共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Vinícius Stone Pauline M. August Daniela P. Stocher Caroline P. Klein Pablo R. G. Couto Yasmini D. Silva 《Free radical research》2016,50(5):530-541
Dietary restriction increases life span and protects distinct organisms against a series of diseases, among which, those related to oxidative stress, like neurodegenerative diseases. Interferences in the maternal environment are known to reprogram the offspring metabolism response, impacting in the risk of chronic diseases development in adulthood. We aimed to assess the effects of 40% food restriction on reactive species levels, enzymatic and non-enzymatic antioxidant defenses, and oxidative damage parameters in the cerebellum and total cerebral cortex of pregnant rats and their offspring. Dams and pups showed oxidative modulation caused by food restriction in both structures. Dichlorofluorescein oxidation, reflecting reactive species levels, was reduced in the cerebellum of dams and offspring, while the cerebral cortex was not affected. Decreased mitochondrial superoxide levels were found in the cerebellum and cerebral cortex of pups, while nitric oxide was increased in the cortex. We also measured the activities of important antioxidant enzymes responsible by reactive oxygen species elimination. Superoxide dismutase activity was increased in the cerebellum of dams and in both structures of pups, while it was decreased in dams’ cerebral cortex. Both brain structures were affected concerning to catalase, glutathione peroxidase, and glutaredoxin activities, which were reduced in pups and dams. Non-enzymatic defenses were decreased in pups, while dams showed an adaptive pattern in the cerebellum and no alteration in the cerebral cortex. Even though the results suggest increased oxidative status, lipids and proteins were not oxidatively affected. Our data suggest that intrauterine food restriction may disrupt oxidative status, impairing the antioxidant network. 相似文献
3.
Maltotriose is metabolized by baker’s and brewer’s yeast only oxidatively, with a respiratory quotient of 1.0, the
being, depending on the strain used, 0–11, as compared with
of 6–42μL CO2 per h per mg dry substance. The transport appeared to proceed by facilitated diffusion (no effects of NaF, iodoacetamide
and 3-chlorophenylhydrazonomalononitrile) with a KT of more than 50mm and was inhibited by maltose > maltotriose > methyl-α-D-glucoside > maltotetraose >D-fruetose >D-glucose. The transport was present constitutively in bothSaccharomyces cerevisiae (baker’s yeast) and inS. uvarum (brewer’s yeast) and it was not significantly stimulated by preincubation with glucose or maltose. The pH optimum was 4.5–5.5,
the temperature dependence yielded an activation energy of 26 kJ/mol. 相似文献
4.
5.
Chasing genes in Alzheimer’s and Parkinson’s disease 总被引:4,自引:0,他引:4
Alzheimers disease (AD), the most common type of dementia, and Parkinsons disease (PD), the most common movement disorder, are both neurodegenerative adult-onset diseases characterized by the progressive loss of specific neuronal populations and the accumulation of intraneuronal inclusions. The search for genetic and environmental factors that determine the fate of neurons during the ageing process has been a widespread approach in the battle against neurodegenerative disorders. Genetic studies of AD and PD initially focused on the search for genes involved in the aetiological mechanisms of monogenic forms of these diseases. They later expanded to study hundreds of patients, affected relative-pairs and population-based studies, sometimes performed on special isolated populations. A growing number of genes (and pathogenic mutations) is being identified that cause or increase susceptibility to AD and PD. This review discusses the way in which strategies of gene hunting have evolved during the last few years and the significance of finding genes such as the presenilins, -synuclein, parkin and DJ-1. In addition, we discuss possible links between these two neurodegenerative disorders. The clinical, pathological and genetic presentation of AD and PD suggests the involvement of a few overlapping interrelated pathways. Their imbricate features point to a spectrum of neurodegeneration (tauopathies, synucleinopathies, amyloidopathies) that need further intense investigation to find the missing links. 相似文献
6.
We extend the game theoretic model of kleptoparasitism discussed in Broom et al. (2004), by considering a population of foragers
consisting of two groups with different behaviours—those who forage and steal from other feeders, and those who only forage.
