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451.
Ariana Ern Schmitz Paulo Alexandre de Oliveira Luiz F. de Souza Danilo Grünig Humberto da Silva Samara Danielski Danúbia Bonfanti Santos Eduardo Alves de Almeida Rui Daniel Prediger Andrew Fisher Marcelo Farina Alcir Luiz Dafre 《Biological trace element research》2014,158(3):399-409
Manganese (Mn) exposure is related to industrial activities, where absorption by inhalation has high relevance. Manganism, a syndrome caused as a result of excessive accumulation of Mn in the central nervous system, has numerous symptoms similar to those seen in idiopathic Parkinson disease (IPD). Some of these symptoms, such as learning, memory, sensorial, and neurochemical changes, appear before the onset of motor deficits in both manganism and IPD. The aim of this study was to evaluate the possible neuroprotective effects of curcumin against behavioral deficits induced by Mn toxicity in young (2 months old) Swiss mice. We evaluated the effect of chronic inhalation of a Mn mixture [Mn(OAc)3 and MnCl2 (20:40 mM)], 1 h/session, three times a week, over a 14-week period on behavioral and neurochemical parameters. Curcumin was supplemented in the diet (500 or 1,500 ppm in food pellets). The Mn disrupted the motor performance evaluated in the single-pellet reach task, as well as the short- and long-term spatial memory evaluated in the step-down inhibitory avoidance task. Surprisingly, curcumin also produced similar deleterious effects in such behavioral tests. Moreover, the association of Mn plus curcumin significantly increased the levels of Mn and iron, and decreased the levels of dopamine and serotonin in the hippocampus. These alterations were not observed in the striatum. In conclusion, the current Mn treatment protocol resulted in mild deficits in motor and memory functions, resembling the early phases of IPD. Additionally, curcumin showed no beneficial effects against Mn-induced disruption of hippocampal metal and neurotransmitter homeostasis. Figure
? 相似文献
452.
Rosan Barbosa de Matos Suzana Braga-de-Souza Bruno Pena Seara Pitanga Victor Diógenes Amaral da Silva Erica Etelvina Viana de Jesus Alexandre Morales Pinheiro Maria de Fátima Dias Costa Ramon dos Santos El-Bacha Cátia Suse de Oliveira Ribeiro Silvia Lima Costa 《The Korean journal of parasitology》2014,52(6):613-619
Neospora caninum (Apicomplexa; Sarcocystidae) is a protozoan that causes abortion in cattle, horses, sheep, and dogs as well as neurological and dermatological diseases in dogs. In the central nervous system of dogs infected with N. caninum, cysts were detected that exhibited gliosis and meningitis. Flavonoids are polyphenolic compounds that exhibit antibacterial, antiparasitic, antifungal, and antiviral properties. In this study, we investigated the effects of flavonoids in a well-established in vitro model of N. caninum infection in glial cell cultures. Glial cells were treated individually with 10 different flavonoids, and a subset of cultures was also infected with the NC-1 strain of N. caninum. All of the flavonoids tested induced an increase in the metabolism of glial cells and many of them increased nitrite levels in cultures infected with NC-1 compared to controls and uninfected cultures. Among the flavonoids tested, 3'',4''-dihydroxyflavone, 3'',4'',5,7-tetrahydroxyflavone (luteolin), and 3,3'',4'',5,6-pentahydroxyflavone (quercetin), also inhibited parasitophorous vacuole formation. Taken together, our findings show that flavonoids modulate glial cell responses, increase NO secretion, and interfere with N. caninum infection and proliferation. 相似文献
453.
