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Biomedical subjects

R Moore

Publications and source records attributed to R Moore.

At least 325 records · Page 18Linked to original sources
PubMed1987

Influence of microgravity on root-cap regeneration and the structure of columella cells in Zea mays.

We launched imbibed seeds and seedlings of Zea mays into outer space aboard the space shuttle Columbia to determine the influence of microgravity on 1) root-cap regeneration, and 2) the distribution of amyloplasts and endoplasmic reticulum (ER) in the putative statocytes (i.e., columella cells) of roots. Decapped roots grown on Earth completely regenerated their caps within 4.8 days after decapping, while those grown in microgravity did not regenerate caps. In Earth-grown seedlings, the ER was localized primarily along the periphery of columella cells, and amyloplasts sedimented in response to gravity to the lower sides of the cells. Seeds germinated on Earth and subsequently launched into outer space had a distribution of ER in columella cells similar to that of Earth-grown controls, but amyloplasts were distributed throughout the cells. Seeds germinated in outer space were characterized by the presence of spherical and ellipsoidal masses of ER and randomly distributed amyloplasts in their columella cells. These results indicate that 1) gravity is necessary for regeneration of the root cap, 2) columella cells can maintain their characteristic distribution of ER in microgravity only if they are exposed previously to gravity, and 3) gravity is necessary to distribute the ER in columella cells of this cultivar of Z. mays.

Endoplasmic Reticulum↗
PubMed1987

Myocardial damage delineated by indium-111 antimyosin Fab and technetium-99m pyrophosphate.

Technetium-99m-labeled pyrophosphate and radiolabeled antimyosin antibodies are two infarct localizing agents with apparently different kinetics of localization. To determine whether these agents localize in a similar fashion in early acute myocardial necrosis, we studied the simultaneous distribution of 111In-labeled antimyosin and 99mTc-labeled pyrophosphate in dogs after intracoronary (i.c.) (n = 9) or intravenous (i.v.) (n = 9) administration of a mixture of these two agents in a reperfused infarct model. The mean infarct size (+/- s.d.) delineated by pyrophosphate [20.2 +/- 14.1 (i.v.), 29.8 +/- 12.3 (i.c.)] was larger than that by antimyosin [14.2 +/- 11.3 (i.v.) (p = 0.05), 20.0 +/- 11.8 (i.c.) (p = 0.05)] which was larger than that by triphenyl tetrazolium chloride [13.9 +/- 8.0 (i.v.) (p = 0.05), 15.3 +/- 6.5 (i.c.) (p = 0.05)]. This overestimation persisted whether the radiopharmaceuticals were administered by intracoronary or intravenous injections, although the latter with antimyosin was only slightly larger (TTC:AM = 13.9:14.2) (p = n.s.). There was a good correlation, however, between antimyosin and pyrophosphate delineated infarct sizes in dogs with intracoronary injection (y = 0.82x + 13.33, r = 0.79) or i.v. injection (y = 1.208x + 3.01, r = 0.97) of the mixture of the two agents. Since the images of the 111In and 99mTc activities were obtained consecutively by identical methods, the overestimation of infarct size by pyrophosphate cannot be due to differences in spatial resolution of the techniques used. The differences in the areas of myocardial damage delineated by pyrophosphate and antimyosin in our study most probably denote the area of viable but compromised myocardium.

Animals↗
PubMed1987

Cardiovascular and acid-base effects of acetate and bicarbonate haemodialysis.

Cardiovascular and acid-base changes were studied in 18 adult haemodialysis patients during a single dialysis against acetate or bicarbonate dialysate. Tachycardia was significantly greater with acetate but, otherwise, blood pressure and peripheral resistance fell and cardiac output increased to a similar degree with the two types of dialysate. Arterial PCO2 increased with bicarbonate and fell slightly with acetate, while hypoxaemia was significantly worse during acetate dialysis. Arterial acetate concentrations increased in 2 of 12 patients during bicarbonate dialysis. No differences in patient symptomatology or hypotensive episodes were noted with acetate or bicarbonate. Any beneficial effects of bicarbonate dialysis are more likely to be related to preservation of arterial PO2 than to the absence of adverse cardiovascular effects of acetate.