We a sume that those who do not steal have a better foraging rate than those who are also looking out for opportunities to
steal. We also allow either type to resist an attack or not resist. We look for Evolutionary Stable States, of either a mixture
of the two behaviours, or where the whole population has just one of these behaviours. We find nine such ESS’s, dependent
on the environmental parameters, although in fact only five of these are distinguishable. In general, we find that if the
overall population density is low, food-stealing becomes less viable, and there is an ESS consisting of only foragers. Conversely,
when there are many animals looking for, and finding, food, there is an ESS consisting of just kleptoparasites (which are
also foraging). In between, an ESS will contain both pure-foragers and stealers. There is some empirical evidence of such
behaviours.
We find that when there is a mixture of the two types, they must both have the same resistive behaviour. We can thus have
some individuals challenging for food but not resisting challenges, and others not challenging and not resisting. This shows
how aggressive behaviour may be context-dependent, as seen in practice. 相似文献
7.
Joshua Rosenau 《Evolution》2012,5(4):582-584
Exploring life??s diversity and geography??s effect on it was central to Darwin and Wallace??s parallel discoveries of evolution. Those discoveries required the two to overcome their own misconceptions about species and biology. By helping students to see the world through the eyes of explorers and placing life??s diversity into a geographic context, teachers can help students overcome those same barriers to the acceptance of evolution and deepen students?? appreciation of biodiversity. 相似文献
8.
Phosphorus in sediments — speciation and analysis 总被引:3,自引:0,他引:3
Characterization of sediment phosphorus is commonly based on sequential chemical extractions, in which phosphorus is supposed to be selectively removed from different compounds in the sediments. The first extraction schemes were designed to quantify discrete chemical or mineralogical compounds. As extraction schemes have been tested on different sediments, several systematic errors have been detected and the schemes have been modified and simplified accordingly. Other chemical extractions or treatments have attempted to determine phosphorus bound to particles with a certain strength or binding energy, the purpose being to determine the labile, loosely bound, exchangeable, mobile or algal-available fraction of sediment phosphorus. All extraction procedures yield operationally defined fractions and cannot be used for identification of discrete phosphorus compounds. The many methodological modifications make it necessary to be cautious when comparing results from the literature in this field. 相似文献
9.
A. S. Gorina L. S. Kolesnichenko V. I. Mikhnovich 《Biochemistry (Moscow) Supplemental Series B: Biomedical Chemistry》2011,5(4):397-401
In a stable state children with Asperger’s and Kanner’s syndromes demonstrate a similar decrease in plasma norepinephrine.
In the aggravated state, these changes become more expressed and are characterized by a decrease in plasma tyrosine, norepinephrine,
normetanephrine, and by an increase in dopamine and homovanillic acid and a decrease in excretion of norepinephrine and an
increase in excretion of homovanillic acid, epinephrine and 3-methoxy-4-hydroxyphenylglycol (MHPG). In the aggravated state
children with Kanner’s syndrome were characterized by increased plasma MHPG, decreased excretion of tyrosine and increased
expression of normetanephrine. The observed imbalance in dopamine and epinephrine/norepinephrine systems suggests importance
of combined analysis of changes in catecholamines and their metabolites as the most informative approach in the study of the
effect of autistic disorders. 相似文献
10.
Rebecca Bliege Bird Brian F. Codding Douglas W. Bird 《Human nature (Hawthorne, N.Y.)》2009,20(2):105-129
Researchers commonly use long-term average production inequalities to characterize cross-cultural patterns in foraging divisions
of labor, but little is known about how the strategies of individuals shape such inequalities. Here, we explore the factors
that lead to daily variation in how much men produce relative to women among Martu, contemporary foragers of the Western Desert
of Australia. We analyze variation in foraging decisions on temporary foraging camps and find that the percentage of total
camp production provided by each gender varies primarily as a function of men’s average bout successes with large, mobile
prey. When men target large prey, either their success leads to a large proportional contribution to the daily harvest, or
their failure results in no contribution. When both men and women target small reliable prey, production inequalities by gender
are minimized. These results suggest that production inequalities among Martu emerge from stochastic variation in men’s foraging
success on large prey measured against the backdrop of women’s consistent production of small, low-variance resources.
