Overview of the Mars Pathfinder mission and assessment of landing site predictions

Chemical analyses returned by Mars Pathfinder indicate that some rocks may be high in silica, implying differentiated parent materials. Rounded pebbles and cobbles and a possible conglomerate suggest fluvial processes that imply liquid water in equilibrium with the atmosphere and thus a warmer and wetter past. The moment of inertia indicates a central metallic core of 1300 to 2000 kilometers in radius. Composite airborne dust particles appear magnetized by freeze-dried maghemite stain or cement that may have been leached from crustal materials by an active hydrologic cycle. Remote-sensing data at a scale of generally greater than approximately 1 kilometer and an Earth analog correctly predicted a rocky plain safe for landing and roving with a variety of rocks deposited by catastrophic floods that are relatively dust-free.     

Economic values in broiler breeding

The objectives of this study were to derive economic values in broiler breeding and to determine their relationship with production circumstances. Economic values were derived using a deterministic economic model based on profit equations with a fixed amount of broiler meat output of the production system. Nonintegrated and the integrated broiler production systems were studied. The difference between these originates from different definitions of cost components and scaling aspects. For each stage of an nonintegrated system, the model calculated the profit margin; for an integrated system, (total) cost prices per unit of product at each stage were calculated. The Dutch broiler performance data and prices were input into the model as the representative situation. For all traits, in the nonintegrated system, economic values were derived, expressed as Dutch guilders (Dfl) per unit of product, where the unit of product depends on the stage of the production system and equals an egg for the multiplier breeder, a day-old chick for the hatchery, and a marketable broiler for the commercial grower and processor. Resulting levels of economic values were illustrated by showing underlying cost or profit changes in the production system. For the integrated system, economic values were expressed as Dfl x marketable broiler(-1) x unit(-1). Economic values of traits in the integrated system were also derived for situations where technical parameters or prices of productive factors were changed (20% increase or decrease). A general conclusion from these sensitivity analyses is that the economic values are sensitive to production levels, product prices and feed prices; there are both linear and nonlinear relationships between economic values and production circumstances.     

Brainstem auditory evoked response development in preterm and term baboons (Papio hamadryas)

Brainstem auditory evoked responses were recorded longitudinally from 11 neonatal baboons (Papio hamadryas), 6 of which were preterm. Recordings were made in unsedated animals from day 161 to day 362 after conception (term = 182 days). The pattern of development of both waveform morphology and of wave latency was consistent with that seen in the human neonate, with a rapid maturation of the response during the perinatal period, and then a slower development to adult values. Brainstem conduction time was measured from the wave I to wave IV interval, and this demonstrated a similar pattern, with a rapid decrease in latency up to term, and then decreasing more slowly to reach adult values by 4 months of age in the baboon.     

Comparison of drug binding interactions on human, rat and rabbit serum albumin using high-performance displacement chromatography

The binding of warfarin, a series of non-steroidal anti-inflammatory drugs and a series of benzodiazepines to rat serum albumin (RatSA) and rabbit serum albumin (RabSA) was compared with their binding to human serum albumin (HSA) using high-performance liquid chromatography on stationary phases based on immobilized albumins. The effect of the addition to the mobile phase of compounds known to bind to HSA at site I (phenylbutazone) or at site II (R- and S-ibuprofen) or at both sites (2,3,5-triiodobenzoic acid) was investigated on all three proteins. The results indicated that for the chiral compounds studied, the stereoselectivity of drug binding was much lower on RatSA than on HSA. On RatSA and RabSA, the benzodiazepine site was not a major binding site for R- and S-ibuprofen. The results indicated the existence of two binding sites for R and S warfarin on RatSA and probably on RabSA. On RatSA, one site is the major stereoselective site and is the major binding site of phenylbutazone and piroxicam. The other one is a major binding site for R- and S-ibuprofen and R- and S-ketoprofen.     

Generation and characterization of gp100 peptide-specific NK-T cell clones

MHC-restricted cytotoxic T lymphocytes (CTLs) specific for antigens expressed by malignant cells are important components of immune responses against human cancer. Peripheral blood monocytes of HLA-A2+ healthy donors were used to induce dendritic cells (DCs) by granulocyte-macrophage colony-stimulating factor and interleukin-4 and loaded with a gp100 peptide (YLEPGPVTA). By applying these peptide-loaded DCs, a CTL line that displayed high cytotoxic reactivity with peptide-loaded target cells was generated. A total of 11 gp100 peptide-specific CTL clones were generated from this cell line. Several of these CTL clones were studied in detail. Of particular interest was clone CTL-45, which, contrary to the parental cell line, displayed strong NK activity and, by flow-cytometric analysis, revealed a CD3+, TCR BV17, CD8+ and CD56+ phenotype. This clone was strictly peptide-specific and effectively killed a panel of melanoma cells expressing HLA-A2 and gp100. Tumor-specific T cells with this kind of dual function are potentially of great clinical importance as they have a backup mechanism that may go into action when tumor cells escape specific killing by losing their HLA-class I molecules.