Metal Ions in Activated Carbon Improve the Detection Efficiency of Aflatoxin-Producing Fungi

Aflatoxins (AF), produced by several Aspergillus species, are visible under ultraviolet light if present in high amounts. AF detection can be improved by adding activated carbon, which enhances the observation efficiency of weakly AF-producing fungi. However, commercial activated carbon products differ in their characteristics, making it necessary to investigate which characteristics affect method reproducibility. Herein, the addition of 10 activated carbon products resulted in different AF production rates in each case. The differences in the production of aflatoxin G1 (AFG1) were roughly correlated to the observation efficiency in the plate culture. Trace element analysis showed that the concentrations of several metal ions differed by factors of >100, and the carbons that most effectively increased AFG1 production contained higher amounts of metal ions. Adding 5 mg L−1 Fe or Mg ions increased AFG1 production even without activated carbon. Furthermore, co-addition of both ions increased AFG1 production stably with the addition of carbon. When varying the concentration of additives, only AFG1 production increased in a concentration-dependent manner, while the production of all the other AFs decreased or remained unchanged. These findings suggest that a key factor influencing AF production is the concentration of several metal ions in activated carbon and that increasing AFG1 production improves AF detectability.

Download Full-text

Antioxidant and Prooxidant Effects of Metal Dafonates on the NADPH-Dependent Lipid Peroxidation in the Murine Hepatic Microsomal System

Metal-Based Drugs ◽

10.1155/mbd.1999.169 ◽

1999 ◽

Vol 6 (3) ◽

pp. 169-175 ◽

Cited By ~ 1

Author(s):

M. Gupta ◽

R. K. Kale ◽

P. P. Kulkarni ◽

S. B. Padhye

Keyword(s):

Lipid Peroxidation ◽

Metal Ions ◽

The Other ◽

Inhibition Constant ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Other Hand ◽

Significant Reversal

Dafone inhibits the lipid peroxidation significantly in a concentration dependent manner. The inhibition was found to be an uncompetitive type with the inhibition constant (Ki) of 62.5 μM On the other hand complexation with metal ions results in a significant reversal from antioxidant to pro-oxidant properties for the resulting complexes which are cationic and with associated halometallate anions. The nature of the potentiation in case of the ferric compound was of competitive type with activation constant (Ka) having the value 32.5 μM . The neutral copper-dafonate complex, however, inhibits lipid peroxidation with increase in concentration.

Download Full-text

Fluorescein-Labeled Starch Maleate Nanoparticles as Sensitive Fluorescent Sensing Probes for Metal Ions

Journal of Nanomaterials ◽

10.1155/2014/108359 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Suk Fun Chin ◽

Aressa Azman ◽

Suh Cem Pang ◽

Sing Muk Ng

Keyword(s):

Particle Size ◽

Metal Ions ◽

Self Assembly ◽

Detection Limits ◽

Emission Wavelength ◽

Dependent Manner ◽

Ethanolic Solution ◽

Concentration Dependent Manner ◽

Maximum Emission ◽

Fluorescent Sensing

Fluorescein 5(6)-isothiocyanate starch maleate (FISM) nanoparticles were prepared by covalently attached fluorescein 5(6)-isothiocyanate (FITC) with starch maleate. FISM nanoparticles with a mean particle size of 87 nm were formed via self-assembly upon precipitation in ethanolic solution. FISM nanoparticles were strongly fluorescent with maximum emission wavelength of 518 nm. The fluorescence of FISM nanoparticles can be quenched by silver (Ag+) and lead (Pb2+) ions in a concentration dependent manner. We have demonstrated the first use of FISM nanoparticles as cheap and effective fluorescent sensing probes for Ag+and Pb2+ions with detection limits as low as 2.55×10−5 M and 3.64×10−5 M, respectively.

Download Full-text

Inhibitory effect of Sphagnum palustre extract and its bioactive compounds on aromatase activity

Bangladesh Journal of Pharmacology ◽

10.3329/bjp.v11i3.26776 ◽

2016 ◽

Vol 11 (3) ◽

pp. 661

Author(s):

Hee Jeong Eom ◽

Yong Joo Park ◽

Hee Rae Kang ◽

Ha Ryong Kim ◽

In Jae Bang ◽

...