Rebecca Bliege Bird received her Ph.D. from UC Davis in 1996. She is interested in gendered strategies of social and economic production, especially as they relate to altruism and public goods provisioning in prestige competitions. In pursuit of these and other questions related to the socioecology of subsistence, she has worked in Torres Strait among the Meriam and is currently working with Martu in Australia’s Western Desert. Brian F. Codding received his B.S. from California Polytechnic State University, San Luis Obispo in 2005 and his M.A. in 2008 from Stanford University, where he is currently a Ph.D. student in the Department of Anthropology. His current research examines the social ecology of gender-specific foraging in archaeological and ethnographic contexts in California and Western Australia. Douglas W. Bird received his Ph.D. from UC Davis in 1996. His interest in ethnoarchaeology led him to explore the processes of shellmidden formation among Meriam of the Torres Strait. He is currently investigating the politics of hunting among Martu and the way that sharing can, paradoxically, create social hierarchy. 相似文献
Douglas W. BirdEmail: |
Rebecca Bliege Bird received her Ph.D. from UC Davis in 1996. She is interested in gendered strategies of social and economic production, especially as they relate to altruism and public goods provisioning in prestige competitions. In pursuit of these and other questions related to the socioecology of subsistence, she has worked in Torres Strait among the Meriam and is currently working with Martu in Australia’s Western Desert. Brian F. Codding received his B.S. from California Polytechnic State University, San Luis Obispo in 2005 and his M.A. in 2008 from Stanford University, where he is currently a Ph.D. student in the Department of Anthropology. His current research examines the social ecology of gender-specific foraging in archaeological and ethnographic contexts in California and Western Australia. Douglas W. Bird received his Ph.D. from UC Davis in 1996. His interest in ethnoarchaeology led him to explore the processes of shellmidden formation among Meriam of the Torres Strait. He is currently investigating the politics of hunting among Martu and the way that sharing can, paradoxically, create social hierarchy. 相似文献
11.
12.
Metalloproteinase’s Activity and Oxidative Stress in Mild Cognitive Impairment and Alzheimer’s Disease 总被引:1,自引:0,他引:1
Martín-Aragón S Bermejo-Bescós P Benedí J Felici E Gil P Ribera JM Villar AM 《Neurochemical research》2009,34(2):373-378
Matrix metalloproteinases (MMPs) and oxidative stress have been implicated in neurological diseases such as Alzheimer’s disease
(AD). Plasma MMP-2 and MMP-9 activities were assessed in Mild Cognitive Impairment (MCI) and AD subjects compared with aged-matched
controls, and subsequently analysed in relation to oxidative stress markers. Both MMP-2 and MMP-9 showed no significant changes
versus control subjects. Plasma glutathione peroxidase Se-dependent (GPx-Se) activity and malondialdehyde (MDA) levels were
higher in AD than in controls (P < 0.05), suggesting a role for GPx-Se in controlling oxidative stress in AD. Negative correlations were observed between MMPs
and MDA in AD and MCI patients (P < 0.05). In conclusion, oxidative stress events did not include activation of MMPs and this similar pattern in AD and MCI
suggests that both are biochemically equivalent. 相似文献
13.