Acetates↗
PubMed1986

Insertion elements and transitions in cloned mouse mammary tumour virus DNA: further delineation of the poison sequences.

The provirus of mouse mammary tumour virus (MMTV) is reputed to contain sequences within the viral gag gene that prevent or inhibit its propagation as a recombinant DNA clone in Escherichia coli. Here we report the successful isolation of several lambda and plasmid clones comprising the 5' virus-host DNA junction fragments from integrated MMTV proviruses in BR6 mice. Although the lambda clones appeared intact, almost all of the plasmids were found to contain the bacterial insertion sequences IS1 or IS2 within a small region of the gag gene. One nondisrupted clone was recovered which had undergone multiple G to A transitions, some of which created stop codons in gag. These results have provided more precise information as to the location of the poison sequences and are discussed in relation to possible explanations for the phenomenon.

Amino Acid Sequence↗
PubMed1986

Sequence, topography and protein coding potential of mouse int-2: a putative oncogene activated by mouse mammary tumour virus.

A major proportion of carcinomas induced by mouse mammary tumour virus (MMTV) show evidence for proviral activation of a cellular gene, int-2, on chromosome 7. The sequence of 7869 bp of DNA spanning the transcription unit of int-2 was determined and compared with that of a series of int-2-specific cDNA clones derived from mammary tumour RNA. The predicted positions of intron-exon boundaries, established by alignment of cDNA and chromosomal DNA sequences, indicate that the gene comprises at least three exons. An open reading frame capable of encoding a protein of 245 amino acids with an estimated mol. wt of 27 kd, is flanked by substantial non-coding segments at both 5' and 3' ends. Comparison of the chromosomal DNA sequence and the predicted amino acid sequence with available data-bases has revealed no homology to other known genes. These results are discussed in relation to the status of int-2 as a candidate proto-oncogene.

Amino Acid Sequence↗
PubMed1986

Molecular cloning and nucleotide sequence of a full-length cDNA for human alpha enolase.

We previously purified a 48-kDa protein (p48) that specifically reacts with an antiserum directed against the 12 carboxyl-terminal amino acids of the c-myc gene product. Using an antiserum directed against the purified p48, we have cloned a cDNA from a human expression library. This cDNA hybrid-selects an mRNA that translates to a 48-kDa protein that specifically reacts with anti-p48 serum. We have isolated a full-length cDNA that encodes p48 and spans 1755 bases. The coding region is 1299 bases long; 94 bases are 5' noncoding and 359 bases are 3' noncoding. The cDNA encodes a 433 amino acid protein that is 67% homologous to yeast enolase and 94% homologous to the rat non-neuronal enolase. The purified protein has been shown to have enolase activity and has been identified to be of the alpha type by isoenzyme analysis. The transcriptional regulation of enolase expression in response to mitogenic stimulation of peripheral blood lymphocytes and in response to heat shock is also discussed.

Amino Acid Sequence↗
PubMed1986

Cytochemical localization of calcium in cap cells of primary roots of Zea mays L.

The distribution of calcium (Ca) in caps of vertically- and horizontally-oriented roots of Zea mays was monitored to determine its possible role in root graviresponsiveness. A modification of the antimonate precipitation procedure was used to localize Ca in situ. In vertically-oriented roots, the presumed graviperceptive (i.e., columella) cells were characterized by minimal and symmetric staining of the plasmalemma and mitochondria. No precipitate was present in plasmodesmata or cell walls. Within 5 min after horizontal reorientation, staining was associated with the portion of the cell wall adjacent to the distal end of the cell. This asymmetric staining persisted throughout the onset of gravicurvature. No staining of lateral cell walls of columella cells was observed at any stage of gravicurvature, suggesting that a lateral flow of Ca through the columella tissue of horizontally-oriented roots does not occur. The outermost peripheral cells of roots oriented horizontally and vertically secrete Ca through plasmodesmata-like structures in their cell walls. These results are discussed relative to proposed roles of root-cap Ca in root gravicurvature.

