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Nelson CD, Reinhardt TA, Thacker TC, Beitz DC, Lippolis JD. Modulation of the bovine innate immune response by production of 1alpha,25-dihydroxyvitamin D(3) in bovine monocytes. J Dairy Sci 2010; 93:1041-9. [PMID: 20172224 DOI: 10.3168/jds.2009-2663] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Accepted: 11/30/2009] [Indexed: 01/18/2023]
Abstract
In cattle, the kidney has been the only known site for production of 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] from 25-hydroxyvitamin D(3) [25(OH)D(3)] by 1alpha-hydroxylase (1alpha-OHase). Based on human studies, it was hypothesized that bovine monocytes could produce 1,25(OH)(2)D(3) upon activation and 1,25(OH)(2)D(3) would regulate expression of vitamin D-responsive genes in monocytes. First, the effects of 1,25(OH)(2)D(3) on bovine monocytes isolated from peripheral blood were tested. Treatment of nonstimulated monocytes with 1,25(OH)(2)D(3) increased expression of the gene for the vitamin D 24-hydroxylase (24-OHase) enzyme by 51+/-13 fold, but 1,25(OH)(2)D(3) induction of 24-OHase expression was blocked by lipopolysaccharide (LPS) stimulation. In addition, 1,25(OH)(2)D(3) increased the gene expression of inducible nitric oxide synthase and the chemokine RANTES (regulated upon activation, normal T-cell expressed and secreted) in LPS-stimulated monocytes 69+/-13 and 40+/-12 fold, respectively. Next, the ability of bovine monocytes to express 1alpha-OHase and produce 1,25(OH)(2)D(3) was tested. Activation of monocytes with LPS, tripalmitoylated lipopeptide (Pam3CSK4), or peptidoglycan caused 43+/-9, 17+/-3, and 19+/-3 fold increases in 1alpha-OHase gene expression, respectively. Addition of 25(OH)D(3) to LPS-stimulated monocytes enhanced expression of inducible nitric oxide synthase and RANTES and nitric oxide production in a dose-dependent manner, giving evidence that activated monocytes convert 25(OH)D(3) to 1,25(OH)(2)D(3). In conclusion, bovine monocytes produce 1,25(OH)(2)D(3) in response to toll-like receptor signaling, and 1,25(OH)(2)D(3) production in monocytes increased the expression of genes involved in the innate immune system. Vitamin D status of cattle might be important for optimal innate immune function because 1,25(OH)(2)D(3) production in activated monocytes and subsequent upregulation of inducible nitric oxide synthase and RANTES expression was dependent on 25(OH)D(3) availability.
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Josserand SA, Potter KM, Echt CS, Nelson CD. Isolation and characterization of microsatellite markers for Carolina hemlock (Tsuga caroliniana). Mol Ecol Resour 2008; 8:1371-4. [PMID: 21586049 DOI: 10.1111/j.1755-0998.2008.02294.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We describe the isolation and characterization of 31 polymorphic di- and trinucleotide microsatellite marker loci for Carolina hemlock (Tsuga caroliniana Englem.). In addition, primer pairs for 16 loci amplified scoreable alleles in six other Tsuga species. In eastern North America, both Carolina hemlock and eastern hemlock (Tsuga canadensis [L.] Carr.) populations are declining due to infestation by hemlock woolly adelgid, Adelges tsugae. The markers described here should enhance population genetic studies of hemlocks, providing valuable information for conserving and restoring these important forest tree species.