Haruyo Nakajima-Adachi Akira Kikuchi Yoko Fujimura Kyoko Shibahara Tsuyoshi Makino Masae Goseki-Sone Miran Kihara-Fujioka Tomonori Nochi Yosuke Kurashima Osamu Igarashi Masafumi Yamamoto Jun Kunisawa Masako Toda Shuichi Kaminogawa Ryuichiro Sato Hiroshi Kiyono Satoshi Hachimura 《PloS one》2014,9(10)
Background and Objective
To improve the efficacy and safety of tolerance induction for food allergies, identifying the tissues responsible for inducing intestinal inflammation and subsequent oral tolerance is important. We used OVA23-3 mice, which express an ovalbumin-specific T-cell receptor, to elucidate the roles of local and systemic immune tissues in intestinal inflammation.Methods and Results
OVA23-3 mice developed marked enteropathy after consuming a diet containing egg white (EW diet) for 10 days but overcame the enteropathy (despite continued moderate inflammation) after receiving EW diet for a total of 28 days. Injecting mice with anti-IL-4 antibody or cyclosporine A confirmed the involvement of Th2 cells in the development of the enteropathy. To assess the individual contributions of Peyer’s patches (PPs), mesenteric lymph nodes (MLNs), and the spleen to the generation of effector CD4+ T-cells, we analyzed the IL-4 production, proliferation in response to ovalbumin, and CD4+ T-cell numbers of these tissues. EW feeding for 10 days induced significant IL-4 production in PPs, the infiltration of numerous CD4+ T-cells into MLNs, and a decrease in CD4+ T-cell numbers in spleen. On day 28, CD4+ T-cells from all tissues had attenuated responses to ovalbumin, suggesting tolerance acquisition, although MLN CD4+ T-cells still maintained IL-4 production with proliferation. In addition, removal of MLNs but not the spleen decreased the severity of enteropathy and PP-disrupted mice showed delayed onset of EW-induced inflammatory responses. Disruption of peripheral lymphoid tissues or of both PPs and MLNs almost completely prevented the enteropathy.Conclusions
PPs and MLNs coordinately promote enteropathy by generating effector T-cells during the initial and exacerbated phases, respectively; the spleen is dispensable for enteropathy and shows tolerogenic responses throughout EW-feeding. The regulation of PPs may suppress the initiation of intestinal inflammation, subsequently restricting MLNs and inhibiting the progression of food-allergic enteropathy. 相似文献14.
One of the main functions of exploratory behaviour is to gain information about the environment. The adaptive value of such behaviour should vary with ecological conditions influencing the diversity and stability of resources, as well as with the costs associated with gathering information. Consequently, predictions can be made about environmental factors influencing the evolution of exploration. We used comparative methods, combining a field experiment with literature data, to study correlated evolution between explorative behaviour and ecology among 13 species of Darwin’s finches. Controlling for phylogenetic influences, we found that exploration (measured as the proportion of individuals responding in the experiment) increased with diet diversity and the amount of fruit in diet, consistent with theories stating that exploration aimed at finding new food types should be more beneficial for generalists than for specialists. However, our study is the first to demonstrate a correlation between neophilia and food diversity. Contrary to our prediction, species with a high percentage of concealed food in their diet were less explorative. A possible explanation for this novel finding is that in our study system concealed food may be a stable resource, and species using such resources should be less dependent on the discovery of new food types. 相似文献
15.
Hüseyin Ambarlı 《Anthrozo?s》2016,29(3):489-502
Many studies have examined adults’ perceptions of and attitudes toward large carnivores to assess human–wildlife conflict and inform conservation strategies, but there have been few studies concerning children. I studied secondary school students’ perceptions of and attitudes toward brown bears (Ursus arctos) and other large mammals in Turkey via a questionnaire survey. The questionnaire, consisting of 18 questions, was completed by 215 rural and 98 urban secondary school students. Both sets of students liked bears; they were also afraid of them and unsure about living with them in the future. While there were no gender differences in attitudes and perceptions, there were marked differences between urban and rural students. Urban students had less contact with nature, gained more of their knowledge about bears from documentaries, and had less positive attitudes toward bears. They were also more likely to be afraid of species not present in Turkey, for example, anaconda, while rural students were most afraid of wild boars. Factor analysis identified three important themes: familiarity with bears, conservation of bears, and experiencing conflict with bears, which explained 49.8% of the variance in attitudes toward bears. The most important factor for the development of negative attitudes toward bears was personal experience of human–bear conflict, suggesting that measures to reduce human–bear conflict in rural areas may help to sustain students’ positive attitudes toward the conservation of bears. 相似文献
16.
Wilson’s disease (WD) is a severe disorder of copper misbalance, which manifests with a wide spectrum of liver pathology and/or
neurologic and psychiatric symptoms. WD is caused by mutations in a gene encoding a copper-transporting ATPase ATP7B and is
accompanied by accumulation of copper in tissues, especially in the liver. Copper-chelation therapy is available for treatment
of WD symptoms and is often successful, however, significant challenges remain with respect to timely diagnostics and treatment
of the disease. The lack of genotype-phenotype correlation remains unexplained, the causes of fulminant liver failure are
not known, and the treatment of neurologic symptoms is only partially successful, underscoring the need for better understanding
of WD mechanisms and factors that influence disease manifestations. Recent gene and protein profiling studies in animal models
of WD began to uncover cellular processes that are primarily affected by copper accumulation in the liver. The results of
such studies, summarized in this review, revealed new molecular players and pathways (cell cycle and cholesterol metabolism,
mRNA splicing and nuclear receptor signaling) linked to copper misbalance. A systems biology approach promises to generate
a comprehensive view of WD onset and progression, thus helping with a more fine-tune treatment and monitoring of the disorder. 相似文献
17.
