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  • 1
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    In:  aqdchief@seafdec.org.ph | http://aquaticcommons.org/id/eprint/18752 | 17342 | 2015-11-13 09:07:21 | 18752 | Southeast Asian Fisheries Development Center, Aquaculture Department
    Publication Date: 2021-07-11
    Description: Four chemical extenders in 7 different concentrations (potassium chloride, sodium chloride, glucose, sodium citrate, Ringer s solution, cow serum and milkfish (Chanos chanos) serum) were compared in the preservation of milkfish sperm. Results showed milkfish serum to be the most suitable of the various extenders tested. This may be attributed to suitable osmotic potential and/or presence of proteins which may have directly or indirectly influenced sperm viability. The effects of milkfish serum on the motility and fertilizing capacity of sperm at different durations of storage however need to be investigated.
    Keywords: Aquaculture ; Biology ; Chemistry ; Aquaculture ; Fish culture ; Storage ; Spermatozoa ; Chanos chanos
    Repository Name: AquaDocs
    Type: article
    Format: application/pdf
    Format: application/pdf
    Format: 1-6
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Molecular and cellular biochemistry 126 (1993), S. 1-7 
    ISSN: 1573-4919
    Keywords: Leydig cells ; testes ; superoxide dismutase ; catalase glutathione peroxidase ; glutathione ; hydrogen peroxide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Utilization of highly enriched preparations of steroidogenic Leydig cells have proven invaluable for studying the direct effects of various hormones and agents on Leydig cell functionin vitro. However, recent work indicates that isolated Leydig cells are often subjected to oxygen (O2) toxicity when cultured at ambient (19%) oxygen concentrations. Because intracellular antioxidants play an important role in protecting cells against oxygen toxicity, we have investigated the intracellular antioxidant defense system of isolated Leydig cells. The cellular levels of several antioxidants including catalase, glucose-6-phosphate dehydrogenase (G-6-PDH), superoxide dismutase (SOD) of the Cu/Zn & Mn variety, glutathione peroxidase, glutathione reductase and total glutathione were quantitated using enriched populations of Leydig cells isolated from adult male guinea pig testes. Compared to whole testicular homogenates, Leydig cells contained significantly (P〈0.01) less G-6-PDH, total SOD, glutathione reductase and total glutathione, but significantly (P〈0.001) more glutathione peroxidase. Compared to hepatic values previously reported in the guinea pig, Leydig cells contain nearly 400 times less catalase, about 14 times less glutathione peroxidase and almost 11 times less glutathione reductase. Since G-6-PDH and glutathione reductase are both necessary to regenerate reduced gluthathione (GSH) which couples with glutathione peroxidase to breakdown hydrogen peroxide (H2O2) under normal conditions, it is plausible that the oxygen toxicity observed in isolated Leydig cells is due to the intracellular accumulation of H2O2. Using the dichlorofluorescin diacetate (DCF-DA) assay, we found that Leydig cells incubated in the presence of 19% O2 produced significantly (P〈0.001) higher levels of H2O2 with time in culture compared to Leydig cells maintained at 3% O2. These results support the hypothesis that the increased susceptibility of isolated Leydig cells to oxygen toxicity may be due, in part, to decreased amounts of certain antioxidant defenses and an increased production of the reactive oxygen species H2O2.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1573-4919
    Keywords: chromium ; antioxidants ; free radical ; hydrogen peroxide ; superoxide dismutase ; catalase ; glutathione peroxidase ; glutathione reductase ; glucose-6-phosphate dehydrogenase ; ascorbate ; glutathione ; isoenzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The involvement of reactive oxygen species in chromate-induced genotoxicity has been postulated. Because intracellular antioxidants help in eliminating the reactive species of oxygen, we have investigated both the prooxidant and antioxidant status of human leukemic T-lymphocyte MOLT4 cells exposed to nontoxic levels of chromium(VI) in culture. The cells treated with 0 →200 μM potassium chromate in a salts/glucose medium for 2 h were found to contain significantly lower levels of both small molecular weight and macromolecular antioxidants. In particular, the levels of glutathione and ascorbate were found to decrease with increased doses of chromate exposure in a dose-dependent manner. As little as 10 μM chromate was found to decrease these small molecular weight antioxidants significantly (p〈0.01). The macromolecular antioxidants, such as glutathione peroxidase, catalase, glutathione reductase, glucose-6-phosphate dehydrogenase and superoxide dismutase were also significantly (p〈0.01) decreased by exposing the cells to as little as 10 μM chromate. Concomitantly there was a dose-dependent increase in intracellular H2O2 accumulation in cells exposed to chromium(VI). These results indicate that chromate-induced genotoxicity may be due, at least in part, to decreased levels of intracellular antioxidants in conjunction with an increased production of the reactive oxygen species.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Molecular and cellular biochemistry 132 (1994), S. 151-162 
    ISSN: 1573-4919
