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1.
Between 1971 and 1975, Fascioloides magna was found in 46 of 67 (69%) feral swine (Sus scrofa) in southern Texas. Flukes were recovered from swine in areas where F. magna commonly has been recovered from white-tailed deer and cattle. One to 12 flukes were recovered from each infected animal. Their presence was indicated by black hematin pigment on the liver and various other internal organs. Eggs were not detected in the gallbladder or feces of infected animals although mature flukes and eggs were recovered in the livers suggesting that, like cattle, feral swine can be infected but are aberrant hosts for the parasite and do not disseminate eggs. 相似文献
2.
Thomas Heiberg Birgit Kriener Tom Tetzlaff Alex Casti Gaute T. Einevoll Hans E. Plesser 《Journal of computational neuroscience》2013,35(3):359-375
Firing-rate models provide a practical tool for studying signal processing in the early visual system, permitting more thorough mathematical analysis than spike-based models. We show here that essential response properties of relay cells in the lateral geniculate nucleus (LGN) can be captured by surprisingly simple firing-rate models consisting of a low-pass filter and a nonlinear activation function. The starting point for our analysis are two spiking neuron models based on experimental data: a spike-response model fitted to data from macaque (Carandini et al. J. Vis., 20(14), 1–2011, 2007), and a model with conductance-based synapses and afterhyperpolarizing currents fitted to data from cat (Casti et al. J. Comput. Neurosci., 24(2), 235–252, 2008). We obtained the nonlinear activation function by stimulating the model neurons with stationary stochastic spike trains, while we characterized the linear filter by fitting a low-pass filter to responses to sinusoidally modulated stochastic spike trains. To account for the non-Poisson nature of retinal spike trains, we performed all analyses with spike trains with higher-order gamma statistics in addition to Poissonian spike trains. Interestingly, the properties of the low-pass filter depend only on the average input rate, but not on the modulation depth of sinusoidally modulated input. Thus, the response properties of our model are fully specified by just three parameters (low-frequency gain, cutoff frequency, and delay) for a given mean input rate and input regularity. This simple firing-rate model reproduces the response of spiking neurons to a step in input rate very well for Poissonian as well as for non-Poissonian input. We also found that the cutoff frequencies, and thus the filter time constants, of the rate-based model are unrelated to the membrane time constants of the underlying spiking models, in agreement with similar observations for simpler models. 相似文献
3.
E?DimitriadisEmail author L?Robb Y-X?Liu AC?Enders H?Martin C?Stoikos E?Wallace LA?Salamonsen 《Reproductive biology and endocrinology : RB&E》2003,1(1):34
Embryo implantation, endometrial stromal cell decidualization and formation of a functional placenta are critical processes in the establishment and maintenance of pregnancy. Interleukin (IL)-11 signalling is essential for adequate decidualization in the mouse uterus and IL-11 promotes decidualization in the human. IL-11 action is mediated via binding to the specific IL-11 receptor α (IL-11Rα). The present study examined immunoreactive IL-11 and IL-11Rα in cycling rhesus monkey endometrium, at implantation sites in cynomolgus and rhesus monkeys and in human first trimester decidua and defined distinct spatial and temporal patterns. In cycling rhesus monkey endometrium, IL-11 and IL-11Rα increased in both basalis and functionalis regions during the secretory compared with the proliferative phase, with changing cellular locations in luminal and glandular epithelium and stroma. The patterns were similar overall to those previously described in human endometrium. Differences were seen in immunostaining during implantation in cynomologus and rhesus monkey. In the cynomolgus, very little staining for IL-11 or IL-11Rα was seen in syncytio- and cyto-trophoblast cells in the villi between days 12 and 150 of pregnancy although there was moderate staining in cytotrophoblast in the shell between days 12 and 17 and in subpopulations of cytotrophoblast cells invading the arteries at day 17. By contrast in the rhesus monkey between days 24 and 35 of pregnancy and in human first trimester placenta, cyto- and syncytio-trophoblast in the villi but not cytotrophoblast in the shell were positively stained. The most intense staining for both IL-11 and IL-11Rα was present within the decidua in the maternal component of implantation sites in all three primates but moderate staining was also present in maternal vascular smooth muscle and glands perivascular cells and epithelial plaques. These results are consistent with a role for IL-11 both during decidualization and placentation in primates. 相似文献
4.
