Temperature shift-induced changes in the antioxidant enzyme system of Cyanobacterium synechocystis PCC 6803

• 1.1. Effect of controlled up- and down-shifts of growth temperature on the antioxidant enzymes activities and lipid peroxidation were investigated in intact cells of Cyanobacterium synechocystis PCC 6803 acclimated at different growth temperature.
• 2.2. Algal cells grown at 36°C were treated at 20 and 43°C as down- and upward-shifts of growth temperature for 24 hr, respectively. At the down-shift of growth temperature the superoxide dismutase, catalase and glutathione peroxidase were significantly increased with concomitant decrease in protein content.
• 3.3. These parameters showed similar temperature dependencies in the up-shift of growth temperature, they were decreased significantly.
• 4.4. The increased hydroxyl (HO) radical and malonyldialdehyde (MDA) formation, when algal cells exposed to down-shift of growth temperature, supposedly due to stimulated production of superoxide radicals (O₂⁻) and hydrogen peroxide (H₂O₂) at lower temperature.

     

Cumene hydroperoxide-induced chemiluminescence in human erythrocytes: Effect of antioxidants and sulfhydryl compounds

• 1.1. The time-course of cumene hydroperoxide-induced changes in lipid peroxidation, protein sulfhydryl groups and chemiluminescence intensity was determined in human erythrocytes.
• 2.2. Increase in lipid peroxidation was maximal within 60 min of incubation and was paralleled by a decrease in protein sulfhydryl groups and an increase in chemiluminescence formation.
• 3.3. A standard assay system was established to investigate the protective effects of antioxidants and scavenger compounds on cumene hydroperoxide-induced chemiluminescence formation.
• 4.4. Chain-breaking antioxidants (i.e. butylated hydroxytoluene) and sulfhydryl compounds (i.e. dithiothreitol) were able to suppress chemiluminescence formation.
• 5.5. Our results suggested that secondary free radicals, as well as sulfhydryl groups of proteins are involved in cumene hydroperoxide-induced chemiluminescence formation.

     

Superoxide dismutase,reduced glutathione and TBA-reactive products in erythrocytes of patients with multiple sclerosis

• 1.1. Superoxide dismutase, reduced glutathione and lipid peroxides levels were determined in the erythrocytes of multiple sclerosis patients.
• 2.2. Superoxide dismutase activity and the malonyldialdehyde production rate were found to be significantly enhanced.
• 3.3. The isoelectric focusing pattern of Superoxide dismutase from multiple sclerosis and normal subjects erythrocytes was substantially overlapping.
• 4.4. Our results indicate the occurrence of a higher susceptibility of multiple sclerosis erythrocytes to lipid peroxidation.

     

Collapse of K+ and ionic balance during photodynamic inactivation of leukemic cells,erythrocytes and Staphylococcus aureus

• 1.1. The immediate and fast ionic fluxes in Friend erythroleukemic cells (FELC), erythrocytes and Staphylococcus aureus during short intervals of porphyrin mediated photosensitization were determined uniquely by X-ray microanalysis (XRMA) combined with electron microscopy.
• 2.2. Photodynamic inactivation of FELC was mediated by either endogenous protoporphyrin induced by 5-amino levulinic acid (5-ALA), or Photofrin-II. We describe the predominant phenomena of >85% K-loss within 2–10 min of photoactivation. However the accompanied Na inflow and the collapse of the cellular balance of elemental-composition were inconsistent and acted as a function of cell damage.
• 3.3. Erythrocytes treated with hematoporphyrin (HP) lost most of their intracellular K yet instantly gained Na. Nevertheless the K/Na molar ratio of the control erythrocytes was nearly 12/1 while after photosensitization and K loss it changed to 1/1.
• 4.4. The S. aureus bacteria photosensitized with HP showed entire K-loss as well as marked Na efflux which increased with irradiation time; this was accompanied by the decline of other cell elements.
• 5.5. The prevailing K loss in FELC, erythrocytes and bacteria during the first minutes of photosensitization is deduced to be an immediate primary consequence of the photodynamic effect, while other ionic changes are joined in order with the development of cellular damage.

     

Biology of cave crickets,Hadenoecus subterraneus,and camel crickets,Ceuthophilus stygius (Insecta: Orthoptera): Metabolism and water economies related to size and temperature

• 1.1. Metabolic rate (MR) and water budget (WB) components of cave and camel crickets are directly related to size and temperature.
• 2.2. MR increases most rapidly with size for insects in general followed by cave crickets (females > males), and lastly, camel crickets (no sex differences).
• 3.3. Metabolic thermal sensitivity of cave crickets (males > females) is much greater than camel crickets.
• 4.4. WB components parallel MR relations.

