THE RELATIONSHIP BETWEEN THE GLUTATHIONE CONTENT OF RAT ERYTHROCYTES AND THEIR HEMOLYSIS BY VARIOUS AGENTS IN VITRO

1960 ◽  
Vol 38 (1) ◽  
pp. 981-987 ◽  
Author(s):  
C. C. Tsen ◽  
H. B. Collier
Keyword(s):  
Heavy Metal ◽  
Silver Nitrate ◽  
Mercuric Chloride ◽  
Direct Action ◽  
The Other ◽  
Rat Erythrocytes ◽  
Experimental Conditions ◽  
Low Levels ◽  
The Relationship

Erythrocytes from rats on tocopherol-deficient diets are susceptible to hemolysis by dialuric acid or by shaking in an atmosphere of oxygen, whereas the erythrocytes from rats on tocopherol-supplemented diets are relatively insusceptible. The erythrocytes from the tocopherol-deficient and tocopherol-supplemented rats initially showed identical levels of free glutathione as determined by the alloxan "305" method; treatment with dialuric acid or exposure to oxygen reduced the glutathione levels in both groups of cells, yet in no case did the extent of hemolysis parallel the decrease in glutathione.Treatment of rat erythrocytes with selenite or iodoacetate or N-ethylmaleimide decreased the glutathione content of the cells to very low levels, yet there was little hemolysis. Silver nitrate, mercuric chloride, or p-chloromercuribenzoate, on the other hand, could cause complete hemolysis with little or no decrease in the levels of erythrocyte free glutathione. There were no significant differences between the erythrocytes from tocopherol-deficient and tocopherol-supplemented animals in these experiments.It is concluded that the susceptibility to hemolysis, under our experimental conditions, is not related to the level of erythrocyte glutathione. The heavy-metal sulphydryl reagents probably cause hemolysis by a direct action upon the erythrocyte membrane.

THE RELATIONSHIP BETWEEN THE GLUTATHIONE CONTENT OF RAT ERYTHROCYTES AND THEIR HEMOLYSIS BY VARIOUS AGENTS IN VITRO

1960 ◽  
Vol 38 (9) ◽  
pp. 981-987 ◽  
Author(s):  
C. C. Tsen ◽  
H. B. Collier
Keyword(s):  
Heavy Metal ◽  
Silver Nitrate ◽  
Mercuric Chloride ◽  
Direct Action ◽  
The Other ◽  
Rat Erythrocytes ◽  
Experimental Conditions ◽  
Low Levels ◽  
The Relationship

Erythrocytes from rats on tocopherol-deficient diets are susceptible to hemolysis by dialuric acid or by shaking in an atmosphere of oxygen, whereas the erythrocytes from rats on tocopherol-supplemented diets are relatively insusceptible. The erythrocytes from the tocopherol-deficient and tocopherol-supplemented rats initially showed identical levels of free glutathione as determined by the alloxan "305" method; treatment with dialuric acid or exposure to oxygen reduced the glutathione levels in both groups of cells, yet in no case did the extent of hemolysis parallel the decrease in glutathione.Treatment of rat erythrocytes with selenite or iodoacetate or N-ethylmaleimide decreased the glutathione content of the cells to very low levels, yet there was little hemolysis. Silver nitrate, mercuric chloride, or p-chloromercuribenzoate, on the other hand, could cause complete hemolysis with little or no decrease in the levels of erythrocyte free glutathione. There were no significant differences between the erythrocytes from tocopherol-deficient and tocopherol-supplemented animals in these experiments.It is concluded that the susceptibility to hemolysis, under our experimental conditions, is not related to the level of erythrocyte glutathione. The heavy-metal sulphydryl reagents probably cause hemolysis by a direct action upon the erythrocyte membrane.

In Vitro Binding of Zearalenone to Different Adsorbents

2005 ◽  
Vol 68 (3) ◽  
pp. 613-615 ◽  
Author(s):  
DANTE J. BUENO ◽  
LILIANA DI MARCO ◽  
GUILLERMO OLIVER ◽  
ALICIA BARDÓN
Keyword(s):  
Activated Carbon ◽  
Calcium Sulfate ◽  
Fusarium Species ◽  
The Other ◽  
Experimental Conditions ◽  
In Vitro Binding ◽  
Other Hand ◽  
Vitro Binding ◽  
Dose Levels