Melek Güler-Yüksel Naomi B Klarenbeek Yvonne PM Goekoop-Ruiterman Jeska K de Vries-Bouwstra Sjoerd M van der Kooij Andreas H Gerards H Karel Ronday Tom WJ Huizinga Ben AC Dijkmans Cornelia F Allaart Willem F Lems 《Arthritis research & therapy》2010,12(3):R96
Introduction
To investigate whether accelerated hand bone mineral density (BMD) loss is associated with progressive joint damage in hands and feet in the first year of rheumatoid arthritis (RA) and whether it is an independent predictor of subsequent progressive total joint damage after 4 years.Methods
In 256 recent-onset RA patients, baseline and 1-year hand BMD was measured in metacarpals 2-4 by digital X-ray radiogrammetry. Joint damage in hands and feet were scored in random order according to the Sharp-van der Heijde method at baseline and yearly up to 4 years.Results
68% of the patients had accelerated hand BMD loss (>-0.003 g/cm2) in the first year of RA. Hand BMD loss was associated with progressive joint damage after 1 year both in hands and feet with odds ratios (OR) (95% confidence intervals [CI]) of 5.3 (1.3-20.9) and 3.1 (1.0-9.7). In univariate analysis, hand BMD loss in the first year was a predictor of subsequent progressive total joint damage after 4 years with an OR (95% CI) of 3.1 (1.3-7.6). Multivariate analysis showed that only progressive joint damage in the first year and anti-citrullinated protein antibody positivity were independent predictors of long-term progressive joint damage.Conclusions
In the first year of RA, accelerated hand BMD loss is associated with progressive joint damage in both hands and feet. Hand BMD loss in the first year of recent-onset RA predicts subsequent progressive total joint damage, however not independent of progressive joint damage in the first year. 相似文献5.
Hansen PS Brix TH Iachine I Sørensen TI Kyvik KO Hegedüs L 《American journal of physiology. Endocrinology and metabolism》2007,292(3):E765-E770
Serum thyrotropin (TSH), free thyroxine (T4), and free triiodothyronine (T3) levels illustrate the thyroid function set point, but the interrelations between these have never been characterized in detail. The aim of this study was to examine the associations between TSH and thyroid hormone levels in healthy euthyroid twins and to determine the extent to which the same genes influence more than one of these biochemical traits; 1,380 healthy euthyroid Danish twins (284 monozygotic, 286 dizygotic, 120 opposite-sex twin pairs) were recruited. Genetic and environmental associations between thyroid function measurements were examined using quantitative genetic modeling. In bivariate genetic models, the phenotypic relation between two measurements was divided into genetic and environmental correlations. Free T4 and free T3 levels were positively correlated (r=0.32, P<0.0001). The genetic correlation between serum free T4 and free T3 levels was rg=0.25 (95% CI 0.14-0.35), suggesting that a set of common genes affect both phenotypes (pleiotropy). The correlation between the environmental effects was re=0.41 (0.32-0.50). From this we calculated that the proportion of the correlation between free T4 and free T3 levels mediated by common genetic factors was 48%. Only 7% of the genetic component of serum free T3 levels is shared with serum free T4. Serum TSH and thyroid hormone levels did not share any genetic influences. In conclusion, thyroid hormone levels are partly genetically correlated genes that affect free T4 levels and exert pleiotropic effects on free T3 levels, although most of the genetic variance for these measurements is trait specific. 相似文献
6.
Markussen MD Heiberg AC Fredholm M Kristensen M 《Journal of biochemical and molecular toxicology》2007,21(6):373-381
The present study characterizes the anticoagulant resistance mechanism in a Danish bromadiolone-resistant strain of Norway rats (Rattus norvegicus), with a Y139C VKORC1 mutation. We compared liver expression of the VKORC1 gene, which encodes a protein of the vitamin K 2,3-epoxide reductase complex, the NQO1 gene, which encodes a NAD(P)H quinone dehydrogenase and the Calumenin gene between bromadiolone-resistant and anticoagulant-susceptible rats upon saline and bromadiolone administration. Additionally, we established the effect of bromadiolone on the gene expression in the resistant and susceptible phenotype. Bromadiolone had no effect on VKORC1 and NQO1 expression in resistant rats, but induced significantly Calumenin expression in the susceptible rats. Calumenin expression was similar between the resistant and the susceptible rats upon saline administration but twofold lower in resistant rats after bromadiolone treatment. These results indicate that Danish bromadiolone resistance does not involve an overexpression of calumenin. Independent of the treatment, we observed a low VKORC1 expression in resistant rats, which in conjugation with the Y139C polymorphism most likely explains the low VKOR activity and the enhanced need for vitamin K observed in Danish resistant rats. Furthermore the bromadiolone resistance was found to be associated with a low expression of the NQO1 gene. 相似文献
7.