     

A comparative study of seafish erythrocytes and agglutinins from seaweeds

• 1.1. To date, only a few authors have assayed the agglutinic activity of marine algae against fish erythrocytes, and in these cases, mainly against freshwater fish.
• 2.2. For the first time, the hemagglutinic activity of 70 seaweeds (29 brown, 37 red and four green algae) against erythrocytes of 16 seaflsh species is reported.
• 3.3. The presence of agglutinins was demonstrated in 100% of algae assayed, against at least one of the different types of erythrocytes tested.
• 4.4. The results obtained confirm the presence of receptors for algae agglutinins on the surface of the erythrocytes of the fish studied.
• 5.5. This could be useful in establishing the origins of fish populations, as these serological differences could distinguish between populations of cultivated and wild fish.

     

Ultrastructure of maturing fish (Oreochromis niloticus) and snake (Waglerophis merremii) erythroid cells with regard to hemoglobin biosynthesis

• 1.1. Fish and snake immature erythrocytes were submitted to a comparative ultrastructural study, analysing changes in organelles involved in hemoglobin (Hb) biosynthesis.
• 2.2. Iron uptake occurs probably via transferrin, and ferruginous compounds accumulate as siderosomes, taken as iron sources for heme biosynthesis, later on caught by a double lamella.
• 3.3. Mitochondrial membrane of the inner camera differentiates to lamellated bodies that, sucessively, give rise to expansions for ferruginous material and globin chains captation, constituting prehemosomal vesicles, which become condensed vesicles, followed by prohemosomes.
• 4.4. Through an internal membrane rearrangement, prohemosomes change to hemosomes wherein, hypothetically, heme and the globin chains assembly may occur.
• 5.5. In both fish and snake erythroid cells, all stages for hemosomegenesis are similar to the stages found in erythroid cells of other vertebrate species, including humans, except that fish cells often present single organelles of still unknown function, void of internal membrane.
• 6.6. Through electrophoresis of the respective supernatants obtained after osmotical lysis of the organellar fractions, it was shown that fish hemosomes contain three Hb patterns, while snake hemosomes present two patterns.

     

The taurine content of avian erythrocytes and its role in osmoregulation

• 1.1. The taurine content of erythrocytes from 15 avian species contained levels of taurine in the range of 20–70 mmol/kg of hemoglobin, about 100-fold that of mammalian red blood cells.
• 2.2. This high taurine content did not appear to be related to the nucleation of these cells as nucleated amphibian erythrocytes and human reticulocytes contained low levels.
• 3.3. The erythrocytes lacked cysteine sulfinic acid decarboxylase, a key enzyme in the synthesis of taurine from cysteine, indicating a probable lack of synthetic capabilities.
• 4.4. The cells were able to accumulate labeled taurine against a concentration gradient. This uptake was inhibited by β-alanine and was Na⁺-dependent.
• 5.5. When incubated in hypotonic medium, the cell volume of pigeon erythrocytes rapidly increased and was followed by a much slower return to normal size. The cell volume reduction was accompanied by a slow efflux of taurine into the medium.
• 6.6. These data suggest that taurine plays a role in cell volume maintenance and osmotic regulation in avian erythrocytes.

     

Studies on the nutrition of the supralittoral isopod Ligia pallasii using chemically defined artificial diets: Assessment of vitamin,carbohydrate, fatty acid,cholesterol and mineral requirements

• 1.1. An artificial diet, consisting of a dry aggregate of 59 chemical substances, was used to assess the requirements of the sea slater Ligia pallasii for vitamins, carbohydrates, fatty acids, cholesterol and minerals.
• 2.2. Good growth and survival of L. pallasii was obtained on the diet, comparable to that on seaweeds and to that shown by a field population.
• 3.3. No dietary requirements for vitamins, fatty acids or cholesterol were shown for periods of 40 weeks or more for L. pallasii.
• 4.4. Carbohydrates were shown to be required by L. pallasii in its diet, in the order: starch, lactose > maltose, glucose > sucrose, cellulose.
• 5.5. Dietary requirements for minerals were, in order: calcium, magnesium, phosphorus > copper, nickel, zinc > iron, manganese, sulphur > iodine, silicon.
• 6.6. The results are discussed in relation to the role of gut bacteria in supplying required nutrients to their isopod hosts and the enhancement of this process through coprophagic behaviour.

