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41.
The whole brain free fatty acid (FFA) level, as well as the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX) were determined in the frontal cortex, cerebellum, hippocampus, and pons-medulla region of the single pentylenetetrazol (PZT)-treated and PZT-kindled Hannover-Wistar rats. PZT administration in the convulsive dose caused significant increase of the brain FFA content. Decreased SOD activity was detected in the frontal cortex of PZT-kindled rats, whereas decreased GPX activity was found in the frontal cortex and cerebellum of all treated rats, as well as in the hippocampus and pons-medulla of PZT-kindled rats. Kindling caused distinctive change of antioxidative defense in the frontal cortex, hippocampus, and pons-medulla region. 相似文献
42.
Short-term effects on consumption and oviposition rates of four strainsof Neoseiulus californicus (McGregor) after a diet shiftwere evaluated. The new feeding conditions experienced by the predators weresixfixed densities of eggs or protonymphs of Tetranychusurticae Koch placed on excised strawberry leaflet discs andmaintained under laboratory conditions (25±1°C,75–85% RH, 16L: 8D). The observations were made on the first and thefifthday of the experiment. The phytoseiids came from three long-term mass-rearedstrains fed on T. urticae, Dermatophagoides farinaeHughes,or Quercus spp. pollen, respectively. The fourth strainwascollected directly in a strawberry field. Time since diet transfer can be addedto the factors (i.e. feeding history and prey density) already known to affectthe functional and numerical responses of N. californicus,both when it feeds on prey eggs and protonymphs. If consumption rates wereaveraged over all strains and densities, 9.04 and 11.41 eggs, and 6.97 and 6.48protonymphs were consumed on the first and the fifth day, respectively. If thesame was done for oviposition rates, predators feeding on eggs produced 1.46and2.36 eggs/female/day, whereas predators feeding on protonymphs produced 1.35and2.29 eggs/female/day. Time had the greatest impact on the functional responseofthe strain that had previously fed on tetranychids, while an effect of time onthe numerical response was detectable in all strains. 相似文献
43.
Daniele Gabriel-Costa Telma Fatima da Cunha Luiz Roberto Grassmann Bechara Rodrigo Soares Fortunato Luiz Henrique Marchesi Bozi Marcele de Almeida Coelho Maria Luiza Barreto-Chaves Patricia Chakur Brum 《PloS one》2015,10(5)
Background
Besides its role as a fuel source in intermediary metabolism, lactate has been considered a signaling molecule modulating lactate-sensitive genes involved in the regulation of skeletal muscle metabolism. Even though the flux of lactate is significantly high in the heart, its role on regulation of cardiac genes regulating lactate oxidation has not been clarified yet. We tested the hypothesis that lactate would increase cardiac levels of reactive oxygen species and up-regulate the expression of genes related to lactate oxidation complex.Methods/Principal Findings
Isolated hearts from male adult Wistar rats were perfused with control, lactate or acetate (20mM) added Krebs-Henseleit solution during 120 min in modified Langendorff apparatus. Reactive oxygen species (O2 ●-/H2O2) levels, and NADH and NADPH oxidase activities (in enriched microsomal or plasmatic membranes, respectively) were evaluated by fluorimetry while SOD and catalase activities were evaluated by spectrophotometry. mRNA levels of lactate oxidation complex and energetic enzymes MCT1, MCT4, HK, LDH, PDH, CS, PGC1α and COXIV were quantified by real time RT-PCR. Mitochondrial DNA levels were also evaluated. Hemodynamic parameters were acquired during the experiment. The key findings of this work were that lactate elevated cardiac NADH oxidase activity but not NADPH activity. This response was associated with increased cardiac O2 ●-/H2O2 levels and up-regulation of MCT1, MCT4, LDH and PGC1α with no changes in HK, PDH, CS, COXIV mRNA levels and mitochondrial DNA levels. Lactate increased NRF-2 nuclear expression and SOD activity probably as counter-regulatory responses to increased O2 ●-/H2O2.Conclusions
Our results provide evidence for lactate-induced up-regulation of lactate oxidation complex associated with increased NADH oxidase activity and cardiac O2 ●-/H2O2 driving to an anti-oxidant response. These results unveil lactate as an important signaling molecule regulating components of the lactate oxidation complex in cardiac muscle. 相似文献44.
