The opacity of red cell suspension in neutral salt solution of variable concentration (non-nucleated red cell).
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Erythroblasts↗
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Cytoprotection by neutral fraction of tannat red wine against oxidative stress-induced cell death.
Some of the beneficial effects of the Mediterranean diet on human pathologies have been attributed to red wine polyphenols. It has been postulated that the antioxidant activity of the latter would be also responsible for the cytoprotective capacity of red wine that has been reported in a few papers. Nevertheless, red wine shows a complex composition, and the active fraction is not known yet. In this context, the protective capacity of total lyophilized extracts of red wine and anthocyanin, neutral, or acidic fractions, was explored in PC12 cells in culture after a hydrogen peroxide insult. Although all fractions showed high antioxidant activity, only the neutral fraction was cytoprotective. The analysis of this active fraction showed that it was rich in the aglycons quercetin and myricetin as well as the glycosides of kaempferol, isorhamnetin, epicatechin, and catechin, some of which are known to be cytoprotective. This is the first paper to reveal the active fraction of total wine responsible of its cytoprotection.
Cell Death↗
High-efficiency red electrophosphorescence based on neutral bis(pyrrole)-diimine platinum(II) complex.
Efficient red electroluminescence from the excimer or oligomer of neutral phosphorescent bis(pyrrole)-diimine Pt(II) complex has been achieved with maximum external quantum efficiency, luminous efficiency, power efficiency and brightness of 6.5%, 9.0 cd A(-1), 4.0 lm W(-1) and 11 100 cd m(-2), respectively.
Journal Article↗
Exposure of major neutral glycolipids in red cells to galactose oxidase. Effect of neuraminidase.
The exposure of several major red-cell glycolipids to galactose oxidase was studied by oxidizing the cells with the enzyme and reducing them with NaB2H4. After isolation, the deuterium label was detected by mass fragmentography. 60-70% globoside in human and porcine erythrocytes was exposed as measured by this method. In contrast, asialo-GM2 in guinea-pig erythrocytes and Forssman glycolipid in sheep erythrocytes were mainly in a cryptic state. Neuraminidase treatment increased the incorporation of deuterium label to asialo-GM2 4-8-fold. A similar effect was seen in Forssman glycolipid when sheep red cells were labeled with the neuraminidase/galactose oxidase/NaB3H4 method. In contrast, the increase in labeling was only about 10-40% in porcine and human globosides, which were efficiently exposed to galactose oxidase already in native red cells.
Animals↗
Influence of certain neutral solutes on red cell membrane area and permeability during hypotonic stress.
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Ammonium Chloride↗
Training on integrated versus separated Stroop tasks: the progression of interference and facilitation.
Two experiments examined the course of interference and facilitation in the Stroop (1935) task during training. Two versions of the task were compared: integrated (e.g., the word RED in the color green) and separated (e.g., green asterisks above the word RED). Stimuli were congruent (RED in red), incongruent (GREEN in red), or neutral (XXX in red). Over 5-day (Experiment 1) and 10-day (Experiment 2) training sessions, facilitation due to congruence was small, stable, and equivalent in both task versions. In contrast, interference declined sharply on the integrated task over Days 1-3, then slowed to parallel the gradual decline on the separated task. Finally, training on the color naming task did not affect a word reading task administered after training. These findings imply that (a) Stroop interference initially reflects two problems--overcoming integration and managing two conflicting information sources; (b) with practice, the larger integration problem is solved relatively quickly, rendering the integrated and separated tasks quite comparable thereafter; and (c) facilitation and interference in the Stroop task may be independent. These results challenge extant theories of the Stroop effect, which do not predict such effects.
Adult↗
The magnocellular visual system and schizophrenia: what can the color red tell us?
Previous research has suggested that genetic loading for schizophrenia is related to a dysfunctional magnocellular (M) subcortical visual pathway-responsible for processing movement and location. However, data substantiating this mechanism remains inconclusive. The present study used a novel technique to selectively suppress the M system in order to investigate the impact of genetic loading for schizophrenia on its functioning. A visual backward masking task was administered to 28 healthy first-degree relatives of persons with schizophrenia and 31 healthy controls. The task was administered on both a red and neutral background, as diffuse red light has been shown to selectively suppress the M system in basic vision research. On a location condition of backward masking, controls demonstrated reduced accuracy on the red compared to the neutral background. In contrast, relatives did not display differential performance between the two backgrounds. The differential effect on the two groups appears to be attributable to a difference in activity of the M pathway. Performance in the relatives was consistent with the notion of a hyperactive M pathway.