     

Isolation of dna and rna from Streptococcus sobrinus OMZ176 using CsTFA gradients

• 1.1. A simple procedure for isolation of high molecular weight genomic DNA, and RNA, from Streptococcus sobrinus OMZ176 is described.
• 2.2. Cell cultures were grown aerobically for 10 hr.
• 3.3. Spheroplast formation and lysis was achieved by mutanolysin/lysozyme-dependent digestion of the cell wall, followed by N-lauroylsarcosinate-mediated lysis.
• 4.4. Nucleic acids were isolated directly from cell-lysates using cesium-trifluoroacetate (CsTFA) densitygradient centrifugation.
• 5.5. Three different centrifugation regimes were tested: self-generated density gradients in a fixed angle rotor; self-generated density-gradients in a swinging-bucket rotor; pre-formed density-gradients in a swinging-bucket rotor.
• 6.6. Genomic DNA isolated by the CsTFA-procedure was found to have higher purity as compared to genomic DNA isolated in a conventional CsCl gradient.
• 7.7. Isolated DNA was shown to be of a quality suitable for applications in molecular biology.

     

Characterization of diverse hemolymph lectins in the cotton caterpillar Spodoptera littoralis

• 1.1. Hemolymph lectins (agglutinins) of the cotton caterpillar Spodoptera littoralis were analyzed by agglutination, cross-absorption and carbohydrate-hemagglutination inhibition using several vertebrate erythrocytes.
• 2.2. Lectins were found to interact, with all tested erythrocytes, by binding to carbohydrate moieties but showing no definite specificity.
• 3.3. Disulphide bonds were probably absent as 2-ME treatment was ineffective.
• 4.4. By cross-absorption studies, we have proposed that the hemolymph contains multiple lectins.

     

Acylation of lysoglycerophospholipids by adrenal membranes

• 1.1. Substantial differences were found in the acyi donor and lyso-acceptor specificities among subcellular membranes and with respect to different regions of the adrenal gland.
• 2.2. In the presence of Mg²⁺-ATP and CoASH, adrenal microsomes were actively transferring arachidonate to lysophospholipids with acyl acceptor specificity in the order: 1-acyl-GPI > 1-acyl-GPC > 1-acyl-GP. However, when oleoyl-CoA was used, acyi acceptor specificity for the microsomal transferases was in the order: 1-acyl-GPC > 1-acyl-GP > 1-acyl-GPI.
• 3.3. Mitochondrial membranes had very low acyi transfer activity and they preferred 1-acyl-GPC over other lyso-acceptors.
• 4.4. The chromamn granules were apparently lacking this type of activity.

     

Interaction of lipogenic substrates in porcine adipose tissue in vitro

• 1.1. Porcine adipose tissue was incubated with radiolabeled glucose, acetate or lactate. Saturation curves indicated that lactate > glucose > acetate in providing two-carbon units for fatty-acid synthesis.
• 2.2. Competition between individual substrates indicated that lactate was the best lipogenic substrate.
• 3.3. Incubation of all three substrates at concentrations observable in serum indicated that at 5.56mM, glucose was the preferred lipogenic substrate in the presence of 0.1 mM acetate and 1.0 mM lactate.
• 4.4. At elevated concentrations (18.52mM glucose, 1.0 mM acetate and 10.0 mM lactate), acetate and lactate were preferred to glucose as lipogenic substrates.

     

Uncovering Thousands of New Peptides with Sequence-Mask-Search Hybrid De Novo Peptide Sequencing Framework

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Highlights

• •Deep learning-based hybrid de novo sequencing with database search strategy.
• •Accurate identifications via ability to revise confidence scores and amino acids.
• •Discovery of >10,000 potential new HLA antigens and human phosphopeptides.
• •A dataset of >26 million annotated HCD spectra from Q Exactive instruments.

     

2-Deoxyglucose transport by the frog sartorius: Effects of electrical stimulation and N-carbobenzoxy-glycyl-l-phenylalaninamide

• 1.1. Studies characterizing glucose transport in the frog sartorius were performed.
• 2.2. For nonstimulated and stimulated muscles, intracellular 2-deoxyglucose exceeded 2-deoxyglucose-6-phosphate at 15 min, showed little further increase, and was maintained below the extracellular concentration for 2 hr.
• 3.3. Accumulated 2-deoxyglucose-6-phosphate did not inhibit glucose transport.
• 4.4. Unlike in adipocytes, basal and stimulated 2-deoxyglucose transport showed no difference in sensitivity to N-carbobenzoxy-glycyl-l-phenylalaninamide.
• 5.5. Phenylarsine oxide blocked contraction-enhanced 2-deoxyglucose uptake.
• 6.6. These results suggest that the glucose transporter of the sartorius exhibits auto-regulation, and that basal transport is not regulated by the same process as in adipocytes.