Enusha Karunasena Michael D. Larrañaga Jan S. Simoni David R. Douglas David C. Straus 《Mycopathologia》2010,170(6):377-390
Damage to human neurological system cells resulting from exposure to mycotoxins confirms a previously controversial public
health threat for occupants of water-damaged buildings. Leading scientific organizations disagree about the ability of inhaled
mycotoxins in the indoor environment to cause adverse human health effects. Damage to the neurological system can result from
exposure to trichothecene mycotoxins in the indoor environment. This study demonstrates that neurological system cell damage
can occur from satratoxin H exposure to neurological cells at exposure levels that can be found in water-damaged buildings
contaminated with fungal growth. The constant activation of inflammatory and apoptotic pathways at low levels of exposure
in human brain capillary endothelial cells, astrocytes, and neural progenitor cells may amplify devastation to neurological
tissues and lead to neurological system cell damage from indirect events triggered by the presence of trichothecenes. 相似文献
45.
Concentrations of viruses and prokaryotes in the alkaline, moderately hypersaline, seasonally stratified Mono Lake are among
the highest reported for a natural aquatic environment. We used electron microscopy to test whether viral morphological characteristics
differed among the epilimnion, metalimnion, and the anoxic hypolimnion of the lake and to determine how the properties of
viruses in Mono Lake compare to other aquatic environments. Viral capsid size distributions were more similar in the metalimnion
and hypolimnion of Mono Lake, while viral tail lengths were more similar in the epilimnion and metalimnion. The percentage
of tailed viruses decreased with depth and the relative percentages of tailed phage families changed with depth. The presence
of large (>125 nm capsid), untailed viruses in the metalimnion and hypolimnion suggests that eukaryotic viruses are produced
in these suboxic and anoxic, hypersaline environments. Capsid diameters of viruses were larger on average in Mono Lake compared
to other aquatic environments, and no lemon-shaped or filamentous viruses were found, in contrast to other high-salinity or
high-altitude lakes and seas. Our data suggest that the physically and chemically distinct layers of Mono Lake harbor different
viral assemblages, and that these assemblages are distinct from other aquatic environments that have been studied. Furthermore,
we found that filtration of a sample through a 0.22-μm pore-size filter significantly altered the distribution of viral capsid
diameters and tail lengths, resulting in a relative depletion of viruses having larger capsids and longer tails. This observation
highlights the potential for bias in molecular surveys of viral diversity, which typically rely on filtration through 0.2-
or 0.22-μm pore-size membrane filters to remove bacteria during sample preparation. 相似文献
46.
Colmenero-Flores JM Martínez G Gamba G Vázquez N Iglesias DJ Brumós J Talón M 《The Plant journal : for cell and molecular biology》2007,50(2):278-292
Chloride (Cl(-)) is an essential nutrient and one of the most abundant inorganic anions in plant tissues. We have cloned an Arabidopsis thaliana cDNA encoding for a member of the cation-Cl(-) cotransporter (CCC) family. Deduced plant CCC proteins are highly conserved, and phylogenetic analyses revealed their relationships to the sub-family of animal K(+):Cl(-) cotransporters. In Xenopus laevis oocytes, the A. thaliana CCC protein (At CCC) catalysed the co-ordinated symport of K(+), Na(+) and Cl(-), and this transport activity was inhibited by the 'loop' diuretic bumetanide, a specific inhibitor of vertebrate Na(+):K(+):Cl(-) cotransporters, indicating that At CCC encodes for a bona fide Na(+):K(+):Cl(-) cotransporter. Analysis of At CCC promoter-beta-glucuronidase transgenic Arabidopsis plants revealed preferential expression in the root and shoot vasculature at the xylem/symplast boundary, root tips, trichomes, leaf hydathodes, leaf stipules and anthers. Plants homozygous for two independent T-DNA insertions in the CCC gene exhibited shorter organs such as inflorescence stems, roots, leaves and siliques. The elongation zone of the inflorescence stem of ccc plants often necrosed during bolt emergence, while seed production was strongly impaired. In addition, ccc plants exhibited defective Cl(-) homeostasis under high salinity, as they accumulated higher and lower Cl(-) amounts in shoots and roots, respectively, than the treated wild type, suggesting At CCC involvement in long-distance Cl(-) transport. Compelling evidence is provided on the occurrence of cation-chloride cotransporters in the plant kingdom and their significant role in major plant developmental processes and Cl(-) homeostasis. 相似文献
47.
Pereira P Vinadé E Rodrigues L De David e Silva TL Ardenghi P da Silva Brum LF Gonçalves CA Izquierdo I 《Neurochemical research》2007,32(7):1150-1155
The participation of protein serine/threonine kinases in memory formation and retrieval is well established. In contrast,
relatively little is known on the role of protein tyrosine kinases (PTKs). Previous work showed that intra-hippocampal infusion
of the Src-PTK inhibitor radicicol inhibits memory acquisition, consolidation, and retrieval of one-trial step-down inhibitory avoidance
task. In this study, we investigated the possible interaction between levels of Src-PTK activity in hippocampus and memory acquisition, formation, and retrieval of this task. Radicicol (0.5 μg/ml) was infused
into the CA1 region of the hippocampus of rats trained in a one-trial step-down inhibitory avoidance task. Radicicol infused
15 min before training decreased Src-PTK activity, as measured 0, 1.5, and 24 h after training, and impaired memory acquisition of the task. When given immediately
after training, there was a decrease in Src-PTK activity 1.5 h, but not 0 or 24 h after training. This treatment depressed memory consolidation. Radicicol infused into
CA1 10 min prior to retrieval testing inhibited hippocampal Src-PTK activity, as measured immediately after the test session. The results suggest that Src-PTKs participate in memory acquisition, consolidation, and retrieval processes, but the timing of the role of the enzyme
is different in each case. 相似文献
48.