Keyword(s):

Video Clip ◽

Inhibitory Effect ◽

The Other ◽

Aromatase Activity ◽

Dependent Manner ◽

Inhibitory Effects ◽

Aromatase Inhibition ◽

Concentration Dependent Manner ◽

Cardiac Pain ◽

Sphagnum Palustre

Sphagnum palustre (a moss) has been traditionally used in Korea for the cure of several diseases such as cardiac pain and stroke. In this research, the inhibitory effect of S. palustre on aromatase (cytochrome P450 19, CYP19) activity was studied. [1β-3H] androstenedione was used as a substrate and incubated with S. palustre extract and recombinant human CYP19 in the presence of NADPH. S. palustre extract inhibited aromatase in a concentration-dependent manner (IC50 value: 36.4 ± 8.1 µg/mL). To elucidate the major compounds responsible for the aromatase inhibitory effects of S. palustre extract, nine compounds were isolated from the extract and tested for their inhibition of aromatase activity. Compounds 1, 6, and 7 displayed aromatase inhibition, while the inhibition by the other compounds was negligible.Video Clip<a href="https://youtube.com/v/n6xeo3RXJVY">Aromatase enzyme activity:</a> 4 min 16 sec

Download Full-text

Antiausterity Activity of Arctigenin Enantiomers: Importance of (2R,3R)-Absolute Configuration

Natural Product Communications ◽

10.1177/1934578x1400900123 ◽

2014 ◽

Vol 9 (1) ◽

pp. 1934578X1400900 ◽

Cited By ~ 1

Author(s):

Suresh Awale ◽

Mamoru Kato ◽

Dya Fita Dibwe ◽

Feng Li ◽

Chika Miyoshi ◽

...

Keyword(s):

Cytotoxic Activity ◽

Cancer Cells ◽

Absolute Configuration ◽

The Other ◽

Dependent Manner ◽

Meoh Extract ◽

Concentration Dependent Manner ◽

Akt Activation ◽

Other Hand

From a MeOH extract of powdered roots of Wikstroema indica, six dibenzyl-γ-butyrolactone-type lignans with (2 S,3 S)-absolute configuration [(+)-arctigenin (1), (+)-matairesinol (2), (+)-trachelogenin (3), (+)-nortrachelogenin (4), (+)-hinokinin (5), and (+)-kusunokinin (6)] were isolated, whereas three dibenzyl-γ-butyrolactone-type lignans with (2 R,3 R)-absolute configuration [(-)-arctigenin (1), (-)-matairesinol (2), (-)-trachelogenin (3)] were isolated from Trachelospermum asiaticum. The in vitro preferential cytotoxic activity of the nine compounds was evaluated against human pancreatic PANC-1 cancer cells in nutrient-deprived medium (NDM), but none of the six lignans (1–6) with (2 S,3 S)-absolute configuration showed preferential cytotoxicity. On the other hand, three lignans (1*–3*) with (2 R,3 R)-absolute configuration exhibited preferential cytotoxicity in a concentration-dependent manner with PC50 values of 0.54, 6.82, and 5.85 μM, respectively. Furthermore, the effect of (-)- and (+)-arctigenin was evaluated against the activation of Akt, which is a key process in the tolerance to nutrition starvation. Interestingly, only (-)-arctigenin (1*) strongly suppressed the activation of Akt. These results indicate that the (2 R,3 R)-absolute configuration of (-)-enantiomers should be required for the preferential cytotoxicity through the inhibition of Akt activation.