     

Kinetic study of the inhibition of rat liver ornithine decarboxylase by diamines; considerations on the mechanism of interaction between enzyme and inhibitor

• 1.1. Partially purified rat liver ornithine decarboxylase is inhibited by several diamines including putrescine, 1,3-diaminopropane, cadaverine and p-phenylenediamine.
• 2.2. The inhibition is dependent on pH, being strong at pH above 8 and negligible below pH 6.5.
• 3.3. The kinetic study of the inhibition showed that while the aromatic diamine behaved as a simple competitive inhibitor, the aliphatic diamines presented a more complex pattern of inhibition in which two molecules of inhibitor might bind to the enzyme active site.
• 4.4. The K_I values for the different inhibitors were calculated and the degree of affinity for the enzyme was p-phenylenediamine > putrescine > cadaverine > 1,3-diaminopropane.
• 5.5. A molecular mechanism explaining how one or two molecules of inhibitor can bind to the enzyme is proposed.

     

Effects of aluminium and pH on calcium fluxes,and effects of cadmium and manganese on calcium and sodium fluxes in brown trout (Salmo trutta L.)

• 1.1. Simultaneous measurement of calcium fluxes in brown trout, at low external [Ca] (20 μ mol 1⁻¹), provided evidence of active uptake of Ca from the medium.
• 2.2. At pH 4.5, calcium influx was inhibited and efflux was stimulated.
• 3.3. Cd and Mn, but not Al, at concentrations within the ranges found in acid waters experiencing fish population decline, inhibited calcium influx. Efflux was unaffected.
• 4.4. Cd and Mn stimulated sodium influx and efflux.

     

The effect of reduced salinity on tissue and plasma composition of the dogfish,Squalus acanthias

• 1.1. Dogfish (Squalus acanthias) were acclimated to reduced salinities and their plasma, muscle tissue and erythrocytes subsequently analysed.
• 2.2. Decrease in the osmolarity of the plasma was principally due to a fall in urea concentration and a significant fall in the concentrations of sodium and chloride.
• 3.3. Changes in the muscle and erythrocytes in dilute media were a decrease in urea, potassium, sodium and chloride concentrations.
• 4.4. The concentrations of the free amino acids in the muscle and the red blood cells decreased more than would be expected by the movements of water only.
• 5.5. The results were discussed in relation to the regulation of cellular volume and the involvement of the free amino acid pool of the tissues in this process.

     

Contrast in adenine uptake by chicken and rabbit erythrocytes in vitro

• 1.1. Relative to rabbit erythrocytes, chicken red blood cells exhibit a much greater capacity to utilize [³H]adenine for nucleotide synthesis in vitro, even at 5°C and in the absence of added inorganic phosphate.
• 2.2. This difference is largely due to a higher concentration of phosphoribosylpyrophosphate and greater activity of adenine phosphoribosyltransferase in the avian cells. lli]3. The capacity of avian erythrocytes for utilization of guanine and hypoxanthine is several fold less than that of adenine.
• 3.4. The data are consistent with lower activity for hypoxanthine/guanine phosphoribosyltransferase than for adenine phosphoribosyltransferase in intact chicken erythrocytes.
• 4.5. The results indicate that reutilization of adenine by chicken erythrocytes may be physiologically significant.

     

Effects of membrane-perturbing drugs and noradrenalin on cAMP accumulation and red cell water content in carp (Cyprinus carpio) red cells

• 1.1. Carp red cells were treated with drugs that affect the cell membranes. The water content of the cells and the accumulation of cAMP in the cells were measured in normoxia and in hypoxia using non-stimulated and adrenergically stimulated cells.
• 2.2. WGA, DIDS + CCCP and A23187 increased the water content of nonstimulated normoxic cells.
• 3.3. In hypoxia ouabain and DIDS + CCCP increased the water content but cytochalasin B, NPM, DIDS, CCCP and A23187 + CA²⁺ abolished the hypoxia-induced swelling.
• 4.4. Any membrane perturbation induced some cAMP formation, Sophora and Anquilla lectins being most potent.
• 5.5. Also in adrenergically stimulated cells, membrane perturbation generally increased cAMP formation.
• 6.6. However, cAMP accumulation diminished in cells treated with cytochalasin B, CCCP and DIDS + CCCP.
• 7.7. The adrenergic swelling of carp red cells was reduced in normoxia by DIDS. NPM and CCCP increased the adrenergic swelling in normoxia to hypoxic level.
• 8.8. In hypoxia WGA and Anquilla lectin decreased the swelling.