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Nelson CD, Weng C, Kubisiak TL, Stine M, Brown CL. On the Number of Genes Controlling the Grass Stage in Longleaf Pine. J Hered 2003; 94:392-8. [PMID: 14557392 DOI: 10.1093/jhered/esg086] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The grass stage is an inherent and distinctive developmental trait of longleaf pine (Pinus palustris), in which height growth in the first few years after germination is suppressed. In operational forestry practice the grass stage extends for two to several years and often plays a role in planting failures and decisions to plant alternative species. Interspecies hybrids involving loblolly (P. taeda) and slash (P. elliottii var. elliottii) pines have been investigated as a means to produce planting stock with improved early height growth and to develop backcross populations for advanced generation breeding. We have reevaluated data from several interspecies populations, with the objective of estimating the number of genes contributing to the difference in first-year height growth between longleaf and loblolly pines. Estimates based on means and variances of parental and interspecies hybrid and backcross families suggest a minimum of 4 to 10 genes with standard errors less than half the estimates. These results suggest that the grass stage has evolved through the accumulation of alleles at several loci, each with small effects on various components of first-year height growth. Given the complexity of the grass-stage trait, tree breeders may need to combine genetic marker analysis with recurrent backcross breeding to efficiently develop longleaf pine planting stock for improved reforestation.
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Mein EA, Greenman PE, McMillin DL, Richards DG, Nelson CD. Manual medicine diversity: research pitfalls and the emerging medical paradigm. THE JOURNAL OF THE AMERICAN OSTEOPATHIC ASSOCIATION 2001; 101:441-4. [PMID: 11526876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Recent studies published in leading medical journals have concluded that chiropractic treatment is not particularly helpful for relieving asthma and migraine symptoms because even though study participants showed notable improvement in symptoms, those subjects who received sham manual medicine treatments also showed improvement. Yet the sham treatment received by control groups in these studies is reminiscent in many ways of traditional osteopathic manipulation. This seems to represent not only a failure to recognize the value of many manual medicine techniques but also an ignorance of the broad spectrum of manual medicine techniques used by various practitioners, from osteopathic physicians to chiropractors to physical therapists. Such blind spots compromise research methodology with regard to manual medicine studies, which could, in turn, diminish the role of manual medicine in clinical practice. Osteopathic manipulative treatment provides an excellent model for recognizing and integrating the full range of manual medicine techniques into research and clinical applications because of the wide range of techniques employed. The potential exists for these techniques to contribute much to medical research and clinical practice--provided that osteopathic physicians and other manual medicine practitioners work to alleviate ignorance about the efficacy of various forms of manipulation.
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Sheriff DD, Isdahl WM, Nelson CD, Werchan PM. Brief exposure to -Gz reduces cerebral perfusion pressure during subsequent +Gz stress in rats. AVIATION, SPACE, AND ENVIRONMENTAL MEDICINE 2001; 72:8-12. [PMID: 11194999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
INTRODUCTION In humans, +Gz exposure immediately preceded by exposure to zero or -Gz can result in unexpected incapacitation ("push-pull" effect). Our goals were to establish whether this phenomenon exists in rats and to evaluate the importance of varying the duration of -Gz exposure on magnitude of the push-pull effect on cerebral perfusion pressure. METHODS Eight conscious male rats were studied in the transition from +5 Gz to +10 Gz imposed by centrifugation. This was done with (push-pull) or without (control) 2 s exposure to -5 Gz applied using a counterbalanced design. Seven isoflurane anesthetized rats were studied in the transition from 0Gz (+1Gy) to + 1Gz imposed by tilting. This was done with (push-pull) or without (control) 0.5, 1, 3, or 9 s exposure to -1Gz imposed immediately prior to the transition applied using a counterbalanced designed. RESULTS Exposure to 2 s of -5 Gz significantly (p < 0.01) reduced carotid artery pressure in the 4th through 8th s of exposure to +10 Gz by an average of 15 mmHg compared with control. In the tilt experiments, a push-pull effect was found with mild Gz exposure (+/-1Gz) with as little as 0.5 s -Gz exposure. Varying the head-down dwell time did not alter the magnitude of the exaggerated hypotension induced by "push-pull" (p = 0.90). CONCLUSIONS We conclude that rats express a "push-pull" effect similar to that observed in humans but that altering the duration of exposure to -Gz does not influence the magnitude of the "push-pull" effect.
