Expression screening of a yeast artificial chromosome contig refines the location of the mouse H3a minor histocompatibility antigen gene

The H3 complex, on mouse Chromosome 2, is an important model locus for understanding mechanisms underlying non-self Ag recognition during tissue transplantation rejection between MHC-matched mouse strains. H3a is a minor histocompatibility Ag gene, located within H3, that encodes a polymorphic peptide alloantigen recognized by cytolytic T cells. Other genes within the complex include beta2-microglobulin and H3b. A yeast artificial chromosome (YAC) contig is described that spans the interval between D2Mit444 and D2Mit17, a region known to contain H3a. This contig refines the position of many genes and anonymous loci. In addition, 23 new sequence-tagged sites are described that further increase the genetic resolution surrounding H3a. A novel assay was developed to determine the location of H3a within the contig. Representative YACs were modified by retrofitting with a mammalian selectable marker, and then introduced by spheroplast fusion into mouse L cells. YAC-containing L cells were screened for the expression of the YAC-encoded H3a(a) Ag by using them as targets in a cell-mediated lympholysis assay with H3a(a)-specific CTLs. A single YAC carrying H3a was identified. Based on the location of this YAC within the contig, many candidate genes can be eliminated. The data position H3a between Tyro3 and Epb4.2, in close proximity to Capn3. These studies illustrate how genetic and genomic information can be exploited toward identifying genes encoding not only histocompatibility Ags, but also any autoantigen recognized by T cells.     

Neuronal units linked to microvascular modules in cerebral cortex: response elements for imaging the brain

How neuronal activity changes cerebral blood flow is of biological and practical importance. The rodent whisker-barrel system has special merits as a model for studies of changes in local cerebral blood flow (LCBF). Stimulus-evoked changes in neural firing and 'intrinsic signals' recorded through a cranial window were used to define regions of interest for repeated flow measurements. Whisker-activated changes in flow were measured with intravascular markers at the pia. LCBF changes were always prompt and localized over the appropriate barrel. Stimulus-related changes in parenchymal flow monitored continuously with H2 electrodes recorded short latency flow changes initiated in middle cortical layers. Activation that increased flow to particular barrels often led to reduced flow to adjacent cortex. Dye was injected into single penetrating arterioles from the pia of the fixed brain and injected into arterioles in slices of cortex where barrels were evident without stains. Arteriolar and venular domains at the surface were not directly related to underlying barrels. Capillary tufts in layer IV were mainly coincident with barrels. The matching between a capillary plexus (a vascular module) and a barrel (a functional neuronal unit) is a spatial organization of neurons and blood vessels that optimizes local interactions between the two. The paths of communication probably include: neurons to neurons, neurons to glia, neurons to vessels, glia to vessels, vessels to vessels and vessels to brain. Matching a functional grouping of neurons with a vascular module is an elegant means of reducing the risk of embarrassment for energy-expensive neuronal activity (ion pumping) while minimizing energy spent for delivery of the energy (cardiac output). For imaging studies this organization sets biological limits to spatial, temporal and magnitude resolution. Reduced flow to nearby inactive cortex enhances local differences.     

Shifting physician prescribing to a preferred histamine-2-receptor antagonist. Effects of a multifactorial intervention in a mixed-model health maintenance organization

Three receptor tyrosine kinases of the PDGF receptor family (RTKP) that clustered within 1000 Kb of the mouse chromosome 5 constitute an interesting unit that are expressed in three distinct cell lineages essential for constructing hematopoietic tissues. Namely, the c-kit gene that is expressed in hematopoietic stem cells is flanked by pdgfr alpha and flk genes expressed respectively in stromal cells and vascular endothelial cells. In this article, we review our results on their expression in the embryonic hematopoietic tissues. We found that co-expression of Flkl and c-Kit was frequently detected either in vascular endothelial cells or hematopoietic cells in the early hematopoietic tissues. On the other hand, the three RTKPs are expressed in different cell lineages in the fetal liver. On the basis of this finding, we propose two modes of embryonic hematopoiesis; hematogenic angiopoiesis and hematopoiesis.     

Patient education for discharge after coronary bypass surgery in the 1990s: are patients adequately prepared?

