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Human RSV is one of the most prevalent viral pathogens of early childhood for which no vaccine is available. Herein we provide an analysis of RSV epitope data to examine its application to vaccine design and development. Our objective was to provide an overview of antigenic coverage, identify critical antibody and T cell determinants, and then analyze the cumulative RSV epitope data from the standpoint of functional responses using a combinational approach to characterize antigenic structure and epitope location. A review of the cumulative data revealed, not surprisingly, that the vast majority of epitopes have been defined for the two major surface antigens, F and G. Antibody and T cell determinants have been reported from multiple hosts, including those from human subjects following natural infection, however human data represent a minority of the data. A structural analysis of the major surface antigen, F, showed that the majority of epitopes defined for functional antibodies (neutralizing and/or protective) were either shown to bind pre-F or to be accessible in both pre- and post-F forms. This finding may have has implications for on-going vaccine design and development. These interpretations are in agreement with previous work and can be applied in the larger context of functional epitopes on the F protein. It is our hope that this work will provide the basis for further RSV-specific epitope discovery and investigation into the nature of antigen conformation in immunogenicity.  相似文献   
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A light-weight nonmagnetic, nonconductive instrument has been devised for use with magnetic resonance imaging, computerized tomography, and digital subtraction imaging for work in the field of epilepsy, brain tumors and vascular lesions. The apparatus' main characteristic is its ability to use optionally either the lateral orthogonal or the spherical-radial approach.  相似文献   
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Hybrid formation within the genus Leishmania?   总被引:4,自引:0,他引:4  
Leishmanial organisms isolated from a desert rodent (Psammomys obesus) and a feral dog (Canis familiaris) in the Eastern Province of Saudi Arabia were isoenzymically distinct from Leishmania major and L. arabica, organisms usually associated with human and wild animal cutaneous leishmaniasis in this area. Further examination of isoenzyme banding patterns of cloned populations of these organisms, together with karyotyping using orthogonal field alternation gel electrophoresis and the use of highly specific kinetoplast DNA probes, has produced evidence suggesting that these organisms isolated from the dog and the rodent are hybrids of L. major and L. arabica.  相似文献   
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Decreases in pH and increases in the concentration of Al and NO 3 have been observed in surface waters draining acid-sensitive regions in the northeastern U.S. during spring snowmelt. To assess the source of this acidity, we evaluated solute concentrations in snowpack, and in meltwater collected from snow and forest floor lysimeters in the west-central Adirondack Mountains of New York during the spring snowmelt period, 29 March through 15 April 1984.During the initial phase of snowmelt, ions were preferentially leached from the snowpack resulting in elevated concentrations in snowmelt water (e.g. H+ = 140 eq.l–1; NO 4 2– = 123 eq.l–1; SO 3 = 160 eq.l–1). Solute concentrations decreased dramatically within a few days of the initial melt (< 50 eq.l–1). The concentrations of SO 4 2– and NO 3 in snowpack and snowmelt water were similar, whereas NO 3 in the forest floor leachate was at least two times the concentration of SO 4 2– .Study results suggest that the forest floor was a sink for snowmelt inputs of alkalinity, and a net source of H+, NO 3 , dissolved organic carbon, K+ and Al inputs to the mineral soil. The forest floor was relatively conservative with respect to snowmelt inputs of Ca2+, SO 4 2– and Cl. These results indicate that mineralization of N, followed by nitrification in the forest floor may be an important process contributing to elevated concentrations of H+ and NO 3 in streams during the snowmelt period.  相似文献   
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Acyclic beef cows received 1.0, 2.5 or 5.0 micrograms GnRH/2 h for 48 h as 24 X 2 h repeated i.v. injections or by continuous i.v. infusion. Preovulatory-type LH surges were detected in 9/18 injected and 8/15 infused cows and occurred 30.6 +/- 5.1 h and 3.3 +/- 0.7 h after the start of treatment respectively. Cows receiving the lowest infusion dose did not exhibit gonadotrophin surges. The LH response to individual injections increased with dose but the proportion of injected cows showing preovulatory-type surges at each dose level did not change. A total of 20 cows (10 injected and 10 infused) showed evidence of luteal activity within 7 days of the end of GnRH treatment, although this was transitory in most animals. Cows which exhibited preovulatory-type LH surges in response to treatment had significantly higher plasma oestradiol-17 beta concentrations and lower FSH concentrations before treatment than those which did not. The results suggest that the LH response to GnRH treatment is dependent on follicular status in the immediate pretreatment period.  相似文献   
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