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Nelson CD, Spear RN, Andrews JH. Automated image analysis of live/dead staining of the fungus Aureobasidium pullulans on microscope slides and leaf surfaces. Biotechniques 2000; 29:874-80, 882. [PMID: 11056819 DOI: 10.2144/00294rr04] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
An image analysis program and protocol for the identification and enumeration of live versus dead cells of the yeast-like fungus Aureobasidium pullulans was developed for both populations on microscope slides and leaf surfaces. Live cells took up CellTracker Blue, while nonviable cells stained with DEAD Red. Image analysis macro programs running under Optimas software were used to acquire images and to differentiate and enumerate viable from nonviable cells. The software was capable of discriminating green as a third parameter for identification and quantification of green fluorescent protein-expressing cells in a wild-type population.
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Sheriff DD, Nelson CD, Sundermann RK. Does autonomic blockade reveal a potent contribution of nitric oxide to locomotion-induced vasodilation? Am J Physiol Heart Circ Physiol 2000; 279:H726-32. [PMID: 10924072 DOI: 10.1152/ajpheart.2000.279.2.h726] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We sought to test the role of nitric oxide (NO) in governing skeletal muscle (iliac) vascular conductance during treadmill locomotion in dogs (n = 6; 3.2 and 6.4 km/h at 0% grade, and 6.4 km/h at 10% grade). As seen previously, the increase in muscle vascular conductance accompanying treadmill locomotion was little influenced by NO synthase inhibition alone with N(omega)-nitro-L-arginine methyl ester (L-NAME, 10 mg/kg iv), but the absolute value of conductance achieved during locomotion was reduced. Such ambiguous results provide an unclear picture regarding the importance of NO during locomotion. However, muscle vasodilation is normally restrained by the sympathetic system during locomotion. Thus a significant contribution by NO to the increase in vascular conductance that accompanies locomotion could be masked by partial withdrawal of the competing influence of sympathetic vasoconstrictor nerve activity secondary to the rise in arterial pressure following systemic L-NAME administration. To test this possibility, we compared the rise in muscle vascular conductance before and after L-NAME treatment while ganglionic transmission was blocked by hexamethonium. Under these conditions, L-NAME significantly reduced both the rise in vascular conductance (by 32%, P < 0.001) and the absolute level of vascular conductance (by 30%, P < 0.001) achieved during locomotion with no effect on blood flow. Thus augmented NO production normally provides a significant drive to relax vascular smooth muscle in active skeletal muscle during locomotion. Potential deficits stemming from the absence of NO following L-NAME treatment are masked by less intense sympathetic restraint when autonomic function is intact.
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Mcmillin DL, Richards DG, Mein EA, Nelson CD. Systemic aspects of psoriasis. An integrative model based on intestinal etiology. INTEGRATIVE MEDICINE : INTEGRATING CONVENTIONAL AND ALTERNATIVE MEDICINE 2000; 2:105-113. [PMID: 10882884 DOI: 10.1016/s1096-2190(00)00010-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Psoriasis can best be understood from a multifactorial approach that recognizes the systemic aspects of the disorder. Among the various factors thought to be involved in the etiology and pathogenesis of psoriasis, bowel pathology has assumed a noteworthy position in the literature. This article reviews the psoriasis/bowel connection with regard to abnormal bowel structure and physiology in psoriasis patients. Clinical implications of bowel involvement in psoriasis are discussed within the framework of an integrative medicine model that emphasizes natural therapeutics for addressing the systemic aspects of the illness.
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Nelson CD, McMillin DL, Richards DG, Mein EA, Redwood D. Manual healing diversity and other challenges to chiropractic integration. J Manipulative Physiol Ther 2000; 23:202-7. [PMID: 10771505 DOI: 10.1016/s0161-4754(00)90250-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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McMillin DL, Richards DG, Mein EA, Nelson CD. The abdominal brain and enteric nervous system. J Altern Complement Med 1999; 5:575-86. [PMID: 10630351 DOI: 10.1089/acm.1999.5.575] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Conventional medical treatment for neurologic disorders such as epilepsy, migraine, and autism focuses on the brain. Although standard medical treatment is often helpful, the underlying causes of these disorders are not well understood. Furthermore, some individuals respond poorly or not at all to regular medicine. Evidence is accumulating in the medical literature that the enteric nervous system (ENS)-that part of the nervous system associated with the alimentary canal-also plays a role in these disorders. Historically, the concept of an autonomous abdominal nervous system was advocated by Byron Robinson, Johannis Langley, and Edgar Cayce. The work of these three prominent historical figures is considered along with modem view-points on the abdominal nervous system. Complementary therapies that address the nervous system of the abdomen have potential as useful adjuncts to conventional treatment for certain neurologic disorders.