Mather KA Molina J Flowers JM Rubinstein S Rauh BL Lawton-Rauh A Caicedo AL McNally KL Purugganan MD 《Molecular ecology》2010,19(22):4892-4905
Understanding how crop species spread and are introduced to new areas provides insights into the nature of species range expansions. The domesticated species Oryza sativa or Asian rice is one of the key domesticated crop species in the world. The island of Madagascar off the coast of East Africa was one of the last major Old World areas of introduction of rice after the domestication of this crop species and before extensive historical global trade in this crop. Asian rice was introduced in Madagascar from India, the Malay Peninsula and Indonesia approximately 800-1400 years ago. Studies of domestication traits characteristic of the two independently domesticated Asian rice subspecies, indica and tropical japonica, suggest two major waves of migrations into Madagascar. A population genetic analysis of rice in Madagascar using sequence data from 53 gene fragments provided insights into the dynamics of island founder events during the expansion of a crop species' geographic range and introduction to novel agro-ecological environments. We observed a significant decrease in genetic diversity in rice from Madagascar when compared to those in Asia, likely the result of a bottleneck on the island. We also found a high frequency of a unique indica type in Madagascar that shows clear population differentiation from most of the sampled Asian landraces, as well as differential exchange of alleles between Asia and Madagascar populations of the tropical japonica subspecies. Finally, despite partial reproductive isolation between japonica and indica, there was evidence of indica/japonica recombination resulting from their hybridization on the island. 相似文献
454.
Ye J Sorrell EM Cai Y Shao H Xu K Pena L Hickman D Song H Angel M Medina RA Manicassamy B Garcia-Sastre A Perez DR 《PLoS pathogens》2010,6(10):e1001145
A novel, swine-origin influenza H1N1 virus (H1N1pdm) caused the first pandemic of the 21st century. This pandemic, although efficient in transmission, is mild in virulence. This atypical mild pandemic season has raised concerns regarding the potential of this virus to acquire additional virulence markers either through further adaptation or possibly by immune pressure in the human host. Using the mouse model we generated, within a single round of infection with A/California/04/09/H1N1 (Ca/04), a virus lethal in mice--herein referred to as mouse-adapted Ca/04 (ma-Ca/04). Five amino acid substitutions were found in the genome of ma-Ca/04: 3 in HA (D131E, S186P and A198E), 1 in PA (E298K) and 1 in NP (D101G). Reverse genetics analyses of these mutations indicate that all five mutations from ma-Ca/04 contributed to the lethal phenotype; however, the D131E and S186P mutations--which are also found in the 1918 and seasonal H1N1 viruses-in HA alone were sufficient to confer virulence of Ca/04 in mice. HI assays against H1N1pdm demonstrate that the D131E and S186P mutations caused minor antigenic changes and, likely, affected receptor binding. The rapid selection of ma-Ca/04 in mice suggests that a virus containing this constellation of amino acids might have already been present in Ca/04, likely as minor quasispecies. 相似文献
455.
The centromere-specific histone variant CENP-A (CID in Drosophila) is a structural and functional foundation for kinetochore formation and chromosome segregation. Here, we show that overexpressed CID is mislocalized into normally noncentromeric regions in Drosophila tissue culture cells and animals. Analysis of mitoses in living and fixed cells reveals that mitotic delays, anaphase bridges, chromosome fragmentation, and cell and organismal lethality are all direct consequences of CID mislocalization. In addition, proteins that are normally restricted to endogenous kinetochores assemble at a subset of ectopic CID incorporation regions. The presence of microtubule motors and binding proteins, spindle attachments, and aberrant chromosome morphologies demonstrate that these ectopic kinetochores are functional. We conclude that CID mislocalization promotes formation of ectopic centromeres and multicentric chromosomes, which causes chromosome missegregation, aneuploidy, and growth defects. Thus, CENP-A mislocalization is one possible mechanism for genome instability during cancer progression, as well as centromere plasticity during evolution. 相似文献
456.
457.