Download Full-text

Comparative Intracellular (THP-1 Macrophage) and Extracellular Activities of β-Lactams, Azithromycin, Gentamicin, and Fluoroquinolones against Listeria monocytogenes at Clinically Relevant Concentrations

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.46.7.2095-2103.2002 ◽

2002 ◽

Vol 46 (7) ◽

pp. 2095-2103 ◽

Cited By ~ 78

Author(s):

Stéphane Carryn ◽

Françoise Van Bambeke ◽

Marie-Paule Mingeot-Leclercq ◽

Paul M. Tulkens

Keyword(s):

Listeria Monocytogenes ◽

Conventional Therapy ◽

The Other ◽

Intracellular Bacteria ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Cellular Accumulation ◽

Intracellular Activities ◽

The Difference ◽

In Cells

ABSTRACT The activities of ampicillin, meropenem, azithromycin, gentamicin, ciprofloxacin, and moxifloxacin against intracellular hemolysin-positive Listeria monocytogenes were measured in human THP-1 macrophages and were compared with the extracellular activities observed in broth. All extracellular concentrations were adjusted to explore ranges that are clinically achievable in human serum upon conventional therapy. In broth, ampicillin, meropenem, and azithromycin were only bacteriostatic, whereas gentamicin, ciprofloxacin, and moxifloxacin were strongly bactericidal in a concentration-dependent manner. In cells, ampicillin, meropenem, azithromycin, and ciprofloxacin were slightly bactericidal (0.3- to 0.8-log CFU reductions), moxifloxacin was strongly bactericidal (2.1-log CFU reduction), and gentamicin was virtually inactive. The difference in the efficacies of moxifloxacin and ciprofloxacin in cells did not result from a difference in levels of accumulation in cells (6.96 ± 1.05 versus 7.75 ± 1.03) and was only partially explainable by the difference in the MICs (0.58 ± 0.04 versus 1.40 ± 0.17 mg/liter). Further analysis showed that intracellular moxifloxacin expressed only approximately 1/7 of the activity demonstrated against extracellular bacteria and ciprofloxacin expressed only 1/15 of the activity demonstrated against extracellular bacteria. Gentamicin did not increase the intracellular activities of the other antibiotics tested. The data suggest (i) that moxifloxacin could be of potential interest for eradication of the intracellular forms of L. monocytogenes, (ii) that the cellular accumulation of an antibiotic is not the only determinant of its intracellular activity (for fluoroquinolones, it is actually a self-defeating process as far as activity is concerned), and (iii) that pharmacodynamics (activity-to-concentration relationships) need to be considered for the establishment of efficacy against intracellular bacteria, just as they are for the establishment of efficacy against extracellular infections.

Download Full-text

Modification of intracellular calcium concentration in cardiomyocytes by inhibition of sarcolemmal Na+/H+ exchanger

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00535.2006 ◽

2006 ◽

Vol 291 (6) ◽

pp. H2790-H2800 ◽

Cited By ~ 14

Author(s):

Harjot K. Saini ◽

Naranjan S. Dhalla

Keyword(s):

Sarcoplasmic Reticulum ◽

Intracellular Calcium ◽

Calcium Concentration ◽

Extracellular Ph ◽

The Other ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Rat Cardiomyocytes ◽