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Stelzer HE, Doudrick RL, Kubisiak TL, Nelson CD. Prescreening Slash Pine and Cronartium Pedigrees for Evaluation of Complementary Gene Action in Fusiform Rust Disease. PLANT DISEASE 1999; 83:385-389. [PMID: 30845592 DOI: 10.1094/pdis.1999.83.4.385] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Single-urediniospore cultures of the fusiform rust fungus were used to inoculate seedlings from 10 full-sib families of a five-parent slash pine diallel at two different times in 1994. The presence or absence of fusiform rust galls was recorded for each inoculated seedling at 9 months postinoculation, and percent infection levels for each family-inoculum-time combination were used for detecting differences among host families and fungal cultures and for identifying differential interactions. The existence of differential interactions between two or more fungal cultures and two or more host families verifies that complementary gene action does exist in this pathosystem. Some host families may be excluded from more detailed interaction studies on the basis of their redundancy and lack of participation in differential interactions.
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Richards DG, Mein EA, Nelson CD. Chiropractic manipulation for childhood asthma. N Engl J Med 1999; 340:391-2. [PMID: 9988611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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Kubisiak TL, Hebard FV, Nelson CD, Zhang J, Bernatzky R, Huang H, Anagnostakis SL, Doudrick RL. Molecular mapping of resistance to blight in an interspecific cross in the genus castanea. PHYTOPATHOLOGY 1997; 87:751-9. [PMID: 18945098 DOI: 10.1094/phyto.1997.87.7.751] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
ABSTRACT A three-generation American chestnut x Chinese chestnut pedigree was used to construct a genetic linkage map for chestnut and to investigate the control of resistance to Endothia parasitica (chestnut blight fungus). DNA genotypes for 241 polymorphic markers (eight isozymes, 17 restriction fragment length polymorphisms [RFLPs], and 216 random amplified polymorphic DNAs [RAPDs]) were assayed on an F(2) family consisting of 102 individuals. Of these markers, 196 were segregating as expected and, subsequently, used for primary linkage mapping. Two isozymes, 12 RFLPs, and 170 RAPDs were mapped to 12 linkage groups spanning a total genetic distance of 530.1 Kosambi centimorgans. F(2) plants were evaluated for a response to E. parasitica infection by directly inoculating them with two unique fungal isolates and measuring canker expansion over a period of 3.5 months. Results were compared with the marker genotype data, thereby identifying genomic regions significantly associated with a resistance response. Single-marker or nonsimultaneous analyses of variance identified seven genomic regions that appear to have an effect on host response. Multiple-marker or simultaneous models suggest that three of these regions have a significant effect on host response, together explaining as much as 42.2% of the total variation for canker size. At each of the three putative resistance loci, alleles derived from the Chinese chestnut grandparent were associated with smaller canker size, or higher levels of resistance.
