes from aqueous solution. The laccase immobilized on magnetic chitosan beads was very effective for removal of textile dyes from aqueous solution which creates an important environmental problem in the discharged textile dying solutions.     

THE INFLUENCE OF DIETARY α‐SOLANINE ON THE WAXMOTH Galleria mellonella L

Plant allelochemicals are nonnutritional chemicals that interfere with the biology of herbivores. We posed the hypothesis that ingestion of a glycoalkaloid allelochemical, α‐solanine, impairs biological parameters of greater wax moths Galleria mellonella. To test this idea, we reared wax moths on artificial diets with 0.015, 0.15, or 1.5 mg/100 g diet of α‐solanine. Addition of α‐solanine to the diet affected survival of seventh‐instar larvae, pupae, and adults; and female fecundity and fertility. The diet containing the highest α‐solanine concentration led to decreased survivorship, fecundity, and fertility. The diets supplemented with α‐solanine led to increased malondialdehyde and protein carbonyl contents in midgut and fat body and the effect was dose‐dependent. Dietary α‐solanine led to increased midgut glutathione S‐transferase activity and to decreased fat body glutathione S‐transferase activitiy. We infer from these findings that α‐solanine influences life history parameters and antioxidative enzyme activities in the midgut and fat body of G. mellonella.     

Further investigation of the mechanism of <Emphasis Type="Italic">Vitreoscilla</Emphasis> hemoglobin (VHb) protection from oxidative stress in <Emphasis Type="Italic">Escherichia coli</Emphasis>

In Escherichia coli, Vitreoscilla hemoglobin (VHb) protects against oxidative stress, perhaps, in part, by oxidizing OxyR. Here this protection, specifically VHb-associated effects on superoxide dismutase (SOD) and catalase levels, was examined. Exponential or stationary phase cultures of SOD⁺ or SOD⁻ E. coli strains with or without VHb and oxyR antisense were treated with 2 mM hydrogen peroxide without sublethal peroxide induction, and compared to untreated control cultures. The hydrogen peroxide treatment was toxic to both SOD⁺ and SOD⁻ cells, but much more to SOD⁻ cells; expression of VHb in SOD⁺ strains enhanced this toxicity. In contrast, the presence of VHb was generally associated in the SOD⁺ background with a modest increase in SOD activity that was not greatly affected by oxyR antisense or peroxide treatment. In both SOD⁺ and SOD⁻ backgrounds, VHb was associated with higher catalase activity both in the presence and absence of peroxide. Contrary to its stimulatory effects in stationary phase, in exponential phase oxyR antisense generally decreased VHb levels.     

A Chemical Screening Procedure for Glucocorticoid Signaling with a Zebrafish Larva Luciferase Reporter System

Glucocorticoid stress hormones and their artificial derivatives are widely used drugs to treat inflammation, but long-term treatment with glucocorticoids can lead to severe side effects. Test systems are needed to search for novel compounds influencing glucocorticoid signaling in vivo or to determine unwanted effects of compounds on the glucocorticoid signaling pathway. We have established a transgenic zebrafish assay which allows the measurement of glucocorticoid signaling activity in vivo and in real-time, the GRIZLY assay (Glucocorticoid Responsive In vivo Zebrafish Luciferase activitY). The luciferase-based assay detects effects on glucocorticoid signaling with high sensitivity and specificity, including effects by compounds that require metabolization or affect endogenous glucocorticoid production. We present here a detailed protocol for conducting chemical screens with this assay. We describe data acquisition, normalization, and analysis, placing a focus on quality control and data visualization. The assay provides a simple, time-resolved, and quantitative readout. It can be operated as a stand-alone platform, but is also easily integrated into high-throughput screening workflows. It furthermore allows for many applications beyond chemical screening, such as environmental monitoring of endocrine disruptors or stress research.     