Biological Transport↗
PubMed1986

A morphometric analysis of the redistribution of organelles in columella cells of horizontally-oriented roots of Zea mays.

In order to determine what structural changes in graviperceptive cells are associated with onset of root gravicurvature, the redistribution of organelles in columella cells of horizontally-oriented, graviresponding roots of Zea mays has been quantified. Root gravicurvature began by 15 min after reorientation, and did not involve significant changes in the (i) volume of individual columella cells or amyloplasts, (ii) relative volume of any cellular organelle, (iii) number of amyloplasts per columella cell, or (iv) surface area of cellular location of endoplasmic reticulum. Sedimentation of amyloplasts began within 1 to 2 min after reorientation, and was characterized by an intensely staining area of cytoplasm adjacent to the sedimenting amyloplasts. By 5 min after reorientation, amyloplasts were located in the lower distal corner of columella cells, and, by 15 min after reorientation, overlaid the entire length of the lower cell wall. No consistent contact between amyloplasts and any cellular structure was detected at any stage of gravicurvature. Centrally-located nuclei initially migrated upward in columella cells of horizontally-oriented roots, after which they moved to the proximal ends of the cells by 15 min after reorientation. No significant pattern of redistribution of vacuoles, mitochondria, dictyosomes, or hyaloplasm was detected that correlated with the onset of gravicurvature. These results indicate that amyloplasts and nuclei are the only organelles whose movements correlate positively with the onset of gravicurvature by primary roots of this cultivar of Zea mays.

Cell Nucleus↗
PubMed1986

The possible involvement of root-cap mucilage in gravitropism and calcium movement across root tips of Allium cepa L.

Roots of Allium cepa L. grown in aerated water elongate rapidly, but are not graviresponsive. These roots (1) possess extensive columella tissues comprised of cells containing numerous sedimented amyloplasts, (2) lack mucilage on their tips, and (3) are characterized by a weakly polar movement of calcium (Ca) across their tips. Placing roots in humid air correlates positively with the (1) onset of gravicurvature, (2) appearance of mucilage on tips of the roots, and (3) onset of the ability to transport Ca polarly to the lower side of the root tip. Gravicurvature of roots previously submerged in aerated water is more rapid when roots are oriented vertically for 1-2 h in humid air prior to being oriented horizontally. The more rapid gravicurvature of these roots correlates positively with the accumulation of mucilage at the tips of roots during the time the roots are oriented vertically. Therefore, the onset of gravicurvature and the ability of roots to transport Ca to the lower sides of their tips correlate positively with the presence of mucilage at their tips. These results suggest that mucilage may be important for the transport of Ca across root caps.

Allium↗
PubMed1986

The influence of gravity on the formation of amyloplasts in columella cells of Zea mays L.

Columella (i.e., putative graviperceptive) cells of Zea mays seedlings grown in the microgravity of outer space allocate significantly less volume to putative statoliths (amyloplasts) than do columella cells of Earth-grown seedlings. Amyloplasts of flight-grown seedlings are significantly smaller than those of ground controls, as is the average volume of individual starch grains. Similarly, the relative volume of starch in amyloplasts in columella cells of flight-grown seedlings is significantly less than that of Earth-grown seedlings. Microgravity does not significantly alter the volume of columella cells, the average number of amyloplasts per columella cell, or the number of starch grains per amyloplast. These results are discussed relative to the influence of gravity on cellular and organellar structure.

Gravitation↗
PubMed1986

Cultural perceptions of pain and pain coping among patients and dentists.