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Doudrick RL, Heslop-Harrison JS, Nelson CD, Schmidt T, Nance WL, Schwarzacher T. Karyotype of Slash Pine (Pinus elliottii var. elliottii) Using Patterns of Fluorescence in situ Hybridization and Fluorochrome Banding. J Hered 1995. [DOI: 10.1093/oxfordjournals.jhered.a111583] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Kubisiak TL, Nelson CD, Nance WL, Stine M. RAPD linkage mapping in a longleaf pine x slash pine F1 family. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 1995; 90:1119-27. [PMID: 24173072 DOI: 10.1007/bf00222931] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/1994] [Accepted: 09/30/1994] [Indexed: 05/14/2023]
Abstract
Random amplified polymorphic DNAs (RAPDs) were used to construct linkage maps of the parent of a longleaf pine (Pinus palustris Mill.) slash pine (Pinus elliottii Englm.) F1 family. A total of 247 segregating loci [233 (1∶1), 14 (3∶1)] and 87 polymorphic (between parents), but non-segregating, loci were identified. The 233 loci segregating 1∶1 (testcross configuration) were used to construct parent-specific linkage maps, 132 for the longleaf-pine parent and 101 for the slash-pine parent. The resulting linkage maps consisted of 122 marker loci in 18 groups (three or more loci) and three pairs (1367.5 cM) for longleaf pine, and 91 marker loci in 13 groups and six pairs for slash pine (952.9 cM). Genome size estimates based on two-point linkage data ranged from 2348 to 2392 cM for longleaf pine, and from 2292 to 2372 cM for slash pine. Linkage of 3∶1 loci to testcross loci in each of the parental maps was used to infer further linkages within maps, as well as potentially homologous counterparts between maps. Three of the longleaf-pine linkage groups appear to be potentially homologous counterparts to four different slash-pine linkage groups. The number of heterozygous loci (previously testcross in parents) per F1 individual, ranged from 96 to 130. With the 87 polymorphic, but non-segregating, loci that should also be heterozygous in the F1 progeny, a maximum of 183-217 heterozygous loci could be available for mapping early height growth (EHG) loci and for applying genomic selection in backcross populations.
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Nelson CD, Kubisiak TL, Stine M, Nance WL. A Genetic Linkage Map of Longleaf Pine (Pinus palustris Mill.) Based on Random Amplified Polymorphic DNAs. J Hered 1994. [DOI: 10.1093/oxfordjournals.jhered.a111497] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Doudrick RL, Nelson CD, Nance WL. Genetic Analysis of a Single Urediniospore Culture of Cronartium Quercuum f. sp. fusiforme, Using Random Amplified Polymorphic DNA Markers. Mycologia 1993. [DOI: 10.2307/3760673] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Nelson CD, Nance WL, Doudrick RL. A partial genetic linkage map of slash pine (Pinus elliottii Engelm. var. elliottii) based on random amplified polymorphic DNAs. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 1993; 87:145-151. [PMID: 24190206 DOI: 10.1007/bf00223758] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/1992] [Accepted: 03/12/1993] [Indexed: 06/02/2023]
Abstract
A set of 420 random, 10-base, oligonucleotide primers was screened for random amplified polymorphic DNA (RAPD) fragments within a sample of eight megagametophyte DNAs of a single slash pine (Pinus elliottii Engelm. var. elliottii) tree. The apparently repeatable RAPD fragments were further characterized within a sample of 68 megagametophytes from the same tree. Fragments segregating in a 1∶1, present-to-absent, ratio were classified and mapped using multi-point linkage analysis. The analysis revealed 13 linkage groups of at least three loci, ranging in size from 28 to 68 cM, and nine linked pairs of loci. The 22 groups and pairs included 73 RAPD markers and covered a genetic map distance of approximately 782 cM. Genome size estimates, based on linkage data, ranged from 2880 to 3360 cM. Using a 30-cM map scale and including the 24 unlinked markers and the ends of the 13 linkage groups and nine linked pairs, the set of RAPD markers accounts for approximately 2160 cM or 64-75% of the genome. This extent of genomic coverage should allow for the efficient mapping of genes responsible for a reaction to the causal agent of fusiform rust disease, Cronartium quercuum (Berk.) Miyabe ex Shirai f. sp. fusiforme.
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Nelson CD, Waggoner DD, Donnell GN, Tuerck JM, Buist NR. Verbal dyspraxia in treated galactosemia. Pediatrics 1991; 88:346-50. [PMID: 1861938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Galactosemia is an inborn error of metabolism that causes life-threatening illness a few days after galactose-containing milk is fed to a newborn. Early treatment with a strict lactose-free diet results in rapid improvement, and, until recently, it was thought that the long-term prognosis in such infants was usually good. The speech characteristics of 24 patients treated for galactosemia were examined. Fifty-four percent had the specific speech disorder, verbal dyspraxia. This finding was not related to age at diagnosis, severity of symptoms in the newborn period, or to biochemical control. There may be, however, a relation between dyspraxia and diminished IQ scores observed in the group of patients with dyspraxia judged as "severe." The findings indicate the association of a specific and unusual speech defect with a specific and rare metabolic disorder.
