Among the micronutrients required by humans, zinc has particularly divergent modes of action. cDNA microarray and quantitative PCR technologies were used to investigate the zinc responsiveness of known genes that influence zinc homeostasis and to identify, through global screening, genes that may relate to phenotypic outcomes of altered dietary zinc intake. Human monocytic͞ macrophage THP-1 cells were either acutely zinc depleted, using a cell-permeable zinc-specific chelator, or were supplemented with zinc to alter intracellular zinc concentrations. Initially, genes associated with zinc homeostasis were evaluated by quantitative PCR to establish ranges for fold changes in transcript abundance that might be expected with global screening. Zinc transporter-1 and zinc transporter-7 expression increased when cellular zinc increased, whereas Zip-2 expression, the most zinc-responsive gene examined, was markedly increased by zinc depletion. Microarrays composed of Ϸ22,000 elements were used to identify those genes responsive to either zinc depletion, zinc supplementation, or both conditions. Hierarchal clustering and ANOVA revealed that Ϸ5% or 1,045 genes were zinc responsive. Further sorting based on this pattern of the zinc responsiveness of these genes into seven groups revealed that 104 genes were linearly zinc responsive in a positive mode (i.e., increased expression as cellular zinc increases) and 86 genes that were linearly zinc responsive in a negative mode (i.e., decreased expression as cellular zinc increases). Expression of some genes was responsive to only zinc depletion or supplementation. Categorization by function revealed numerous genes needed for host defense were among those identified as zinc responsive, including cytokine receptors and genes associated with amplification of the Th1 immune response.nutrition ͉ genomics ͉ functional genomics ͉ immunology ͉ microarray

The mineralocorticoid aldosterone is a major regulator of Na+ and acid-base balance and control of blood pressure. Although the long-term effects of aldosterone have been extensively studied, the early aldosterone-responsive genes remain largely unknown. Using DNA array technology, we have characterized changes in gene expression after 1 h of exposure to aldosterone in a mouse inner medullary collecting duct cell line, mIMCD-3. Results from three independent microarray experiments revealed that the expression of many transcripts was affected by aldosterone treatment. Northern blot analysis confirmed the upregulation of four distinct transcripts identified by the microarray analysis, namely, the serum and glucose-regulated kinase sgk, connective tissue growth factor, period homolog, and preproendothelin. Immunoblot analysis for preproendothelin demonstrated increased protein expression. Following the levels of the four transcripts over time showed that each had a unique pattern of expression, suggesting that the cellular response to aldosterone is complex. The results presented here represent a novel list of early aldosterone-responsive transcripts and provide new avenues for elucidating the mechanism of acute aldosterone action in the kidney.

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(M.P.P.) As a step in developing an understanding of plant adaptation to low atmospheric pressures, we have identified genes central to the initial response of Arabidopsis to hypobaria. Exposure of plants to an atmosphere of 10 kPa compared with the sea-level pressure of 101 kPa resulted in the significant differential expression of more than 200 genes between the two treatments. Less than one-half of the genes induced by hypobaria are similarly affected by hypoxia, suggesting that response to hypobaria is unique and is more complex than an adaptation to the reduced partial pressure of oxygen inherent to hypobaric environments. In addition, the suites of genes induced by hypobaria confirm that water movement is a paramount issue at low atmospheric pressures, because many of gene products intersect abscisic acid-related, drought-induced pathways. A motivational constituent of these experiments is the need to address the National Aeronautics and Space Administration's plans to include plants as integral components of advanced life support systems. The design of bioregenerative life support systems seeks to maximize productivity within structures engineered to minimize mass and resource consumption. Currently, there are severe limitations to producing Earth-orbital, lunar, or Martian plant growth facilities that contain Earth-normal atmospheric pressures within light, transparent structures. However, some engineering limitations can be offset by growing plants in reduced atmospheric pressures. Characterization of the hypobaric response can therefore provide data to guide systems engineering development for bioregenerative life support, as well as lead to fundamental insights into aspects of desiccation metabolism and the means by which plants monitor water relations.Interest in the exploration of environments beyond Earth's atmosphere has brought unique challenges to bear on the understanding of the biological systems that will inhabit those environments. Among these challenges are alterations in atmospheric pressure, which are known to have effects on plant physiology and development (Mansell et al., 1968; Gale, 1973; Andre and Richaux, 1986;McKay and Toon, 1991; Andre and Massimino, 1992;Wheeler, 2000; He et al., 2003). Concepts for greenhouses on Mars, on the moon, and in Earth orbit incorporate low atmospheric pressures to address engineering and systems limitations (Boston, 1981; Drysdale, 2001).Historically, low-pressure environments have been used throughout the U.S. human space exploration programs to reduce the masses of structural and consumable components of space vehicles. Such reductions have resulted in increased mission lengths and/or increased masses of launched payloads. For example, the Mercury, Gemini, and Apollo environments were designed to operate at 34 kPa with a pure oxygen environment to simplify support of humans in space (Baker, 1981;Martin and McCormick, 1992). Skylab was also operated at 34 kPa (with a 70% O 2 /30% N 2 gas mixture), and that pressure was further reduced during period...