Adult↗
Prevention of rhinovirus and poliovirus uncoating by WIN 51711, a new antiviral drug.
WIN 51711, a potent new antipicornavirus drug, has been shown to inhibit an early event in the replication cycle of human poliovirus type 2 and human rhinovirus type 2. WIN 51711 was not virucidal and had no measurable effect on the adsorption of [3H]uridine-labeled virions to cells. When virion penetration of the plasma membrane was determined through loss of sensitivity to neutralizing antisera, WIN 51711 had no effect on poliovirus penetration, but inhibited rhinovirus penetration by 40%. In the presence of WIN 51711, exposure of neutral red-encapsidated virus-infected cells to light at 3 h postinfection resulted in a 3-log reduction in the number of infectious centers, indicating that WIN 51711 maintained the viral RNA in the encapsidated state after penetrating the cell membrane. The inhibition of uncoating by WIN 51711 in the neutral red assay was found to be concentration dependent, with a concentration of 0.03 micrograms/ml resulting in a 90% inhibition of uncoating. Sucrose gradient sedimentation of lysates from whole cells infected with [3H]uridine-labeled poliovirus showed that poliovirions remained intact in the presence of WIN 51711, but were uncoated in the absence of drug. WIN 51711 also prevented thermal inactivation of poliovirus infectivity, indicating a direct stabilizing effect of this compound on virion capsid conformation.
Antiviral Agents↗
Oxidative inactivation of the calcium-stimulated neutral proteinase from human red blood cells by divicine and intracellular protection by reduced glutathione.
Calpain, the micromolar Ca2+-requiring form of Ca2+-stimulated neutral proteinase purified from human red cells, is remarkably inactivated during autoxidation of divicine (2,6-diamino-4,5-dihydroxypyrimidine), an aglycone implicated in the pathogenesis of favism. Inactivation of purified calpain is produced, in decreasing order of efficiency, by transient, probably semiquinonic species arising from autoxidation of divicine, by the H2O2 that is formed upon autoxidation itself, and by quinonic divicine, respectively. Purified procalpain, the millimolar Ca2+-requiring form that can be converted to the fully active calpain form by a variety of mechanisms, is less susceptible than calpain itself to inactivation by the same by-products of divicine autoxidation. When intact red cells are exposed to autoxidizing divicine, procalpain undergoes a significant loss of activity. At 1 mM divicine, intracellular inactivation is observed with procalpain only, while the activity of a number of red cell enzymes is unaffected. Inactivation of procalpain is consistently greater in red cells from glucose-6-phosphate dehydrogenase-deficient subjects than in normal cells. Restoration of normal levels of glucose-6-phosphate dehydrogenase activity by means of entrapment of homogeneous human glucose-6-phosphate dehydrogenase in the deficient red cells results in normal stability of intracellular reduced glutathione; decreased susceptibility of procalpain to inactivation by autoxidizing divicine. These findings suggest that in the glucose-6-phosphate dehydrogenase-deficient red cells the procalpain-calpain system is a major target of divicine cytotoxicity.
Calpain↗
[The role of lipid metabolic disorders in the development of eczema and psoriasis in chronic alcoholism (clinical and experimental research)].
Blood plasma and red-cell neutral lipid spectrum and red-cell phospholipid spectrum were examined in patients with eczema and psoriasis who abused and did not abuse alcohol. Time course of these parameters was studied in guinea pigs in various periods of chronic alcoholization. Chronic alcoholization was found to be associated with manifest lipid metabolism disorders, the most characteristic shifts being evaluated membrane concentration of free cholesterol and increased level of lisophosphatidylcholin, a membranotoxic agent, as well as reduction of polyunsaturated fatty acid level in phospholipids; these factors may aggravate the course of allergic dermatoses and psoriasis.