Lloyd T. Ackert Jr 《Journal of the history of biology》2006,39(2):373-406
In 1890, Sergei Nikolaevich Vinogradskii (Winogradsky) proposed a novel life process called chemosynthesis. His discovery that some microbes could live solely on inorganic matter emerged during his physiological research in 1880s in Strassburg and Zurich on sulfur, iron, and nitrogen bacteria. In his nitrification research, Vinogradskii first embraced the idea that microbiology could have great bearing on agricultural problems. His critique of agricultural chemists and Kochian-style bacteriologists brought this message to the broader agricultural community, resulting in an heightened interest in biological, rather than chemical methods to investigate soil processes. From 1891 to 1910, he directed the microbiological laboratory at the Imperial Institute of Experimental Medicine in St. Petersburg, Russia, where he expanded his chemosynthesis research to a broad investigation of the manifold significance of autotrophic organisms in soil processes. This work and that of his students attracted the serious attention of agricultural chemists and soil scientists in Russia and abroad, changing essentially the way they understood and investigated the role of microbes in the soil. His student, Vasilii Omelianskii, effectively integrated Vinogradskii’s approach into Russian and Soviet, and international agricultural microbiology. Vinogradskii’s activities in the late 19th century reflect the changes occurring more broadly in science. At that time, microbiologists such as Louis Pasteur, Eugenius Warming, and Martianus Beijerinck were contributing new laboratory methods and theoretical perspectives to incipient disciplines closely related to agriculture: ecology, soil science, and soil microbiology. 相似文献
18.
Perovic S 《Acta biotheoretica》2007,55(3):243-267
Jaegwon Kim's exclusion argument is a general ontological argument, applicable to any properties deemed supervenient on a microproperty basis, including biological properties. It implies that the causal power of any higher-level property must be reducible to the subset of the causal powers of its lower-level properties. Moreover, as Kim's recent version of the argument indicates, a higher-level property can be causally efficient only to the extent of the efficiency of its micro-basis. In response, I argue that the ontology that aims to capture experimentally based explanations of metabolic control systems and morphogenetic systems must involve causally relevant contextual properties. Such an ontology challenges the exclusiveness of micro-based causal efficiency that grounds Kim's reductionism, since configurations themselves are inherently causally efficient constituents. I anticipate and respond to the reductionist's objection that the nonreductionist ontology's account of causes and inter-level causal relations is incoherent. I also argue that such an ontology is not open to Kim's overdetermination objection. 相似文献
19.
20.
Baolu Zhao 《Neurochemical research》2009,34(4):630-638
“Modern” medicine and pharmacology require an effective medical drug with a single compound for a specific disease. This seams
very scientific but usually has unavoidable side effects. For example, the chemical therapy to cancer can totally damage the
immunological ability of the patient leading to death early than non-treatment. On the other hand, natural antioxidant drugs
not only can cure the disease but also can enhance the immunological ability of the patient leading to healthier though they
usually have several compounds or a mixture. For the degenerative disease such as Alzheimer’s disease (AD) and Parkinson’s
disease (PD), natural antioxidant drugs are suitable drugs, because the pathogenesis of these diseases is complex with many
targets and pathways. These effects are more evidence when the clinic trial is for long term treatment. The author reviews
the studies on the protecting effects of natural antioxidants on neurons in neurodegenerative diseases, especially summarized
the results about protective effect of green tea polyphenols on neurons against apoptosis of cellular and animal PD models,
and of genestine and nicotine on neurons against Aβ—induced apoptosis of hippocampal neuronal and transgenic mouse AD models.
Special issue in honor of Dr. Akitane Mori. 相似文献