Short hospitalizations for patients undergoing coronary artery bypass grafting (CABG) require continuous nursing evaluation of patients' discharge education. Six institutions collaborated in surveying 300 postoperative patients with CABG to identify learning priorities and patients' perceptions of the effectiveness of discharge education. Data analysis from the self-administered questionnaire demonstrated consistent patient priorities across institutions. Differences in teaching methods and content did not affect perceived preparedness or importance scores. Regional experience demonstrates that variable teaching efforts meet patients' priorities and provide high overall patient preparedness for discharge. Patients with the shortest hospitalizations had higher preparedness scores.     

Influence of Neotyphodium coenophialum on copper concentration in tall fescue

Poor performance of livestock that graze tall fescue (Festuca arundinacea Schreb.) has been associated with the endophyte fungus Neotyphodium coenophialum [Morgan-Jones and Gams] Glenn, Bacon, and Hanlin). Recent evidence suggests lowered Cu status and a depression of Cu-related immune function in steers that graze endophyte-infected (E+) tall fescue. Greenhouse and field studies investigated relationships between the endophyte and Cu concentrations in tall fescue. Seventeen infected 'Kenhy' clones were divided, and one plant of each pair was treated three times with Benomyl to remove the endophyte (E-). Plants were watered with nutrient solution in a greenhouse for 6 mo before sampling. Copper concentrations were greater (P < .001) in E- than in E+ clones (3.4 vs 2.8 microg/g; SE, .06). In the second greenhouse experiment, genetically similar E+ and E- 'Kentucky'-31 (KY-31) and 'Georgia Jessup' were grown from seed and fertilized with nutrient solution to produce mature plants. Copper concentrations were higher (P < .05) in E- than in E+ tall fescue (8.6 vs 7.6 microg/g; SE, .3). In a field plot experiment in Texas, E+ and E- KY-31 were grown with 0, 50, and 100% replacement of potential evapotranspiration. By September, Cu concentrations were higher (P < .05) in E- than in E+ tall fescue (7.3 vs 6.6 microg/g; SE, .2). In pasture experiments, KY-31 E+ (> 70% infection level) and E- (< 5% infection level) tall fescue were grown in Virginia at two locations with three rates of N fertilizer. Copper concentrations were higher (P < .05) in E- than in E+ tall fescue (4.8 vs 4.5 microg/g; SE, .1) and increased (P < .01) linearly in response to N. Our data demonstrate that the presence of the endophyte is associated with lower Cu concentrations in tall fescue, which may contribute to lowered Cu status in animals and thus contribute to the etiology of fescue toxicity.     

The effect of insulin on the function of the lysosomal apparatus of the neutrophilic leukocytes during the formation of a stress syndrome

In experiments on male rabbits with the lack of insulin it is been revealed violations after the past immobilization the intensivity and duration of neutrophilic leukocytosis decrease, contents of lysosomes in neutrophils, activity of acid phosphatase. By lysosomal ferments don't determine the can observer discordance of processes of coagulation, fibrinolysis, kininogenesis.     

Process Requirements for Cost-Effective Precision Grinding

Costs in precision cylindrical grinding are compared for different abrasives, machines and grinding conditions. The analysis is for repeated batch production. Account is taken of machine cost and abrasive cost. Cost comparisons were based on extensive trials to assess re-dress life against workpiece quality requirements. Experiments show that different workpiece materials require different strategies to reduce costs. Easy-to-grind AISI 52100 and difficult-to-grind Inconel 718 materials were ground at conventional speeds and at high speeds. It is shown that wheel speed affects production rate through acceptable values of re-dress life, removal rate and dwell time. Advantages were gained using vitrified CBN at conventional speed and at high speed. For both materials, vitrified CBN wheels used at high speed, gave better quality at lower cost than conventional abrasives. Wheel costs became negligible and labour costs greatly reduced. Re-dress life trials, usually neglected, are shown to be essential to reduce costs and maintain quality [1].     

The inverse oxidation phenomenon

The oxidation rate of some “as manufactured” graphites increases with increased distance from the surface. The preponderance of the data supports the conclusion that this phenomenon is due to increased catalytic activity of one or more of the impurities in the graphite, and that the increase in catalytic activity is due to changes in the chemical state of the impurities.