Alcoholism↗
Seasonal variation in uptake of short-chain neutral amino acid by red blood cells and hepatocytes in trout (Salmo trutta).
The present study shows that the capacity of trout (Salmo trutta) red blood cells (RBCs) and freshly isolated hepatocytes to take up short-chain neutral amino acids changes according to a seasonal pattern. Maximal amino acid uptake rates in RBCs were obtained in winter and spring, while minima were seen in summer and autumn. In contrast, the maximal rates for the freshly isolated hepatocytes were obtained in autumn and winter, and the minima were seen in spring and summer. In addition, by studying the uptake of glycine, evidence was found that the activities of the amino acids carriers ASC, asc and Gly in RBCs varied according to a seasonal rhythm. The activity of the ASC and asc systems changed in parallel with the global uptake of amino acids. Moreover, the RBC:plasma concentration ratio for certain substrates of these carriers (alanine, serine and glycine) varied accordingly. In contrast, the activity of the Gly system was modified inversely with respect to the overall amino acid uptake. The activity of the ASC system in freshly isolated hepatocytes was also seasonally modified, reaching a maximum in autumn, shortly before the reproductive period.
Amino Acids↗
Three-dimensional scroll waves organize Dictyostelium slugs.
To test the hypothesis that periodic signals and chemotaxis direct later morphogenesis in Dictyostelium discoideum, we investigated cell behavior and cell movement in slugs. Trails of neutral red-stained prestalk and anterior-like cells were recorded by high-resolution digital image processing. Neutral red-stained anterior-like cells in the prespore zone of slugs move straight forward in the direction of slug migration and, furthermore, show coherent periodic cell movement. In contrast, cells in the prestalk zone move along completely different trajectories. Prestalk cells move perpendicular to the direction of slug migration; that is, they rotate around the tip. The cell movement data show that the chemotactic signal in the slug propagates as a three-dimensional scroll wave in the prestalk zone and as a planar wave in the prespore zone. The different behavior of prestalk and prespore cells is most likely caused by a difference in the oscillatory properties of the two cell types. We provide evidence that the slug stage of Dictyostelium behaves like an excitable system and that a (twisted) scroll wave organizes slug formation and migration.
Animals↗
Application of Nile red, a fluorescent hydrophobic probe, for the detection of neutral lipid deposits in tissue sections: comparison with oil red O.
Nile red is a phenoxazone dye that fluoresces intensely, and in varying color, in organic solvents and hydrophobic lipids. However, the fluorescence is fully quenched in water. The dye acts, therefore, as a fluorescent hydrophobic probe. We utilized this novel property of nile red to develop a sensitive fluorescent histochemical stain for tissue lipids. Nile red was prepared by boiling Nile blue A under reflux for 2 hr in 0.5% H2SO4, and extracting the product into xylene. For staining, the purified dye is dissolved in 75% glycerol (1-5 micrograms/ml) and applied to frozen tissue sections. Tissue lipids then fluoresce yellow-gold to red, depending on their relative hydrophobicity. Using sections of liver and aorta from a cholesterol-fed rabbit, we assessed the value of Nile red as a stain for neutral lipids by comparing the staining pattern obtained with that produced by oil red O, a commonly used dye for tissue cholesteryl esters and triacylglycerols. In the cholesterol fatty liver, Nile red staining was comparable to that of oil red O. In contrast, Nile red staining of rabbit aortic atheroma revealed ubiquitous lipid deposits not observed with oil red O staining. These latter results suggest that Nile red can detect neutral lipid deposits, presumably unesterified cholesterol, not usually seen with oil red O or other traditional fat stains.
Animals↗
Dynamic changes in the distribution of the calcium-activated neutral protease in human red blood cells following cellular insult and altered Ca2+ homeostasis.
