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1.
Influence of prey species and stages on predatory efficiency and development of two phytoseiid mites
The effect of prey species and the different stages of prey on the predatory efficiency and biology of the phytoseiid mites,Amblyseius gossipi
Elbadry andTyphlodromus mangiferus sp. n. was studied. It was found that feeding either predator onTetranychus cucurbitacearum (Sayed) promoted faster development and a higher rate of oviposition than rearing on the twospotted spider mite,T. urticae (Koch). Different stages of both prey species also produced different responses in the biological activities of these predaceous
mites.
Résumé On a étudié l'effet de l'espèce de la proie et de ses différents stades sur l'efficacité et la biologie des acariens phytoseiides,Amblyseius gossipi Elbadry etTyphlodromus mangiferus sp. n. Il a été constaté que l'alimentation des 2 prédateurs avecTetranychus cucurbitacearus (Sayed) assure un dévelopment plus rapide et une fécondité plus élevée que leur élevage surT. urticae (Koch). Les différents stades de ces 2 proies produisent des réponses différentes dans les activités biologiques des 2 acariens prédateurs.相似文献
2.
A single dose of zearalenone (10 g/g LBW) was injected intraperitoneally to Wistar Albino rats at the age of 50–100 days. The uterine acetyl cholinesterase enzyme was significantly increased in the treated animals compared to that in the controls. Therefore, zearalenone would be considered as an esterogenic effector for increasing the uterine acetyl cholinesterase which enhances uterine relaxation and subsequently improves its function for pregnancy in prematured-animals.Unlike estradiol, it was interesting to find that the estrogenicity of zearalenone was increased by the moderating progesterone hormone. Moreover, it was revealed in this study that the injected dose of zearalenone had no deleterious effects on the pregnant rats at 10–12 days period of gestation. The harmful effects of zearalenone on pregnant animals cited in the literature (11, 13, 19) were reviewed. 相似文献
3.
Synopsis Bagrids in Bahr Shebeen Nilotic canal depend mainly on fish, insects and shrimp as well as fish embryos for food and their stomachs included runoff materials (e.g. plant foliage, glass, black crystals, coloured gravel). B. bayad maximised its efficiency of catching prey catfish by face to face attack to avoid damage by the prey's pectoral and dorsal spines. In the size classes of 10 to 30 cm standard length, B. bayad and B. docmac show diet overlap and interact with each other especially with respect to tilapias as prey. After this length, B. docmac, aided by its relatively larger mouth, shifted to larger size of tilapias to coexist with B. bayad. 相似文献
4.
Nabil Elsayed Allen Hacker Mohammad Mustafa Klaus Kuehn Gerhard Schrauzer 《Biochemical and biophysical research communications》1982,104(2):564-569
The effects of reducing glutathione peroxidase activity in the lung by changing dietary selenium intake has been investigated. In animals that were exposed to room air, selenium effects were confined to glutathione peroxidase activity, whereas under conditions of oxidant stress (ozone) the decrease in glutathione peroxidase activity prevented the stimulation of the pentose phosphate cycle (assayed by measuring glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activities) which has been reported to increase in response to oxidant stress. The suppression of glutathione peroxidase activity was found to depend on dietary selenium concentration. The physiological significance of this observation may be related to the process of injury and repair in the lung. 相似文献
5.