Zearalenone (ZEA) is a potent estrogenic metabolite produced by some Fusarium species. No treatment has been successfully employed to get rid of the ZEA contained in foods. This study was conducted to evaluate the ability (adsorptive power) of five adsorbents—activated carbon, bentonite, talc, sandstone, and calcium sulfate—to trap ZEA in vitro. Activated carbon was the best adsorbent, binding 100% ZEA (pH 3 and 7.3) at 0.1, 0.25, 0.5, and 1% dose levels. Bentonite, talc, and calcium sulfate were less efficient than activated carbon but still could bind ZEA to some extent. On the other hand, sandstone was inactive in the experimental conditions employed. Our results indicate that activated carbon could be a good candidate for detoxification of ZEA present in foods.

scholarly journals Specificity and Regulation of Interaction between the PII and AmtB1 Proteins in Rhodospirillum rubrum

2007 ◽  
Vol 189 (19) ◽  
pp. 6861-6869 ◽  
Author(s):  
David M. Wolfe ◽  
Yaoping Zhang ◽  
Gary P. Roberts
Keyword(s):  
Rhodospirillum Rubrum ◽  
Regulatory Protein ◽  
The Other ◽  
Ammonia Gas ◽  
Gas Channel ◽  
Energy Sensor ◽  
Low Levels

ABSTRACT The nitrogen regulatory protein PII and the ammonia gas channel AmtB are both found in most prokaryotes. Interaction between these two proteins has been observed in several organisms and may regulate the activities of both proteins. The regulation of their interaction is only partially understood, and we show that in Rhodospirillum rubrum one PII homolog, GlnJ, has higher affinity for an AmtB1-containing membrane than the other two PII homologs, GlnB and GlnK. This interaction strongly favors the nonuridylylated form of GlnJ and is disrupted by high levels of 2-ketoglutarate (2-KG) in the absence of ATP or low levels of 2-KG in the presence of ATP. ADP inhibits the destabilization of the GlnJ-AmtB1 complex in the presence of ATP and 2-KG, supporting a role for PII as an energy sensor measuring the ratio of ATP to ADP. In the presence of saturating levels of ATP, the estimated Kd of 2-KG for GlnJ bound to AmtB1 is 340 μM, which is higher than that required for uridylylation of GlnJ in vitro, about 5 μM. This supports a model where multiple 2-KG and ATP molecules must bind a PII trimer to stimulate release of PII from AmtB1, in contrast to the lower 2-KG requirement for productive uridylylation of PII by GlnD.

A novel mechanism of olanzapine-induced lipid accumulation

2011 ◽  
Vol 26 (S2) ◽  
pp. 906-906 ◽  
Author(s):  
S. Dzitoyeva ◽  
H. Chen ◽  
R. Manev ◽  
H. Manev
Keyword(s):  
Lipid Content ◽  
Direct Action ◽  
Inhibitory Effect ◽  
Experimental Conditions ◽  
Cell Content ◽  
Metabolic Alterations ◽  
Low Concentrations ◽  
Mrna Content ◽  
Quantitative Western Blot

IntroductionSecond generation antipsychotic drugs (SGADs) including olanzapine trigger adverse metabolic alterations possibly by a direct action on adipocytes.Objectives and aimsThe system of the inflammatory 5-lipoxygenase (5-LOX) and its activating protein (FLAP) have been implicated in lipid dysfunction in obesity. We investigated whether this system could participate in the adipogenic action of olanzapine.MethodsExperiments were performed in 3T3-L1 adipocytes in vitro. Cells were treated with olanzapine and a FLAP inhibitor MK-886. Their lipid content, 5-LOX and FLAP mRNA content, and FLAP protein content were measured.ResultsOlanzapine treatment did not affect the cell content of 5-LOX mRNA; however, it decreased FLAP mRNA content at day five but not 24 hours after olanzapine addition. The inhibitory effect of olanzapine on FLAP expression was confirmed by quantitative Western blot assays. In the absence of a FLAP inhibitor, low concentrations of olanzapine (0.5 and 5 μM) increased lipid content only by about 13% (compared to about a 56% increase induced by 50 μM olanzapine) whereas in the presence of MK-886 these concentrations of olanzapine produced lipid increases comparable to the increase caused by 50 μM. In these experimental conditions, MK-886 alone did not alter the cell content of lipids.Conclusions5-LOX system may be involved in lipid dysfunction not only in conditions of obesity but possibly in SGAD-related metabolic alterations. The known polymorphism in the genes of the human 5-LOX system could play a role in setting a variable individual susceptibility to the metabolic side effects of SGADs.