Mechanistic studies were conducted to examine the relationship between oxidative membrane protein damage, altered Ca2+ homeostasis, and changes in the levels of plasma membrane-bound Ca(2+)-activated neutral protease, microCANP. Alterations in the levels of plasma membrane-bound microCANP in erythrocytes and hemolysate following cumene hydroperoxide (CHP) insult were monitored using SDS-PAGE and immunoblot analyses. Free radical scavengers, antioxidant and EGTA effects on membrane-bound microCANP levels in CHP-treated cells and hemolysate were also examined. CHP (2 mM) addition to red cells caused a significant decrease/loss in intensity of numerous protein bands in the SDS-PAGE pattern, to include bands 1, 2, 2.1, 4.1, 4.2, and an approximately 60-kDa protein. N-acetylcysteine (20 mM), dithiothreitol (50 mM), and dimethylthiourea (50 mM) diminished CHP-mediated membrane protein damage; in contrast, dimethylfuran (50 mM) exacerbated CHP-mediated membrane protein damage. Dimethylsulfoxide (50 mM) was without significant effect. The free radical scavengers and antioxidants differentially affected membrane-bound microCANP levels largely in parallel with their ability to modulate membrane protein damage. Immunoblot analysis of 1 mM CHP-treated red cells revealed a time-dependent loss of membrane-bound microCANP, with a complete loss of microCANP monitored at 8 hr. Treatment of erythrocytes with CHP also resulted in concentration-dependent alterations in the level of membrane-bound microCANP: at 0.5 or 1.0 mM CHP a decreased level of membrane-bound microCANP was detected relative to control, whereas an increase in the level of bound enzyme was monitored from 2 to 4 mM CHP. CHP addition to hemolysate produced a decrease in membrane-bound microCANP levels comparable to that observed with erythrocytes; addition of the Ca2+ chelator EGTA or Calpain Inhibitor I (N-acetyl-leucyl-leucyl-leucyl-nor-leucinal) to hemolysate effectively inhibited this decrease. In contrast, treatment of erythrocytes with Ca2+ in the presence of the Ca2+ ionophore A23187 resulted in change in the SDS-PAGE protein bands and membrane-bound microCANP levels that were comparable to those produced by CHP. Inclusion of EGTA in this system prevented microCANP binding. These data provide evidence for membrane damage and concomitant dynamic alterations in membrane-bound microCANP levels in the red cell or hemolysate following oxidative insult, and show that this process can be modulated by free radical scavengers and antioxidant, simulated by treating cells with Ca2+ in the presence of ionophore, and inhibited by EGTA or Calpain Inhibitor I.
Amino Acid Sequence↗
Differential metallothionein expression in earthworm (Lumbricus rubellus) tissues.
This article describes the immunoperoxidase localization of metallothionein (MT) in the major organs and tissues of the earthworm Lumbricus rubellus sampled from a mine soil heavily polluted with Pb, Zn, and Cd. The polyclonal antiserum used was raised against the MT isoform (wMT2), the molecular characteristics and focal subcellular distribution of which indicate a primary role for it in the sequestration of certain nonessential metals, such as Cd. Intense MT immunostaining was detectable in chloragogenous tissue throughout the body: around the intestine, in the typhlosolar infolding, around blood vessels anterior and posterior to the crop/gizzard, and around the calciferous gland. Electron probe X-ray microanalysis of neutral red-labeled vesicular structures in the chloragogenous tissue indicated that this acidic compartment, probably lysosomal, yielded the strong Cd and S signals associated with Cd-MT. MT expression was also detected in the apical cytoplasm of intestinal epithelial cells; in coelomocytes contiguous with chloragocytes attached to the gut; within the narrow tubular region of nephridia, in the secretory epithelia of the calciferous gland, but not anywhere in the body wall. We concluded that (a) the main route of Cd uptake is probably via absorptive alimentary surfaces, and not across the external epidermal layer; (b) nephridia are involved with Cd excretion and/or are a major target of Cd-induced pathological damage; (c) tentatively, a combination of immunohistochemistry and proton-induced X-ray emission analysis indicated that the calciferous gland is probably not a major "heavy metal" excretory route.
Animals↗
A comparative study of cytoplasmic granules imaged by the real-time microscope, Nile Red and Filipin in fibroblasts from patients with lipid storage diseases.
