Embryonic resistance to tumour necrosis factor-alpha mediated cytotoxicity: novel mechanism underlying maternal immunological tolerance to the fetal allograft

The cytokine tumour necrosis factor-alpha (TNF alpha) has been postulated to play an essential role in the cytotoxic activity of cell-mediated immunity against allogenic or tumour cells invading the host. Several tumour cell lines, however, are resistant to TNF mediated cytotoxicity and respond paradoxically by cellular proliferation and by autocrine secretion of TNF alpha. In view of the metastatic character of the mammalian embryo, the aim of this study was to assess the potential of murine embryos to secrete TNF alpha in vitro, to express TNF receptors and to resist TNF alpha mediated cytotoxicity during their in-vitro development to the blastocyst stage. The potential of human embryos to secrete TNF alpha in vitro until the blastocyst stage was also investigated. From a total of 11 human embryos, which were allowed to proceed to blastocyst formation, seven secreted TNF alpha in the range of 2-117 pg/ml/24 h. A total of 123 C57BL/6J mouse embryos were studied of which 55% secreted TNF alpha in the range of 1.25-3.95 mg/ml/24 h. The presence of high levels of exogenous TNF alpha (10-300 IU) was not detrimental to the in-vitro development of murine embryos. Using immunohistochemical techniques, we were not able to detect the presence of type I or II TNF receptors on the surface of murine embryos. Our findings suggest that human and C57BL/6J murine embryos have the potential to secrete TNF alpha in vitro during the developmental stages leading to blastocyst formation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Attributions as inferences and explanations: Conjunction effects.

When asked to estimate the probability of an interpretation for an event, observers may either assess whether the event can give rise to the interpretation (an inference set) or assess whether the interpretation can give rise to the event (an explanation set). These two strategies may moderate the conjunction effects (Leddo, Abelson, & Gross, 1984)—attributors' tendency to assign lower probabilities to single-reason interpretations than to their conjunctions. Our two studies showed that explanation-set instructions (e.g., "assess the probability that the interpretation could be the reason for the event") produced stronger conjunction effects than inference-set instructions (e.g., "assess the probability that the interpretation could be inferred from the event"). This Set (inference or explanation)?×?Reason (multiple or single) interaction was not affected by whether the events involved voluntary or involuntary behavior or by whether they described events that happened or failed to happen. In a third study, we found that subjects in an inference set were more likely to report that they estimated probability of the interpretation (as opposed to probability of the behavior) than were subjects in an explanation set. The extent to which the explanation set may account for conjunction effects obtained in other studies was discussed. Possible implications and determinants of the inference-explanation distinction were also considered. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Digestibility by sheep of total and cell wall monosaccharides of wheat straw treated chemically or chemically plus enzymatically

Digestibility of total and cell wall monosaccharides was studied in sheep with ruminal and duodenal cannulae and fed three wheat straw-based diets: untreated, treated with SO2, treated with SO2 plus cellulase and a fourth diet, which was barley-based. In untreated straw, 90% of total monosaccharides are cell wall bound. Sulfur dioxide treatment solubilized mainly the matrix sugars, reducing their content from 22.1 to 9.76 g/100 g DM in straw. The combined treatment (SO2 plus cellulase) solubilized most of the cell wall sugars so that the most of the cell wall sugars so that the residual cell wall contained only 31% of the total sugars originally present. Treatments increased total monosaccharide digestibility from 63 to 90% and of cell wall monosaccharides from 58 to 84 and 88%. The proportion of digestible monosaccharides degraded in the rumen was increased up to 95% by the treatments. Total monosaccharide digestibility was similar in both treated straws, but degradation of the residual cell wall monosaccharides was somewhat lower in the combined treatment compared with the SO2-treated straw.     

Composition and in-vitro digestibility of carbohydrates of wheat plants harvested at bloom and soft-dough stages

Wheat plants (Triticum aestivum) were harvested at the bloom and soft-dough stages, separated into leaves + sheaths, stems and spikes, and the effect of stage of maturity on neutral detergent fibre (NDF) composition and degradability was studied, the accumulation of starch in the spikes compensated for the decrease in the degradability of NDF polysaccharides so that the in-vitro digestibility of the organic matter (OM) was not changed between the bloom and soft-dough stages. Minor compositional changes occurred in the NDF of the various botanical fractions which can hardly explain the drop in NDF degradability with maturity. There was a decline in the ratio of hemicellulose to lignin, and the changes in NDF-monosaccharide degradability were probably related to the extension of covalent bonding between those matrix components during maturation. Irrespective of botanical fraction and maturity stage, NDF xylose was less digestible than NDF glucose. Between bloom and soft-dough stages there was an increase of 36% in the yield of digestible OM.     

Power and Resource Allocation in Wireless Communication Network

Wireless Personal Communications - Present-day wireless methods are necessary to support a variety of higher-speed data communication facilities for its subscribers such as cloud-based video...     

In vitro characterization of PBLG-g-HA/ PLLA nanocomposite scaffolds

The purpose of the present study was to synthesize a new composites scaffold containing poly(γ-benzyl-L-glutamate) modified hydroxyapatite/(poly(L-lactic acid))(PBLG-g-HA/PLLA) and to investigate their in vitro behaviour on bone mesenchymal stromal cells(BMSCs). The results demonstrated that BMSC proliferation was signifi cantly increased on PBLG-g-HA/PLLA scaffolds after 3 and 7 days post seeding when compared to PLLA and HA/PLLA scaffolds. The in vitro osteogenic differentiation also favoured the composite PBLG-g-HA/PLLA scaffolds when compared to controls by signifi cantly increasing Runx2, ALP or osteocalcin mRNA expression as assessed by real-time PCR. The results illustrate the potential of PBLG-g-HA/PLLA scaffolds for bone tissue engineering applications. And the in vivo testing further confi rms the PBLG-gHA/PLLA scaffolds' potentioal for healing critical bone defects.