Paulo FP Pimenta Alessandra S Orfano Ana C Bahia Ana PM Duarte Claudia M Ríos-Velásquez Fabrício F Melo Felipe AC Pessoa Giselle A Oliveira Keillen MM Campos Luis Martínez Villegas Nilton Barnabé Rodrigues Rafael Nacif-Pimenta Rejane C Sim?es Wuelton M Monteiro Rogerio Amino Yara M Traub-Cseko José BP Lima Maria GV Barbosa Marcus VG Lacerda Wanderli P Tadei Nágila FC Secundino 《Memórias do Instituto Oswaldo Cruz》2015,110(1):23-47
In the Americas, areas with a high risk of malaria transmission are mainly located in
the Amazon Forest, which extends across nine countries. One keystone step to
understanding the Plasmodium life cycle in Anopheles species from the Amazon Region
is to obtain experimentally infected mosquito vectors. Several attempts to colonise
Ano- pheles species have been conducted, but with only short-lived success or no
success at all. In this review, we review the literature on malaria transmission from
the perspective of its Amazon vectors. Currently, it is possible to develop
experimental Plasmodium vivax infection of the colonised and field-captured vectors
in laboratories located close to Amazonian endemic areas. We are also reviewing
studies related to the immune response to P. vivax infection of Anopheles aquasalis,
a coastal mosquito species. Finally, we discuss the importance of the modulation of
Plasmodium infection by the vector microbiota and also consider the anopheline
genomes. The establishment of experimental mosquito infections with Plasmodium
falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide
interesting models for studying malaria in the Amazonian scenario is important.
Understanding the molecular mechanisms involved in the development of the parasites
in New World vectors is crucial in order to better determine the interaction process
and vectorial competence. 相似文献
8.
Maria C Anholeti Rodrigo C Duprat Maria R Figueiredo Maria AC Kaplan Marcelo Guerra Santos Marcelo S Gonzalez Norman A Ratcliffe Denise Feder Selma R Paiva Cicero B Mello 《Memórias do Instituto Oswaldo Cruz》2015,110(5):629-635
Studies evaluated the effects of hexanic extracts from the fruits and flowers
ofClusia fluminensis and the main component of the flower
extract, a purified benzophenone (clusianone), against Aedes
aegypti. The treatment of larvae with the crude fruit or flower extracts
from C. fluminensis did not affect the survival ofAe.
aegypti (50 mg/L), however, the flower extracts significantly delayed
development of Ae. aegypti. In contrast, the clusianone (50 mg/L) isolate from the
flower extract, representing 54.85% of this sample composition, showed a highly
significant inhibition of survival, killing 93.3% of the larvae and completely
blocking development of Ae. aegypti. The results showed, for the first time, high
activity of clusianone against Ae. aegypti that both killed and inhibited mosquito
development. Therefore, clusianone has potential for development as a biopesticide
for controlling insect vectors of tropical diseases. Future work will elucidate the
mode of action of clusianone isolated from C. fluminensis. 相似文献
9.
10.
van Gool CJ van Houwelingen AC Hornstra G 《The Journal of nutritional biochemistry》2000,11(11-12):543-547
Phenylketonuric patients are on a special diet that lacks certain essential fatty acids. This study evaluates the essential fatty acid status of a group of phenylketonuric patients in the Netherlands undergoing dietary treatment. To this end, the essential fatty acid status of nine phenylketonuria patients was studied. On the basis of age and gender, two control subjects were selected for each patient. The essential fatty acid composition of duplicate food portions and the essential fatty acid status of plasma and erythrocytes were analyzed. Phenylketonuria subjects had a different essential fatty acid profile from their peers, especially concerning the n-3 fatty acids. N-6 and n-3 fatty long-chain polyenes were hardly consumed by phenylketonuria subjects, in contrast to the control subjects. Linoleic acid, on the other hand, was consumed in significantly higher amounts by phenylketonuria subjects and made up about 40% of their daily fat consumption. The essential fatty acid consumption pattern of the phenylketonuria subjects is mirrored by the essential fatty acid concentrations in blood. The essential fatty acid status of the phenylketonuric diet should be improved in order to prevent deficiency in n-3 fatty acids. 相似文献