V.R. CoelhoJ. Gianesini R. Von BorowskiL. Mazzardo-Martins D.F. MartinsJ.N. Picada A.R.S. SantosL.F.S. Brum P. Pereira 《Phytomedicine》2011,18(10):896-901
It is known that (−)-linalool is a competitive antagonist of NMDA receptors, which play a key role in the learning and memory processes; however, only a few studies have reported a possible interference of (−)-linalool in memory. The purpose of this study was to investigate the (−)-linalool effects on acquisition of short- and long-term memories through the objects recognition task, inhibitory avoidance test and habituation to a novel environment. Furthermore, the open field test was used to investigate the interference of (−)-linalool in motivation, locomotion and exploration by animals. Wistar male adult rats received an intraperitoneal injection (i.p.) of saline (NaCl 0.9%), tween 5% or (−)-linalool (50 or 100 mg/kg) before training in the tasks; MK-801 (0.1 mg/kg), a glutamate antagonist, was used as positive control. Short-term (STM) and long-term (LTM) memories were tested 1.5 and 24 h after training, respectively, in the inhibitory avoidance and recognition objects. The results suggested that (−)-linalool (as 50- and 100-mg/kg doses) impaired LTM acquisition, but not STM acquisition, in the object recognition task. In the inhibitory avoidance test, animals receiving linalool (both doses) showed impairment in acquisition of both memories measured. In the open field test, the animals that received (−)-linalool showed no significant difference in the crossings and latency to start the locomotion in any of the doses tested, although (−)-linalool 100 mg/kg reduced rearing behavior. When re-exposed to open field 24 h after training, the rats that received (−)-linalool 100 mg/kg showed no habituation. Taken together, these data suggested that (−)-linalool was able to impair the acquisition of memory in rats, which can be associated to (−)-linalool antagonist capacity as regards NMDA glutamatergic receptors, since other glutamate antagonists also seem to affect memory. 相似文献
49.
Simoni D Rondanin R Marchetti P Rullo C Baruchello R Grisolia G Barbato G Giovannini R Marchioro C Capelli AM Virginio C Bozzoli A Borea PA Merighi S Donati D 《Bioorganic & medicinal chemistry letters》2011,21(18):5423-5427
The introduction of the isoxazole ring as bioisosteric replacement of the acetyl group of anatoxin-a led to a new series of derivatives binding to nicotinic acetylcholine receptors. Bulkier substitutions than methyl at the 3 position of isoxazole were shown to be detrimental for the activity. The binding potency of the most interesting compounds with α1, α7 and α3β4 receptor subtypes, was, anyway, only at micromolar level. Moreover, differently from known derivatives with pyridine, isoxazole condensed to azabicyclo ring led to no activity. 相似文献
50.
Moreira JS Almeida RG Tavares LS Santos MO Viccini LF Vasconcelos IM Oliveira JT Raposo NR Dias SC Franco OL 《The protein journal》2011,30(1):32-38
Heavy agricultural losses are closely related to attacks by insect-pests and phytopathogens such as bacteria and fungi. Among
them, the fungus Botrytis cinerea can cause gray mold in more than 200 different species of plants, and is considered a challenging problem for agribusiness.
Fungicides are commonly used to control this pathogen because they are fast-working and easy to apply. However, the continuous
use of fungicides may promote the selection of resistant fungi and can also cause profound contamination in ecosystems. Aiming
to find alternative strategies to solve these problems, several studies have focused on searching for plant proteins and peptides
with antifungal activities (AFPs). With this in mind, this report shows the isolation and characterization of two novels antifungal
proteins from flowers of rosemary pepper (Lippia sidoides Cham.) with 10 and 15 kDa. Isolation was performed by using an Octyl-Sepharose hydrophobic column. In vitro bioassays indicated
that isolated proteins were able to inhibit B. cinerea development, but were not effective against all bacteria tested. Moreover, N-termini sequences indicate that both proteins
showed sequence homology with NBS–LRR R proteins with a lower molecular mass, suggesting possible protein fragmentation. Data
reported here could help in the development of biotechnological products for crop protection against phytopathogenic fungi
in the near future. 相似文献