Intracellular Ca ◽

Isolated Rat

Although the Na+/H+ exchanger (NHE) is considered to be involved in regulation of intracellular Ca2+ concentration ([Ca2+]i) through the Na+/Ca2+ exchanger, the exact mechanisms of its participation in Ca2+ handling by cardiomyocytes are not fully understood. Isolated rat cardiomyocytes were treated with or without agents that are known to modify Ca2+ movements in cardiomyocytes and exposed to an NHE inhibitor, 5-( N-methyl- N-isobutyl)amiloride (MIA). [Ca2+]i in cardiomyocytes was measured spectrofluorometrically with fura 2-AM in the absence or presence of KCl, a depolarizing agent. MIA increased basal [Ca2+]i and augmented the KCl-induced increase in [Ca2+]i in a concentration-dependent manner. The MIA-induced increase in basal [Ca2+]i was unaffected by extracellular Ca2+, antagonists of the sarcolemmal (SL) L-type Ca2+ channel, and inhibitors of the SL Na+/Ca2+ exchanger, SL Ca2+ pump ATPase and mitochondrial Ca2+ uptake. However, the MIA-induced increase in basal [Ca2+]i was attenuated by inhibitors of SL Na+-K+-ATPase and sarcoplasmic reticulum (SR) Ca2+ transport. On the other hand, the MIA-mediated augmentation of the KCl response was dependent on extracellular Ca2+ concentration and attenuated by agents that inhibit SL L-type Ca2+ channels, the SL Na+/Ca2+ exchanger, SL Na+-K+-ATPase, and SR Ca2+ release channels and the SR Ca2+ pump. However, the effect of MIA on the KCl-induced increase in [Ca2+]i remained unaffected by treatment with inhibitors of SL Ca2+ pump ATPase and mitochondrial Ca2+ uptake. MIA and a decrease in extracellular pH lowered intracellular pH and increased basal [Ca2+]i, whereas a decrease in extracellular pH, in contrast to MIA, depressed the KCl-induced increase in [Ca2+]i in cardiomyocytes. These results suggest that NHE may be involved in regulation of [Ca2+]i and that MIA-induced increases in basal [Ca2+]i, as well as augmentation of the KCl-induced increase in [Ca2+]i, in cardiomyocytes are regulated differentially.

Download Full-text

Block of current through single calcium channels by Fe, Co, and Ni. Location of the transition metal binding site in the pore.

The Journal of General Physiology ◽

10.1085/jgp.97.2.351 ◽

1991 ◽

Vol 97 (2) ◽

pp. 351-367 ◽

Cited By ~ 54

Author(s):

B D Winegar ◽

R Kelly ◽

J B Lansman

Keyword(s):

Metal Binding ◽

The Other ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Coulombic Interactions ◽

Rate Limiting Step ◽

Ion Size ◽

Rate Limiting ◽

Kinetics Of ◽

Ca2 Channels

The blocking actions of Fe2+, Co2+, and Ni2+ on unitary currents carried by Ba2+ through single dihydropyridine-sensitive Ca2+ channels were recorded from cell-attached patches on myotubes from the mouse C2 cell line. Adding millimolar concentrations of blocker to patch electrodes containing 110 mM BaCl2 produced discrete excursions to the closed channel level. The kinetics of blocking and unblocking were well described with a simple model of open channel block. Hyperpolarization speeded the exit of all of the blockers from the channel, as expected if the blocking site resides within the pore. The block by Ni2+ differs from that produced by Fe2+ and Co2+ because Ni2+ enters the channel approximately 20 times more slowly and exits approximately 50 times more slowly. Ni2+ also differs from the other transition metals because at millimolar concentrations it reduces the amplitude of the unitary current in a concentration-dependent manner. The results are consistent with the idea that the rate-limiting step for ion entry into the channel is water loss at its inner coordination sphere; unblocking, on the other hand, cannot be explained in terms of simple coulombic interactions arising from differences in ion size.

Download Full-text

Trace Element Analysis of The Otani Collection's Dunhuang and Turfan Manuscripts by PIXE

International Journal of PIXE ◽

10.1142/s0129083599000565 ◽

1999 ◽

Vol 09 (03n04) ◽

pp. 453-464 ◽

Cited By ~ 2

Author(s):

M. KOHNO ◽

K. YOSHIDA ◽

K. MORITANI ◽

K. NORIZAWA ◽

K. ENAMI ◽

...

Keyword(s):

Trace Elements ◽

Iron Content ◽

Trace Element Analysis ◽

The Other ◽

Late Qing Dynasty ◽

Element Analysis ◽

Cd Rom ◽

Bromine Content ◽

Late Qing ◽

Handmade Paper

In order to classify the Otani Collection's Dunhuang and Turfan manuscripts, their trace elements were analyzed by PIXE. The paper samples of these manuscripts were fallen off when they were photographed for a CD-ROM catalog. These samples were very small and their size was less than several millimeters. In addition, some paper fragments dating from the late Edo-era of Japan and the late Qing Dynasty of China, and modern Japanese handmade paper were analyzed using PIXE and NAA. Quite interesting results were obtained when analyzing the trace elements – Na , Mg , Al , Si , S , Cl , K , Ca , Sc , Mn , Fe , Cu , Zn , As , Br , Sr , Ba , Pb , La , Sm . It was found that Dunhuang and Turfan papers of the Otani Collection were characterized by its highest iron and bromine content. The reason of the highest iron content probably originates in their making process and/or depends on their preservative environment. On the other hand, it became clear as for the highest bromine content that the origin is from fumigation of methyl bromide.