Anionic and cationic exchange mechanisms in the skin of anurans, with special reference to Leptodactylidae in vivo

1971 ◽  
Vol 262 (842) ◽  
pp. 163-174 ◽  
Keyword(s):  
Transport Mechanism ◽  
Selective Inhibition ◽  
The Other ◽  
Sodium Absorption ◽  
Experimental Conditions ◽  
Net Flux ◽  
Cationic Exchange

In several species of anurans, the in vivo skin has been shown to absorb Na + and Cl - independently from dilute external solutions. That the mechanism for sodium absorption is different from that of chloride absroption is born out by the following: (1) Either of these ions is absorbed without an accompanying ion when this latter is impermeant. (2) From NaCl solutions there can be an unequal absorption of sodium and chloride. (3) A selective inhibition of the absorption of one of the ions can be produced experimentally, while the net flux of the other remains unchanged. In all these situations, the absorbed ion has to be exchanged against an endogenous ion of the same charge. In Calyptocephalella gayi , H + and HCO - 3 are exchanged against sodium and chloride respectively. A comparison of the relationships between H + excretion and Na + absorption in vivo skins and shortcircuited in vitro skins shows that in the latter no H + excretion occurs, only the Na + transport being maintained under these experimental conditions. From this, one must conclude that the active Na + transport is the motive factor of the transport mechanism. H + excretion by the in vivo skin plays the role of physiologically short-circuiting the Na + transport.

The relationship of Zonocerus variegatus (L.) (Acridoidea: Pyrgomorphidae) with cassava (Manihot esculenta)

1977 ◽  
Vol 67 (3) ◽  
pp. 391-404 ◽  
Author(s):  
E. A. Bernays ◽  
R. F. Chapman ◽  
E. M. Leather ◽  
A. R. McCaffery ◽  
W. W. D. Modder
Keyword(s):  
Hydrogen Cyanide ◽  
Manihot Esculenta ◽  
Normal Growth ◽  
The Other ◽  
Zonocerus Variegatus ◽  
Laboratory Studies ◽  
Low Levels ◽  
Relationship Of ◽  
The Relationship ◽  
Ibadan Nigeria

AbstractField and laboratory studies at Ibadan, Nigeria, showed that the young nymphs of Zonocerus variegatus (L.) normally reject cassava after biting it and die if they are confined on growing leaves. Later instars will eat cassava, especially when deprived of food for some time, but the adults progressively lose weight when restricted to feeding on growing cassava. On cut cassava, on the other hand, extensive feeding occurs and normal growth is maintained. The change from unpalatability to acceptability occurs within about an hour of cutting and is apparently associated with wilting. Cassava produces latex, but this was not distasteful to Zonocerus. The readiness to feed on growing cassava was associated with low levels of hydrogen cyanide production by the leaves; wilted leaves still produced hydrogen cyanide, but at a lower rate than turgid, growing leaves. In the area around Ibadan, Zonocerus regularly defoliates cassava in the latter part of the dry season, probably because a shortage of attractive foods forces the insect to eat cassava.

scholarly journals The Relationship Between Coronal Bright Points as Seen in He I ?10830 and the Evolution of the Photospheric Network Magnetic Fields

1985 ◽  
Vol 38 (6) ◽  
pp. 875 ◽  
Author(s):  
Karen L Harvey
Keyword(s):  
Solar Activity ◽  
Sunspot Number ◽  
Inverse Correlation ◽  
Opposite Polarity ◽  
Magnetic Polarity ◽  
The Other ◽  
Coronal Bright Points ◽  
Low Levels ◽  
The Relationship ◽  
Magnetic Network

Transient 'dark points' in He I,,10830 are found to be associated with small magnetic bipoles. The number of these dark points varies inversely with the sunspot number. Sampled over a solar cycle, about one-third of the dark points are associated with erupting magnetic flux (ephemeral regions) while the other two-thirds are associated with chance encounters of opposite magnetic polarity features. Since coronal bright points are associated with He I dark points, it is suggested that the inverse correlation of both of these events with the sunspot number results from the higher probability of chance encounters between magnetic network of opposite polarity (larger areas of mixed magnetic polarity) during low levels of solar activity.

Physical Activity and Fundamental Movement Skills of 3- to 5-Year-Old Children in Irish Preschool Services

2019 ◽  
Vol 7 (3) ◽  
pp. 354-373 ◽  
Author(s):  
Christina Duff ◽  
Johann Issartel ◽  
Wesley O’ Brien ◽  
Sarahjane Belton
Keyword(s):  
Physical Activity ◽  
Significant Relationship ◽  
Vertical Jump ◽  
Early Years ◽  
The Other ◽  
Movement Skills ◽  
Fundamental Movement Skills ◽  
Low Levels ◽  
The Relationship