A combination of qualitative and quantitative methods were developed to describe pain and pain coping perceptions of 25 Chinese, 25 Anglo-Americans and 35 Scandinavians (54 patients and 21 dentists). Results revealed universal dimensions of pain such as time, intensity, location, quality, cause and curability. More culture-specific dimensions included the Chinese concept suantong, a multivariate concept of bone, muscle, joint, tooth and gingival pain. "Real" and "imagined" pains were mostly described by Western subjects, especially dentists; "imagined pain" being the conversion of fear or anxiety into perceived pain. These data indicate that the methods were sensitive to culture as a variable and indicate that ethnicity may play a stronger role in the perceptions of pain description than does professional socialization, but that professional socialization processes may have more influence on the perception of pain coping modes for this sample population.

Adaptation, Psychological↗
PubMed1986

Calcium-phospholipid enhanced protein phosphorylation in human placenta.

Calcium-activated, phospholipid-dependent protein phosphorylation has not been studied in placenta. Human placental cytosol was subjected to an endogenous protein phosphorylation assay using [gamma-32P]ATP in the presence of calcium and phosphatidylserine. Protein phosphorylation was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. When compared to basal levels, calcium (10(-6) M) in combination with phosphatidylserine (50 micrograms/ml) significantly enhanced (P less than 0.01) 32P incorporation into phosphoproteins having mol wt 47,000, 43,000, and 37,000. Half-maximal 32P incorporation was observed with 3.5 X 10(-7) M Ca2+ in the presence of phosphatidylserine (50 micrograms/ml). The effect of phosphatidylserine was biphasic. In the presence of Ca 10(-6) M, 32P incorporation increased to a maximum at 70 micrograms/ml of phosphatidylserine. The increase was suppressed at 150 micrograms/ml. Tetracaine caused a dose-dependent inhibition of calcium-activated, phospholipid-dependent enhancement of the three phosphorproteins. Calcium in the absence of phospholipid enhanced the phosphorylation of a protein of 98,000 mol wt. Phosphatidylserine suppressed this enhancement. Calmodulin (10(-6) M) had no detectable effect upon phosphorylation beyond that of calcium alone, but the calmodulin inhibitor R-24571 specificlly inhibited the calcium-stimulated 98,000 mol wt phosphoprotein. Calcium-activated, phospholipid-dependent phosphoproteins are present in human placental cytosol; whether calcium-activated, calmodulin-dependent phosphoproteins also are present remains a question.

Calcium↗
PubMed1986

How roots perceive and respond to gravity.

Graviperception by plant roots is believed to occur via the sedimentation of amyloplasts in columella cells of the root cap. This physical stimulus results in an accumulation of calcium on the lower side of the cap, which in turn induces gravicurvature. In this paper we present a model for root gravitropism integrating gravity-induced changes in electrical potential, cytochemical localization of calcium in cells of gravistimulated roots, and the interdependence of calcium and auxin movement. Key features of the model are that 1) gravity-induced redistribution of calcium is an early event in the transduction mechanism, and 2) apoplastic movement of calcium through the root-cap mucilage may be an important component of the pathway for calcium movement.

Abscisic Acid↗
PubMed1986

Development of primary and secondary immune responses to mouse monoclonal antibodies used in the diagnosis and therapy of malignant neoplasms.

Human anti-mouse immunoglobulin immune responses were studied in ten patients, eight with ovarian cancer and two with grade IV gliomas, diagnosed and treated with radiolabeled (123I, 131I) murine monoclonal antibodies. It was found that serum from these patients before treatment and from 18 control healthy individuals contained detectable antibodies to antigenic determinants on the Fc but not the F(ab')2 portion of mouse immunoglobulin. No change in this reactivity occurred after the initial (imaging) dose of monoclonal antibodies. However, repeated administration of mouse immunoglobulins for therapy resulted in an elevated immune response directed against determinants on both Fc and F(ab')2 regions of mouse immunoglobulin. This response contained increased levels of immunoglobulin M as well as immunoglobulin G and showed a marked prozone effect in our enzyme linked immunosorbent assay system. None of the immunized patients developed a detectable antiidiotypic response.

Animals↗