The pathophysiology of burning mouth syndrome (BMS) is largely unknown. Thus, the aim was to study oral mucosal blood flow in BMS-patients using laser Doppler flowmetry (LDF). Thirteen BMS patients (11 female, two male; mean age+/-SD 64.3+/-7.9 years, mean disease duration 18.9+/-6.2 months) and 13 healthy non-smoking controls matched for age and gender (11 female, two male; mean age 64.7+/-8.1 years) were investigated. Using the LDF technique mucosal blood flow (mBF) was measured at the hard palate, the tip of the tongue, on the midline of the oral vestibule, and on the lip. Measurements were made at rest and over 2 min following dry ice application of 10 s duration using a pencil shaped apparatus. In addition, blood pressure (BP), heart rate (HR), peripheral cutaneous blood flow, and transcutaneous pCO(2) were continuously recorded. Mucosal blood flow (mBF) increased at all measurement sites in response to dry ice application (P<0.001) with peak flow at 0.5--1.5 min after stimulation onset. During the following 1.5--2 min, blood flow decreased at all sites with a tendency to return to baseline towards the end of the observation period. Except for BP and peripheral blood flow, all of the cardiovascular changes exhibited significant changes during the observation period; no differences between groups were detected. When compared to healthy controls BMS patients generally exhibited larger changes in mBF. These changes were significant for recordings made on the hard palate (F[1,24]=13.9, P<0.001). Dry ice stimulation appears to be an effective, non-invasive and reasonably tolerable means to investigate mucosal blood flow at different mucosal sites. In general, vasoreactivity in BMS patients was higher than in healthy controls. BMS patients exhibited a higher response on the hard palate compared to controls. These changes in oral blood flow appear to be specifically related to BMS symptoms indicating a disturbed vasoreactivity.

Human immunodeficiency virus type 1 (HIV-1) impacts multiple lineages of hematopoietic cells, including lymphocytes and macrophages, either by direct infection or indirectly by perturbations of cell networks, leading to generalized immune deficiency. We designed a study to discover, in primary human macrophages, sentinel genetic targets that are impacted during replication over the course of 7 days by a CCR5-using virus. Expression of mRNA and proteins in virus-or mock-treated macrophages from multiple donors was evaluated. Hierarchical agglomerative cluster analysis grouped into distinct temporal expression patterns >900 known human genes that were induced or repressed at least fourfold by virus. Expression of more than one-third of the genes was induced rapidly by day 2 of infection, while other genes were induced at intermediate (day 4) or late (day 7) time points. More than 200 genes were expressed exclusively in either virus-or mock-treated macrophage cultures, independent of the donor, providing an unequivocal basis to distinguish an effect by virus. HIV-1 altered levels of mRNA and/or protein for diverse cellular programs in macrophages, including multiple genes that can contribute to a transition in the cell cycle from G 1 to G 2 /M, in contrast to expression in mock-treated macrophages of genes that maintain G 0 /G 1 . Virus treatment activated mediators of cell cycling, including PP2A, which is impacted by Vpr, as well as GADD45 and BRCA1, potentially novel targets for HIV-1. The results identify interrelated programs conducive to optimal HIV-1 replication and expression of genes that can contribute to macrophage dysfunction.

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Plots in 24 spruce-fir stands in northeastern Minnesota studied throughout the period 1957 to 1962 at the time of a spruce budworm outbreak were remeasured in 1979. Composition of the overstory changed from an average of 79% of the basal area in host species before to 31% after the budworm outbreak. Twelve percent of the stands showed growth in nonhost species that more than offset the loss in balsam fir and white spruce. The understory was minimally stocked with balsam fir in two-thirds of the stands. Only 4% of the regeneration was spruce. Even so, some well-established white spruce seedlings were found in two-thirds of the stands. Red maple was the most abundant hardwood invader. Raspberry, hazel and mountain maple were the principal shrub species limiting balsam fir reproduction Shrubs were most abundant in stands where balsam fir mortality had exceeded 80%. Half of the stands had seedlings that originated both before and after the outbreak; 45% had seedlings that originated only after the outbreak; and 5% had seedlings that originated only before the outbreak. Stands having moderate mixture of nonhost species in the over-story prior to the budworm outbreak had the most balsam fir regeneration. This resulted from seed produced by surviving balsam fir trees after the outbreak. Key words: Choristoneura fumiferana, Abies balsamea, Balsam fir, spruce-fir shrubs