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241.
Figueiredo MB Castro DP S Nogueira NF Garcia ES Azambuja P 《Journal of insect physiology》2006,52(7):711-716
In this paper we investigate in vivo and in vitro effects of orally administered azadirachtin and ecdysone on the phagocytic responses of Rhodnius prolixus 5th-instar larval hemocytes to the yeast Saccharomyces cerevisiae. Groups of insects fed non-treated blood (control) and insects that received azadirachtin plus ecdysone in the blood meal were inoculated with yeast cells in the hemocele. The injected yeast cells disappeared rapidly from the hemolymph, being removed completely by 90min after inoculation. In the insects treated only with azadirachtin the clearance of free yeast circulating particles was significantly delayed compared to the two previously mentioned groups. It was demonstrated that the binding of yeast cells to hemocytes was reduced in the insects treated only with azadirachtin in comparison to both non-treated control and azadirachtin plus ecdysone-treated groups. Phagocytosis occurred when yeast cells were added to hemocyte monolayers prepared with hemolymph from blood fed insects, treated or not with azadirachtin plus ecdysone, so that yeast cells were rapidly bound to hemocytes and internalized in high numbers. By contrast, insects treated with azadirachtin exhibited a drastic reduction in the quantity of yeast cell-hemocyte binding and subsequent internalization. In all groups, the hemocytes attached to the glass slides were predominantly plasmatocytes. The magnitude and speed of the cellular response suggests that hemocyte phagocytosis is one of the main driving forces for the clearance of free circulating yeast cells from the hemolymph. We propose that ecdysone modulates phagocytosis in R. prolixus larvae, and that this effect is antagonized by azadirachtin. 相似文献
242.
R Winn J Stothert B Nadir J Hildebrandt 《Journal of applied physiology (Bethesda, Md. : 1985)》1983,55(4):1051-1056
Pressure-volume curves were obtained from excised left lungs of goats at 4, 24, and 48 h after tracheal instillation of 2.5 ml/kg of 0.1 N HCl. Air total lung capacity (TLC) at transpulmonary pressure (PL) = 35 cmH2O was 38.8 ml/kg body weight before acid, and was reduced sharply to 21.1 at 4 h, then increased to 25.6 at 24 h and 32.1 at 48 h. Excess extravascular lung water (EVLW) could account for only part of the volume reductions. Specific compliance ratio of transpulmonary pressure to total lung capacity (CL/TLC) between PL of 5 and 0 cmH2O was reduced from 0.074/cmH2O to 0.050, 0.048, and 0.053/cmH2O, respectively. Saline TLC (PL = 10 cmH2O) changed from 44.8 to 32.4, 34.3, and 45.4 ml/kg, respectively, but CL/TLC did not, suggesting airway obstruction. After injury, trapped volume at PL = 0 increased from 24.9 to 29.2, 43.3, and 37.3% TLC with air, and from 20.3 to 38.5, 33.1, and 28.5%, respectively, with saline. Air volume at a PL = 10 cmH2O on deflation fell from 82.0 to 72.1% TLC at 4 h, but was near control at 24 and 48 h. The reduction in ventilated volume was not reflected in proportionately increased shunt; therefore, some compensatory vasoconstriction must have occurred. We suggest that in affected regions increased surface forces, increased EVLW, and airway obstruction caused reductions of lung volume. 相似文献
243.
Cytoplasmic and nuclear localization sites of phosphatidylinositol 3-kinase in human osteosarcoma sensitive and multidrug-resistant Saos-2 cells 总被引:1,自引:1,他引:0
Nicoletta Zini Andrea Ognibene Alberto Bavelloni Spartaco Santi Patrizia Sabatelli Nicola Baldini Katia Scotlandi Massimo Serra Nadir Mario Maraldi 《Histochemistry and cell biology》1996,106(5):457-464
The intracellular localization of phosphatidylinositol 3-kinase (PI 3-kinase) has been analyzed by western blotting, confocal,
and electron microscopy immunocytochemistry in human osteosarcoma Saos-2 cells. By western blotting, the enzyme appears to
be present in both the cytoplasmic and nuclear subfractions. By confocal microscope immunocytochemistry, the cytoplasmic fluorescence
is localized in the perinuclear region and on a network of filaments, while a diffused signal is present in the nucleus, except
for the nucleolar areas. Ultrastructural analyses on whole cells and on in situ matrix preparations reveal that nuclear PI
3-kinase is localized in interchromatin domains, in stable association with inner nuclear matrix components, while the enzyme
diffused in the cytosol is partly associated with the cytoskeletal filaments. Quantitative evaluations indicate that, in a
multidrug-resistant variant obtained by continuous exposure of Saos-2 cells to doxorubicin, the amount of nuclear and cytoplasmic
PI 3-kinase is significantly lower than in the sensitive parental cell line. The nuclear localization of PI 3-kinase and its
variation in multidrug-resistant cells, characterized by a reduced mitotic index, are consistent with the data on the existence
of a nuclear inositol lipid cycle, which could also utilize 3-phosphorylated inositides to modulate signal transduction for
the control of some key functional activities. 相似文献
244.