We studied five microsatellites (DXS995, DXS8076, DXS8114, DXS1002 and DXS1050) located in a region of very low recombination rate in the long arm of the human X chromosome (Xq13.3–Xq21.3). No recombination
was seen in 291 meioses in CEPH families. To test whether haplotypes composed of the five microsatellites could differentiate
among distinct human continental populations, we studied an international panel containing 72 males from Africa, Europe, Asia
and the America. Haplotypic diversity was very high within these groups and no haplotypes were shared among them. This led
to the hope that we might be able to identify continent-specific lineages. However, in a median joining network there was
no clear discrimination of the different continental groups. We then tested whether we could identify X chromosomal lineages
from different continental origins in Brazilians. We typed 180 white Brazilians from four different geographical regions and
examined their proportions of haplotype sharing with Africans, Asians, Europeans and Amerindians. No phylogeographical patterns
emerged from the data. Moreover, there were several instances of the same haplotype being shared by many (and in one instance
all) groups, suggesting that recombination might be occurring. We thus studied pairwise the level of linkage disequilibrium
(LD) between the microsatellites. No detectable linkage disequilibrium between the most external loci DXS995 and DXS1050 was observed. Thus, even though recombination may be absent on short time spans, as seen in the CEPH pedigrees, on a long
term basis it occurs often enough to dissipate all linkage disequilibrium. On the other hand, we observed very strong linkage
disequilibrium between the pairs DXS995/DXS8076 and DXS1002/DXS8114, raising the possibility of resequencing the segment between them to identify single nucleotide polymorphisms (SNPs) in their
intervals. The combination of X-linked microsatellites and SNPs in strong linkage disequilibrium might provide a powerful
new tool to investigate human demographic history. 相似文献
458.
We have previously shown that the Y chromosomes of ‘white’ Brazilians have their immediate geographical origin in Europe,
with low frequency of sub-Saharan African chromosomes and virtual absence of Amerindian contribution. The typing of slow evolving
polymorphisms on the Y chromosome also revealed no differences between Brazilians and Portuguese, the bulk of European immigrants
to Brazil, and even among Brazilians from distinct regions of Brazil, the latter being in sharp contrast with mtDNA data.
In order to test if the lack of differentiation is a sex-biased and not a marker-biased phenomenon, we decided to study faster
evolving Y chromosome markers in samples from Brazil and Portugal previously studied. The population structure revealed by
this work confirmed that there were indeed no significant differences between Brazil and Portugal and no population differentiation
within the four geographical regions of Brazil, suggesting that this phenomenon is unrelated to the nature of the markers
typed. Nevertheless the fast evolving markers did uncover a higher within population diversity in Brazil than Portugal, which
could be explained by the input of diverse European Y chromosomes carried by several migration waves to Brazil. Our present
data highlight the significance of typing and combining Y markers that evolve according to distinct mutational paces to usefully
assess the levels of diversity in a given population, and can be applied in the study of populations derived from distinct
geographical origins such as the Brazilians. 相似文献
459.
Samara Joy Nielsen Anna Maria Siega‐Riz Barry M. Popkin 《Obesity (Silver Spring, Md.)》2002,10(5):370-378
Objective: To determine the trends in locations and food sources of Americans stratified by age group for both total energy and the meal and snack subcomponents. Research Methods and Procedures: Nationally representative data was taken from the 1977 to 1978 Nationwide Food Consumption Survey and the 1989 to 1991 and 1994 to 1996 (and 1998 for children age 2 through 9) Continuing Surveys of Food Intake by Individuals. The sample consisted of 63,380 individuals, age 2 and up. For each survey year, the percentage of total energy intake from meals and snacks was calculated separately for 2‐ to 18‐year‐olds, 19‐ to 39‐year‐olds, 40‐ to 59‐year‐olds, and those 60 years and older. The percentage of energy intake by location (at‐home consumption or preparation, vending, store eaten out, restaurant/fast‐food, and school) and by specific food group was computed for all age groups separately. Results: The trends in location and food sources were almost identical for all age groups. Key dietary behavior shifts included greater away‐from‐home consumption; large increases in total energy from salty snacks, soft drinks, and pizza; and large decreases in energy from low‐ and medium‐fat milk and medium‐ and high‐fat beef and pork. Discussion: Total energy intake has increased over the past 20 years, with shifts away from meals to snacks and from at‐home to away‐from‐home consumption. The similarity of changes across all age groups furthers the assertion that broad‐based environmental changes are needed to improve the diets of Americans. 相似文献
460.