    Keywords: antiarrhythmic ; Iidocaine ; quinidine ; procainamide ; oxyradical ; free radicals ; macrophage ; phagocytosis ; respiratory burst ; flow cytometry ; hydrogen peroxide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The effect of the antiarrhythmic drugs lidocaine, quinidine and procainamide on macrophage function was investigated in RAW 264.7 mouse monocytic macrophage cell. Cells stimulated by either zymosan or phorbol ester were found to generate both superoxide (O 2 − ) and H2O2. The production of O2 was detected as superoxide dismutase inhibitable ferricytochrome c reduction. H2O2 production was monitored in both chemical and flow cytometric fluorescent assays. Although all three drugs inhibited both O2 and H2O2 release in a dose dependent manner, only quinidine was found to have significant inhibitory effects. The amounts of quinidine required to cause a 50% inhibition in O2 production in zymosan and phorbol ester stimulated cells were found to be 250 μM and 300 μM, respectively and the amounts required to cause one-half optimum levels of H2O2 production in these cells were found to be 50 μM and 100 μM, respectively. The effect of these drugs on O2 producing NADPH oxidase was investigated and only procainamide was found to have a significant effect (p〈0.001) in inhibiting the oxidase activity. Lidocaine and quinidine had no significant effect on the activation of the respiratory burst oxidase. A sensitive and convenient ‘differential phagocytosis’ assay was devised on the basis of number of particles engulfed by individual phagocytes using flow cytometric techniques. It appears to be remarkably free of interference and was applied to investigate the role of antiarrhythmic drugs on the phagocytosis of fluorescent latex beads. All three antiarrhythmic drugs inhibited phagocytosis of latex beads in a dose dependent manner irrespective of the number of particles phagocitized by the cells. The results of these studies do not conclusively establish a mechanism of action of these drugs on the generation of O2 and H2O2 by stimulated macrophages; nevertheless, it is interesting that all three drugs inhibited the phagocytic activity.
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  • 5
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The physical dimensions of several (1 → 6) branched (1 → 3) -β-D-glucan samples obtained from different organisms and their derivatives have been studied by electron microscopy, light scattering measurements, viscometry, and gel permeation chromatography. The electron micrographs indicate that in most samples these biopolymers are adequately described as linear worm-like coils. A sample reconstituted from alkaline media appeared as a blend of the linear, circular, and aggregated polymer morphologies. The average mass per unit length, ML = Mw/Lw for the macroscopically linear samples, was estimated to be 2100 ± 200 g mol-1 nm-1. The parameter mL was determined from the contour lengths obtained by electron microscopy and the molecular weight by light scattering measurements. The observed ML was consistent with the triple-helical structure reported from x-ray diffraction studies and observed degree of side-chain substitution. From the molecular snapshots shown in the electron micrographs, the persistence lengths of these β-D-glucans were determined to be 140 ± 30 nm. The experimentally determined intrinsic viscosities were consistent with these estimates of ML and persistence length. Comparison of the molecular weight distributions obtained from gel permeation chromatography and those deduced from the electron micrographs indicates that number and weight average contour lengths are more reliable than z and z + 1 averages. © 1993 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 176 (1975), S. 127-141 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Verschiedene polyfunktionelle Allylverbindungen, die 4-Oxycarbonylphthalimid-Grup-pen enthielten, wurden dargestellt, darunter N-Allyl-4-phthalimidcarbonsäure-allylester (3), die N,N′-alkylenbis(4-phthalimidcarbonsäure)-diallylester 8a-c und die Alkylenbis(N-allyl-4-phthalimidcarboxylate) 9a-e und 11.Diese Verbindungen wurden durch Erhitzen mit Dicumylperoxid oder Benzoylperoxid zu vernetzten Harzen polymerisiert, deren thermische Stabilität zunächst durch thermogravimetrische Analyse (TG) untersucht wurde. Die aus 9e und 11 hergestellten Harze zeigten unter Stickstoff bis 390 bzw. 360°C keinen Gewichtsverlust.
    Notes: Various polyfunctional allyl compounds containing 4-oxycarbonylphthalimido units were prepared including allyl N-allyl-4-phthalimidecarboxylate (3), diallyl N-N′-alky-lenebis(4-phthalimidecarboxylates) 8a-c and alkylenebis(N-allyl-4-phthalimidecarboxylates) 9a-e and 11.These compounds were polymerized by heating them in the presence of dicumyl peroxide or benzoyl peroxide to afford network resins. The thermal stability of these resins was preliminarily investigated using thermogravimetric analysis (TG). The resins from 9e and 11 had essentially no weight loss up to 390 and 360°C, respectively, in nitrogen.
    Additional Material: 2 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 177 (1976), S. 951-955 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 179 (1978), S. 1361-1364 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 14 (1970), S. 2127-2131 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 16 (1972), S. 2353-2359 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A high-density polyethylene prepared at low pressures is characterized with respect to density, microscopic examination, mechanical properties, and diffusion. The data for the slowly cooled, nonisothermally crystallized polymer clearly indicate that the method of preparation grossly affects the final properties of the polymer.
    Additional Material: 4 Ill.
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