Experimentally induced puromycine aminonucleoside nephrosis (PAN) in rats: evaluation of angiogenic protein platelet-derived endothelial cell growth factor (PD-ECGF) expression in glomeruli

Background

In experimentally induced puromycine aminonucleoside nephrosis (PAN) animal models, nephrotic syndrome with minimal change disease and focal and segmental sclerosis-like nephritis similar to that in human is demonstrated; however, the real mechanism of PAN is not yet elucidated. Platelet derived endothelial cell growth factor (PD-ECGF), an endothelial mitogen protein, is believed to take part in microvessel formation and in stimulation of angiogenesis and its expression has not been totally demonstrated in PAN rats yet. In this study, we aimed to examine PD-ECGF expression in acute and chronic PAN induced in rats and find out the association between its expression and the stages of angiogenesis in kidney.

Methods

For the experiment, twenty-four Male Wistar Albino rats were used and divided into four groups; control group (n = 6), pre-proteinuria group (n = 6), acute group (n = 6) and chronic group (n = 6). We compared statistically all data by One-way ANOVA Test followed by Dunn Multiple Comparison Test.

Results

Proteinurea levels in control and pre-proteinuria groups were not statistically different; however, it was remarkably higher in the acute nephrosis group and significantly greater in the chronic nephrosis group than control group (p < 0.0025). In pre-proteinuria group, the serum albumin and creatinine clearances also did not significantly differ from the control group. On the other hand, in the acute and chronic nephrosis groups, serum albumin and creatinine clearances progressively decreased (p < 0.05). In our immunohistochemical studies, we showed elevated PD-ECGF expression in glomeruli of acute and chronic PAN rats. Microscopic and ultrastructural appearances of the glomeruli of acute and chronic PAN showed various sequential steps of angiogenesis, macrophages and immature capillaries with primitive lumens and apoptotic endothelial cells in the increased mesangial matrix.

Conclusions

It is reported that acute and chronic PAN progressively increase PD-ECGF expression and following induction of angiogenesis in the affected glomeruli.     

Comparative evaluation of the microplate nitrate reductase assay and the rezasurin microtitre assay for the rapid detection of multidrug resistant Mycobacterium tuberculosis clinical isolates

The microplate nitrate reductase assay (MNRA) and the rezasurin microtitre assay (REMA) were used for the susceptibility testing of 73 clinical isolates and the results were compared with those that were obtained using the Bactec 460 TB and Bactec MGIT 960 systems. The REMA and the MNRA were performed in 96-well plates. For the REMA, the concentrations of isoniazid (INH) and rifampicin (RIF) ranged from 1.0-0.01 μg/mL and 2.0-0.03 μg/mL, respectively. For the MNRA, the INH concentration was between 1.0-0.03 μg/mL and the RIF concentration was between 2.0-0.06 μg/mL. For the MNRA, the sensitivity, specificity, positive predictive value, negative predictive value and INH/RIF agreement were 100/95.6, 97.6/100, 96.8/100, 100/98 and 98.6/98.6, respectively, and for the REMA, they were 100/91.3, 90.4/100, 88.5/100, 100/96.1 and 94.5/97.2, respectively. Our data suggest that these two rapid, low-cost methods may be inexpensive, alternative assays for the rapid detection of multidrug resistant tuberculosis in low-income countries.     

A chemical screening system for glucocorticoid stress hormone signaling in an intact vertebrate

Glucocorticoids, steroid hormones of the adrenal gland, are an integral part of the stress response and regulate glucose metabolism. Natural and synthetic glucocorticoids are widely used in anti-inflammatory therapy but can have severe side effects. In vivo tests are needed to identify novel glucocorticoids and to screen compounds for unwanted effects on glucocorticoid signaling. We created the Glucocorticoid Responsive In vivo Zebrafish Luciferase activitY assay to monitor glucocorticoid signaling in vivo. The GRIZLY assay detects stress-induced glucocorticoid production in single zebrafish larvae, measures disruption of glucocorticoid signaling by an organotin pollutant metabolite, and specifically identifies a compound stimulating endogenous glucocorticoid production in a chemical screen. Our assay has broad applications in stress research, environmental monitoring, and drug discovery.