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991.
The zebrafish (Danio rerio) has been long advocated as a model for cancer research, but little is known about the real molecular similarities between zebrafish and human tumors. Comparative analysis of microarray data from zebrafish liver tumors with those from four human tumor types revealed molecular conservation at various levels between fish and human tumors. This approach provides a useful strategy for identifying an expression signature that is strongly associated with a disease phenotype.  相似文献   
992.
Summary Ribonucleic acid extracts of lymphoid cells from immune hosts were used to transfer in vivo and in vitro cell-mediated immune reactivity to a variety of antigens. The in vivo immune responses transferred by RNA included the delayed cutaneous hypersensitivity reaction to fungal and chemically-defined antigens and the tumor-rejection reaction to guinea pig hepatoma antigens. The in vitro immune responses transferred by RNA included macrophage migration inhibition by fungal, chemically-defined, and tumor antigens. The transfer activity of RNA preparations was contained in the 8 s to 18 s species of RNA and was sensitive to RNAse but not to DNase or trypsin. Antigen was not detectable in the RNA preparations and appeared to have no role in the transfer activity. Syngeneic, allogeneic, or xenogeneic sources of RNA could transfer immune reactivity. In each system tested, the transfer of cell-mediated reactivity by RNA was specific for the antigen used to sensitize the RNA donor. The potential use of RNA-mediated transfer of immunity is discussed.  相似文献   
993.
994.
This paper examines the critical attitude of behavioral professionals toward spiritual phenomena, and the current growing openness toward a scientific study of spirituality and its effects on health. Health care professionals work amidst sickness and suffering, and become immersed in the struggles of suffering persons for meaning and spiritual direction. Biofeedback and neurofeedback training can facilitate relaxation, mental stillness, and the emergence of spiritual experiences. A growing body of empirical studies documents largely positive effects of religious involvement on health. The effects of religion and spirituality on health are diverse, ranging from such tangible and easily understood phenomena as a reduction of health-risk behaviors in church-goers, to more elusive phenomena such as the distant effects of prayer on health and physiology. Psychophysiological methods may prove useful in identifying specific physiological mechanisms mediating such effects. Spirituality is also a dimension in much of complementary and alternative medicine (CAM), and the CAM arena may offer a window of opportunity for biofeedback practice.  相似文献   
995.
To investigate differences in leaf structure, chlorophyll and nutrients on terminal branches of the understory tree Asimina triloba, the first (proximal) and the last (distal) leaves to develop in the spring were compared. Proximal leaf expansion was completed before the overstory canopy was fully closed but distal leaf expansion occurred during and after the development of the overstory canopy. Fully expanded proximal leaves were 76% smaller in area, were 18% thicker and had 36% more stomates per m of leaf area when compared to distal leaves. In addition, maximum stomatal conductance to water vapor was greater (150 vs. 120 mmol m−-2s−-1) and the minimum PPFD required for maximum conductance was higher (200 vs. 150 μmol m−-2s−-1) for the proximal leaves. Chlorophyll content was also greater for proximal leaves, but nitrogen and phosphorus contents were lower throughout the entire summer. Seasonal measurements indicated an increase in chlorophyll a content and reductions in nitrogen content throughout the summer growth period for leaves from both positions. The results suggest that distal and proximal leaves differed physiologically and that the measured differences were related to the changing irradiance environment during leaf development. The time of leaf expansion, as indicated by leaf position on the branch, may be an important consideration when examining the water and photosynthetic relations of understory trees.  相似文献   
996.
997.
Diabetes mellitus and its complications are the third leading cause of death in the world, exceeded only by cardiovascular disease and cancer. Tighter monitoring and control of blood glucose could minimize complications associated with diabetes. Recently, optical coherence tomography (OCT) for noninvasive glucose monitoring was proposed and tested in vivo. The aim of this work was to investigate the influence of changes in blood glucose concentration ([glu]) and sodium concentration ([Na+]) on the OCT signal. We also investigated the influence of other important analytes on the sensitivity of glucose monitoring with OCT. The experiments were carried out in anesthetized female pigs. The OCT images were acquired continuously from skin, while [glu] and [Na+] were experimentally varied within their physiological ranges. Correlations of the OCT signal slope with [glu] and [Na+] were studied at different tissue depths. The tissue area probed with OCT was marked and cut for histological examination. The correlation of blood [glu] and [Na+] with the OCT signal slope was observed in separate tissue layers. On average, equimolar changes in [glu] produced 2.26 +/- 1.15 greater alterations of the OCT signal slope than changes in [Na+]. Variation of concentrations of other analytes did not influence the OCT signal slope. The influence of [Na+] on relative changes in the OCT signal slope was generally less than [glu]-induced changes. OCT is a promising method for noninvasive glucose monitoring because of its ability to track the influence of changing [glu] on individual tissue layers.  相似文献   
998.
A novel series of dual EGFR and HER2 inhibitors based on the pyrrolo[2,1-f][1,2,4]triazine nucleus is described. A general route toward their synthesis, which enables functionalization at multiple sites, has been developed. Biological evaluation in enzymatic and cell-based assays has identified a series of C-6 carbamates with potent biochemical and cellular activities.  相似文献   
999.
We tested whether daily mortality rates (DMR) of smallmouth bass offspring were influenced by life interval, offspring density and growth, parental male attributes, and selected mortality factors during parental care in a regulated Virginia stream. Mortality averaged 9.5% per day (range 5.2–13.9%) and 94.1% total (range 80.9–99.5%) from egg deposition to the juvenile period (29–36 d) for individual broods. Offspring losses were primarily attributed to fungus (Saprolegnia parasitica) infection of eggs and to American eel, Anguilla rostrata, predation. DMR were significantly higher for the interval from swim-up of larvae to metamorphosis relative to earlier and later intervals. There was no significant autocorrelation of DMR among life intervals for individual broods, indicating that relative mortality rates were inconsistent among broods through time. DMR were also uncorrelated with the number of offspring per brood, offspring growth rates, and parental male attributes, except during egg and embryo intervals. Daily egg mortality was negatively related to male size and positively related to the number of eggs per nest, suggesting that density-dependent egg mortality may have been partially offset in nests of larger males. Larger males received more eggs, tended to maintain larger broods throughout parental care, and contributed a high proportion of the total number of juveniles reared. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
1000.
The primary structure of the neurohormone crustacean hyperglycemic hormone (CHH-II) was determined by means of enzymatic digestions, manual Edman degradation, and mass spectrometry. CHH-II is a 72 residue peptide (molecular mass 8388 Da), with six cysteines forming three disulfide bridges that connect residues 7–43, 23–39, and 26–52. The peptide has blocked N- and C-termini, and lacks tryptophan, histidine, and methionine. The CHH-I and CHH-II of Procambarus bouvieri have identical sequences and elicit levels of hyperglycemia that are not distinguishable. The difference between the two isomorphs consists in a posttranslational modification of a l-Phe in CHH-I to a d-Phe in CHH-II at the third position from the N-terminus.  相似文献   
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