Elsayed A. M. Abdallah David A. Jett Mohyee E. Eldefrawi Amira T. Eldefrawi 《Journal of biochemical and molecular toxicology》1992,7(2):125-132
The effects of the organophosphorus anticholinesterase paraoxon on the binding of radioactive ligands to the M3 subtype of the muscarinic receptor and receptor-coupled synthesis of second messengers in intact rat submaxillary gland (SMG) cells were investigated. The binding of [3H]quinuclidinyl benzilate ([3H]QNB) was most sensitive to atropine and the M3-specific antagonist 4-DAMP followed by pirenzepine and least sensitive to the cardioselective M2 antagonist AFDX116. This, and the binding characteristics of [3H]4-DAMP, confirmed that the muscarinic receptors in this preparation are of the M3 subtype. Activation of these muscarinic receptors by carbamylcholine (CBC) produced both stimulation of phosphoinositide (PI) hydrolysis and inhibition of cAMP synthesis, suggesting that this receptor subtype couples to both effector systems. Paraoxon (100 μM) reduced Bmax of [3H]4-DAMP binding from 27 ± 4 to 13 ± 3 fmol/mg protein with nonsignificant change in affinity, suggesting noncompetitive inhibition of binding by paraoxon. Like the agonist CBC, paraoxon inhibited the forskolininduced cAMP formation in SMG cells with an EC50 of 200 nM, but paraoxon was > 500 fold more potent than CBC. However, while the inhibition by CBC was counteracted by 2 μM atropine, that by paraoxon was unaffected by up to 100 μM atropine. It suggested that this effect of paraoxon was not via binding to the muscarinic receptor. Paraoxon did not affect β-adrenoreceptor function in the preparation, since it did not affect the 10 μM isoproterenol-induced cAMP synthesis, which was inhibited totally by 10 μM propranolol and partially by CBC. Paraoxon had a small but significant effect on CBC-stimulated PI metabolism in the SMG cells. It is suggested that paraoxon binds to two different sites in these SMG cells. One is an allosteric site on the M3 muscarinic receptor which affects ligand binding and may modulate receptor function. The other site may be on the Gi proteinadenylyl cyclase system, and produces CBC-like action, that is, inhibition of the forskolin-stimulated [3H]cAMP synthesis, and is unaffected by atropine inhibition of the muscarinic receptor. This adds to the complexity of paraoxon actions on muscarinic receptors and their effector systems. 相似文献
6.
Automated assays for superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activity 总被引:18,自引:0,他引:18
C R Wheeler J A Salzman N M Elsayed S T Omaye D W Korte 《Analytical biochemistry》1990,184(2):193-199
Automated assays for catalase, glutathione peroxidase, glutathione reductase, and superoxide dismutase are presented. The assay for catalase is based on the peroxidatic activity of the enzyme. The glutathione peroxidase and reductase assays measure the consumption of NADPH following the reduction of t-butyl hydroperoxide and oxidized glutathione, respectively. The assay for superoxide dismutase is based on the reduction of cytochrome c. All assays utilize the Cobas FARA clinical automated analyzer and provide considerable time savings over the manual assays. 相似文献
7.
Serial concentrations of aflatoxin B1 ranging from 200 to 1500 p.p.b. in 2% lactic acid solution (which is the aimed concentration of lactic acid in fresh silage) were assayed for detoxification. Thin-layer chromatography analysis, revealed a complete transformation of 1 000 p.p.b. of aflatoxin B1 to a new fluorescing compount corresponding to aflatoxin B2a which is referred to as hydroxydihydro-aflatoxin B1 toxicity test on chickens confirmed Ciegler's findings (4). The results confirm that the chemical changes taken place in the silo can detoxify aflatoxin B1 to aflatoxin B2a. 相似文献
8.
9.
G F David E S Hafez M A Kamash 《Folia primatologica; international journal of primatology》1975,23(1-2):124-134
Cytological characteristics and pattern of distribution of different cell types in the epithelia of cervix and uterus of crab-eating macaque (Macaca fascicularis) in follicular and luteal phases of the menstrual cyclic and amenorrhea were studied. The cervix uteri and uterus exhibit remarkable structural differenes in the ciliated, secretory, and ciliated-secretory cells. Since the number of ciliated-sexretory cells in the uterus is higher than in the cervix. It is believed that they form an additional source for the secretion of uterine fluid during the menstrual cylce. Both ciliated and secretory cells undergo degeneration; extensive cytoplasmic vacuolation associated with pycnosis and disorganization of the nuclei encountered. 相似文献
10.
This work was conducted in order to study the kinetic behaviour of dietary aflatoxins in the colostrum of a pregnant cow exposed to contaminated feeds for a short period.In this study, two pregnant cows received a single dose of dietary aflatoxins in the form of rice powder contained 31.20 ppm aflatoxin B and 19.68 ppm aflatoxin G during the last stage of pregnancy, at about two weeks before parturition.Samples of colostrum were collected from dams and assayed for the presence of toxic metabolites as well as its conjugations by electrophoretic analysis.The results revealed that the intake of aflatoxins appeared in the colostrum pospartum as AFM1 and also AFB2a which is a non toxic metabolite. Moreover, it was found that the excreted metabolites including AFB2a were conjugated to the immunoglobulin protein fraction of the colostrum.The significance of the obtained results to the newborn calf are discussed. 相似文献