Chlorhexidine (0.5-0.65 microM) and Triton X45 (30-40 microM) added to exponential phase Bacillus megaterium KM- cultures was growth inhibitory. The presence of KCl (0.05-0.35 M) in the medium did not significantly affect growth rate in the absence of drug, yet reduced the growth inhibitory activity of the chlorhexidine and enhanced that of Triton X45. These effects were maximal at KCl concentrations of 0.2 M and above, when complete protection towards chlorhexidine and lysis of the cultures in the presence of Triton X45 were observed. Time-survivor curves in the presence of chlorhexidine (0.7-1.0 microM) gave LT90 values of 1.5-2.0 h in the absence of KCl, yet its inclusion (0.35 M) totally inhibited this low level bactericidal activity. Drug absorption by whole cell and isolated cell wall preparations was determined in the presence and absence of KCl (0.35 M). Chlorhexidine uptake by intact cells was reduced by approximately 50% in the presence of salt whereas that of Triton X45 increased by a similar fraction. Uptake of chlorhexidine by the cell wall fraction accounted for approximately 50% of that for the whole cells and was relatively unaffected by the presence of KCl. Conversely, absorption of Triton X45 by the cell wall fraction accounted for most of the uptake by whole cells and increased markedly in the presence of salts. 相似文献
245.
Gildene Alves da Costa Dilina do Nascimento Marreiro Juliana Maria Libório Eulálio José Machado Moita Neto Amanda Castro Amorim Apolônia Maria Tavares Nogueira Semíramis Jamil Hadad do Monte Nadir do Nascimento Nogueira 《Biological trace element research》2008,126(1):15
This study evaluated nutritional status linked to zinc levels in 239 randomly selected children at crèches in Teresina, Brazil, aged 3 to 6. Blood samples were collected after fasting of 10 h. Erythrocytary zinc levels were determined through flame atomic absorption spectrophotometry. Zinc deficiency was determined as below 40 µg Zn/g Hb. Infant linear growth was evaluated measuring weight and height, and nutritional status by height/age, weight/height, and weight/age indices, expressed as Z scores, in line with the National Center for Health Statistics. The mean zinc concentration was 35.50?±?10.95 µg Zn/g Hb. Zinc distribution in the 10, 50, 75, and 90 percentiles was 24.73 µg Zn/g Hb, 35.45 µg Zn/g Hb, 40.73 µg Zn/g Hb and 52.77 µg Zn/g Hb, respectively. Based on this distribution, normal values were found only from the 75th percentile and above. Since the cutoff point adopted was 40 µg Zn/g Hb, the prevalence of zinc deficiency was 74.3%. As for growth profile, 8.4% were chronically malnourished, although the statistical association between linear impairment and nutritional status regarding zinc was insignificant. The study revealed that an important segment of the infant population was mineral deficient; however, the degree of deficiency did not influence growth profiles. 相似文献
246.
Nadia Zayed Xinfang Li Nadir Chabane Mohamed Benderdour Johanne Martel-Pelletier Jean-Pierre Pelletier Nicolas Duval Hassan Fahmi 《Arthritis research & therapy》2008,10(6):R146
Introduction
Prostaglandin D synthase (PGDS) is responsible for the biosynthesis of PGD and J series, which have been shown to exhibit anti-inflammatory and anticatabolic effects. Two isoforms have been identified: hematopoietic- and lipocalin-type PGDS (H-PGDS and L-PGDS, respectively). The aims of this study were to investigate the expressions of H-PGDS and L-PGDS in cartilage from healthy donors and from patients with osteoarthritis (OA) and to characterize their regulation by interleukin-1-beta (IL-1β) in cultured OA chondrocytes. 相似文献247.
Studies were conducted to evaluate potential impacts of generalist predators on the biological control of Glycaspis brimblecombei Moore (Homoptera: Psylloidea), a pest of eucalyptus trees in California, and its introduced parasitoid Psyllaephagus bliteus (Hymenoptera: Encyrtidae). Based on the results of the monitoring populations of G. brimblecombei and their natural enemies in inland and coastal California in the field, P. bliteus or Anthocoris nemoralis (Fabricius) (Heteroptera: Anthocoridae), alone or both species together were released into cages with G. brimblecombei to simulate predatory interference on the introduced parasitoid in the laboratory. Although coastal sites had higher densities of natural enemies as were percent parasitism and predation, the mean number of G. brimblecombei did not vary between inland and coastal sites. P. bliteus or A. nemoralis significantly reduced the psyllid densities in cages. However, when both species were together, the presence of A. nemoralis increased the parasitoid mortality relative to the mortality observed in the parasitoid-alone treatment. Moreover, the increase in parasitoid mortality was followed by the decrease in mortality of the psyllids. The current study also indicated that predation risk of parasitized hosts varies depending on the developmental stages of the psyllids. 相似文献
248.
Violaine Jourdie Nadir Alvarez Ted C. J. Turlings 《Agricultural and Forest Entomology》2008,10(2):129-136
1 The fall armyworm Spodoptera frugiperda is a voracious pest of numerous crops of economic importance throughout the New World. In its native Mexico, larvae can be attacked by several species of parasitic wasps, which are candidate biological control agents against this and other lepidopteran pests. 2 We attempted to survey the parasitoid fauna on S. frugiperda in maize and sorghum fields throughout Mexico. However, our efforts have been hampered by the incomplete development of parasitoid larvae emerging from collected Spodoptera caterpillars. 3 This problem was solved by developing a method to identify seven species of parasitic wasps using polymerase chain reaction amplification and restriction enzyme digestion. This enables the precise determination of the species of those parasitoid larvae that are usually not morphologically identifiable. 相似文献
249.
Maraldi NM Squarzoni S Sabatelli P Capanni C Mattioli E Ognibene A Lattanzi G 《Journal of cellular physiology》2005,203(2):319-327
Just at the beginning of the millennium the neologism laminopathies has been introduced in the scientific vocabulary. An exponential increase of interest on the subject started concomitantly, so that a formerly quite neglected group of rare human diseases is now widely investigated. This review will cover the history of the identification of the molecular basis for fourteen (since now) hereditary diseases arising from defects in genes that encode nuclear envelope and nuclear lamina-associated proteins and will also consider the hypotheses that can account for the role of structural nuclear proteins in the pathogenesis of diseases affecting a wide spectrum of tissues. 相似文献
250.