Download Full-text

Analysis of Burmese and Thai Rubies by PIXE

Applied Spectroscopy ◽

10.1366/0003702884428752 ◽

1988 ◽

Vol 42 (1) ◽

pp. 44-48 ◽

Cited By ~ 21

Author(s):

S. M. Tang ◽

S. H. Tang ◽

T. S. Tay ◽

A. T. Retty

Keyword(s):

Trace Element ◽

Trace Element Analysis ◽

The Other ◽

Element Analysis ◽

X Ray ◽

Other Hand ◽

Low Concentrations

Trace element analysis of 60 Burmese and Thai rubies by using the technique of proton-induced x-ray emission was carried out. It was found that the Burmese rubies contained higher concentrations of all impurities except iron. Our results also reveal that vanadium and iron are useful indicators for Burmese and Thai ruby attribution. The Thai rubies have high contents of iron and very low concentrations of vanadium. On the other hand, all the Burmese rubies examined contain significant amounts of vanadium, and their iron contents are, on the average, four times lower than those in the Thai rubies.

Download Full-text

Flow-induced Dilation of Rat Coronary Microvessels Is Attenuated by Isoflurane but Enhanced by Halothane

Anesthesiology ◽

10.1097/00000542-199807000-00020 ◽

1998 ◽

Vol 89 (1) ◽

pp. 132-142 ◽

Cited By ~ 7

Author(s):

Kyung W. Park ◽

Hai B. Dai ◽

Edward Lowenstein ◽

Frank W. Sellke

Keyword(s):

Minimum Alveolar Concentration ◽

Detection System ◽

Volatile Anesthetics ◽

No Synthase ◽

The Other ◽

Dependent Manner ◽

Cyclooxygenase Inhibitor ◽

Concentration Dependent Manner ◽

Synthase Inhibitor

Background Volatile anesthetics attenuate agonist-induced endothelium-dependent vasodilation of coronary arteries. This study considered the hypothesis that the anesthetics may also attenuate flow-induced endothelium-dependent vasodilation. Methods Rat subepicardial arteries of approximately 100 microm were monitored for diameter changes in vitro by a video detection system, with the midpoint luminal pressure held constant at 40 mmHg but the pressure gradient (and therefore flow) across each vessel increased from 0 to 80 mmHg, in the presence or absence of 1 or 2 minimum alveolar concentration (MAC) isoflurane or 1 or 2 MAC halothane, with or without 10 microM of the nitric oxide (NO) synthase inhibitor NG-nitro-L-arginine (L-NNA) or 10 microM of the cyclooxygenase inhibitor indomethacin. Results Flow-induced dilation was attenuated by L-NNA or indomethacin (p < 0.001 each). It was attenuated by isoflurane in a concentration-dependent manner (P < 0.001). Attenuation by 2 MAC isoflurane persisted even in the presence of L-NNA (P < 0.01) or indomethacin (P < 0.05). On the other hand, flow-induced dilation was enhanced by 2 MAC halothane (P < 0.05). Halothane at 1 MAC had no significant effect. Enhancement by 2 MAC halothane was evident in the presence of indomethacin (P < 0.05) but not L-NNA (P = 0.40). Conclusions In rat subepicardial arteries, flow-induced dilation is endothelium-dependent and mediated by both NO and a prostanoid. Isoflurane attenuates flow-induced dilation, possibly by decreasing synthesis, the action of NO and a prostanoid, or both, whereas halothane enhances it, possibly by increasing synthesis, the action of NO, or both.

Download Full-text