Cytoplasmic granules in fibroblasts, visualized without stains, or labelled with Nile red, Filipin, or anti-LAMP-1 (lysosome-associated membrane protein 1), were imaged using the real-time microscope (RTM). New advances in light microscope technology were applied to detect cytoplasmic granules (RTM-visible granules) and characterize them by imaging contrast, size, shape, cellular distribution, composition, motion dynamics and quantity. Appearing as solid spheroids or ring structures, the majority of the RTM-visible granules contained Nile-red labelled neutral lipids. A smaller subpopulation, appearing dimmer, with less imaging contrast, contained Filipin-labelled free cholesterol. Most lipid storage granules have a diameter ranging from 0.3 mum to 0.6 mum, with a small population measuring up to 1 mum. They typically clustered in the perinuclear region and displayed relatively small oscillatory motion. Immunofluorescence based on LAMP-1 labelling highlighted granular structures that were distinct and separate from RTM-visible granules and other structures in the light modality of the microscope. RTM-visible granules were associated with disease phenotypes that have increased cellular neutral lipid stores corresponding to the Nile red-labelled droplets (e.g. triacylglycerides, cholesterol esters). As predicted, the fibroblast strains with a defect resulting in Wolman disease, when compared to control samples, consistently had RTM-visible granules, higher in imaging contrast and with larger diameters, that were labelled with Nile red, and also an increased frequency of Filipin-cholesterol complexes. By comparison, in fibroblasts where the lipid storage is less evident (Gaucher and Farber diseases) or from GM(1) gangliosidosis, where the primary storage substances are oligosaccharides, fewer and smaller RTM-visible granules were observed. In some cases, changes in contrast and morphology in the unstained cytoplasmic compartments were more evident than in the labelled structures. In summary, applying the RTM imaging system to fibroblasts enables differences between the various disease types to be seen and, in specific examples, a unique phenotype can be readily discerned.
Antifungal Agents↗
Additional binding sites in lysozyme. X-ray analysis of lysozyme complexes with bromophenol red and bromophenol blue.
The binding sites in hen egg-white lysozyme for neutral bromophenol red (BPR) and ionized bromophenol blue (BPB) have been characterized at 2 A resolution. In either case, the dye-bound enzyme is active against the polysaccharide, but not against the cell wall. Both binding sites are outside, but close to, the hexasaccharide binding cleft in the enzyme. The binding site of BPR made up of Arg5, Lys33, Phe34, Asn37, Phe38, Ala122, Trp123 and possibly Arg125, is close to subsite F while that of BPB made up of Tyr20, Arg21, Asn93, Lys96, Lys97 and Ser100, is close to subsites A and B. The binding sites of the neutral dye and the ionized dye are thus spatially far apart. The peptide component of the bacterial cell wall probably interacts with these cells during enzyme action. Such interactions are perhaps necessary for appropriately positioning the enzyme molecule on the bacterial cell wall.
Binding Sites↗
Diurnal variations in plasma concentrations of basic and neutral amino acids and in red cell concentrations of aspartate and glutamate: effects of dietary protein intake.
The effects of dietary protein content on diurnal variations in plasma concentrations of neutral and basic amino acids, and on red blood cell levels of acidic amino acids, were studied in seven normal humans. The subjects consumed, on three consecutive 3-day periods, diets containing 0, 75, or 150 g of egg protein per day; blood was collected at 4-h intervals on the 2nd and 3rd days of each diet. For each of the large neutral amino acids (LNAA; isoleucine, leucine, tyrosine, phenylalanine, methionine, valine, and tryptophan) significant correlations were observed between its plasma levels and the protein content of the diet; highest levels were noted after consumption of the 150-g protein diet, and lowest values after the O-g protein diet. For each LNAA, except tryptophan, "fed" values (ie, those at 3 PM and 7 PM) were decreased relative to "fasting" values (those at 3 AM and 7 AM) after consumption of the O-g protein-free diet, but increased after consumption of the 150-g protein diet. Threonine, serine, and proline behaved like the LNAA: in contrast, glycine and alanine rose after protein-free meals and fell with the high-protein diet. The basic amino acids, lysine, arginine, and histidine tended to respond like the LNAA to variations in dietary protein content. Red blood cell concentrations of glutamate tended to vary inversely with the protein content of the diet, while no relationship was noted between red blood cell aspartate and dietary protein content. Food-induced changes in plasma LNAA have been found to affect brain levels of amino acids that are neurotransmitter precursors, as well as the syntheses of the transmitters themselves.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