The aim of this study was to quantify levels of physical activity (PA) and fundamental movement skills (FMS) of children aged 3 to 5 years in Irish preschool services during care hours, and investigate the relationship between these two variables. Data were collected from 141 children (50.3% boys, age M = 3.9 ± 0.5 years) across 9 preschool services. Measurements included PA via accelerometry, and proficiency in four FMS (run, vertical jump, throw and catch). The recommended guideline of 15 minutes of PA per hour (min PA/hour) was met by 35% of children (M = 13.6 min PA/hour). Significant differences in mean PA per hour were found by gender, with boys (14.2 min PA/hour) more active than girls (13.0 min PA/ hour), and age, with younger children (14.2 min PA/hour) more active than older (12.6 minutes PA/hour). Percentage of children proficient in the run was high (88.4%), but low across the other skills (4.9%–18.5%). Significant differences were identified by gender for vertical jump with girls scoring higher than boys. No significant relationship was found between FMS and total PA. Low levels of PA and FMS proficiency highlight need for intervention in early years settings to ensure children develop skills to participate in PA.

The effect of fibronectin and substratum-attached material on the spreading of chick embryo mesoderm cells in vitro

1980 ◽  
Vol 44 (1) ◽  
pp. 225-242
Author(s):  
E.J. Sanders
Keyword(s):  
Dorsal Surface ◽  
The Other ◽  
Plasma Fibronectin ◽  
Normal Medium ◽  
Attachment Sites ◽  
Epithelial Sheet ◽  
Low Levels ◽  
Epithelial Sheets ◽  
Scanning Electron

Endoblast and hypoblast tissue, dissected from early chick embryos, was explanted and cultured on glass or plastic substrata. These tissues grew rapidly to form epithelial sheets. Under the same conditions, mesoderm, dissected without the aid of dissociating agents, grew poorly. After 24 h in culture, the mesoderm explants consisted of a sparse outgrowth of fibroblast-like cells. When pieces of mesoderm were seeded onto the dorsal surface of the epithelia, however, the cells penetrated the sheet and rapidly spread on the substratum within 4 h. If the epithelial sheet was detached from the substratum and the mesoderm then seeded onto areas of substratum previously occupied by epithelium, similar rapid spreading occurred. This effect could be produced in the absence of serum. The method used to remove the epithelium (EDTA, detergent or manual dissection) did not influence the result. When the substratum-attached material (SAM) was examined by scanning electron microscopy, 2 types of material were seen. One type appeared to be the remains of detached filopodia and cytoplasmic lamellae, while the other appeared to be of extracellular origin. Both these types reacted positively by immunofluorescence using anti-fibronectin serum. SAM derived from mesoderm reacted negatively. When mesoderm was cultured in the presence of plasma fibronectin on unmodified plastic or glass, spreading was complete in 4–5 h and thus was similar to mesoderm seeded onto SAM. The morphology of mesoderm explants on SAM or in the presence of plasma fibronectin was more epithelial than on untreated substratum in normal medium. Hypoblast and endoblast cultured in the presence of anti-fibronectin serum failed to spread normally, apparently being unable to attach to the substratum. Mesoderm did not spread rapidly on SAM in the presence of this antiserum. Cycloheximide reversibly inhibited the spreading of hypoblast and endoblast, and this effect could be eliminated, at least for hypoblast, by the addition of plasma fibronectin. Covering attachment sites on the substratum with bovine serum albumin, thereby preventing the attachment of SAM or fibronectin, also inhibited spreading. It is proposed that mesoderm cells have low levels of surface fibronectin in comparison with endoblast and hypoblast, and that this results in a comparatively low adhesiveness, which is important for its morphogenetic activity within the embryo.

CORTICOID PRODUCTION IN VITRO AS A TEST OF ADRENOCORTICAL FUNCTION IN RATS

1960 ◽  
Vol XXXIII (I) ◽  
pp. 59-66 ◽  
Author(s):  
J. van der Vies
Keyword(s):  
Adrenal Cortex ◽  
Adrenal Function ◽  
The Other ◽  
Adrenocortical Function ◽  
Experimental Conditions ◽  
Adrenal System ◽  
Other Hand ◽  
Stimulation Of

ABSTRACT Adrenal function in rats under various experimental conditions was studied by incubating the adrenals in vitro and determining the corticosteroid output during one hour. This in vitro corticoid production was reduced after hypophysectomy, hypothalamus-lesioning and treatment with hydrocortisone or with Nembutal and morphine. On the other hand, an increased production was observed following stimulation of the pituitary-adrenal system by exogenous histamine or corticotrophin. From these experiments it is concluded that the corticoid production in vitro reflects the activity of the adrenal cortex in vivo and hence can be used for the study of the latter function.

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