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Nelson CD, Glatz CE. Primary particle formation in protein precipitation. Biotechnol Bioeng 1985; 27:1434-44. [DOI: 10.1002/bit.260271007] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Penny P, Nelson CD. Movement within leaves and plants of 14C applied as 14CO2. ACTA ACUST UNITED AC 1970. [DOI: 10.1139/b70-148] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A study was carried out to determine how 14C applied as 14CO2 to a localized area of the leaf for 5 min moved to the rest of the leaf during the treatment period. It was concluded that 14CO2 diffuses from the application area to the rest of the leaf where it is fixed photosynthetically in the position detected by whole leaf autoradiography. These conclusions were deduced from experiments on darkening a portion of the leaf, comparing the radioactive compounds in treated and untreated areas of the leaf, and by using variegated Pelargonium leaves. Using the darkening technique, 14CO2 movement in the stem of soybean was not detected for 15 min after treatment of a primary leaf with 14CO2 in the light.
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Hofstra G, Nelson CD. The translocation of photosynthetically assimilated 14C in corn. ACTA ACUST UNITED AC 1969. [DOI: 10.1139/b69-205] [Citation(s) in RCA: 48] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A detailed study was made of translocation of photosynthetically assimilated 14C in 3- to 6-week-old corn plants. Corn assimilated 14C via malate and aspartate, and incorporated most of the 14C into sucrose, the only translocation compound. Lowering the temperature from 26° to 8 °C delayed the incorporation of 14C into sucrose, but had no effect on the distribution of 14C among the intermediates. Recent 14C assimilate was translocated very rapidly from the fed area, the amount remaining in the fed area decreasing logarithmically with time. The translocate moved down the vascular bundle it entered in the fed area, with no detectable lateral movement. The logarithmic profile in the leaf blade appeared to be the result of a temporary accumulation of the labelled pulse in the separate vascular bundles. This accumulation of sucrose in the veins could be eliminated by cutting out the fed area. Between 80 and 90% of the assimilated 14C was translocated from the fed area of the leaf in 24 hours with 50% moved out in the first 30 minutes. Both the rate of translocation and the total amount moved out of the fed area increased as the temperature was changed over the range 7 to 26 °C. Each leaf of young corn plants both imported assimilates from and exported assimilates to all other parts of the plant.
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Hofstra G, Nelson CD. A comparative study of translocation of assimilated(14)C from leaves of different species. PLANTA 1969; 88:103-112. [PMID: 24504859 DOI: 10.1007/bf01391116] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/1969] [Indexed: 06/03/2023]
Abstract
Translocation of assimilated(14)C from the leaves of different species varied both in the rate of export and in the total percentage moved out. Those species which are known to have high photosynthetic rates, such as the tropical grasses sorghum and millet, exported 70% or more of the assimilated(14)C during the first 6 h after assimilation, compared to values of 45 to 50% for tomato, castor bean,Nicotiana affinis and soybean.The compounds in which the(14)C was retained in the leaves varied from species to species. Except for castor bean only small amounts were retained in sucrose, with generally much higher amounts in fructose, glucose and malic acid. Most of the(14)C was retained in the ethanol-insoluble fraction.
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Bulley NR, Nelson CD, Tregunna EB. Photosynthesis: action spectra for leaves in normal and low oxygen. PLANT PHYSIOLOGY 1969; 44:678-84. [PMID: 16657120 PMCID: PMC396145 DOI: 10.1104/pp.44.5.678] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The action spectrum of apparent photosynthesis for attached radish (Raphanus sativus L. var. Early Scarlet Globe) and corn (Zea mays L. var. Pride V.) leaves was measured at 300 mul/l CO(2) and both 21% and 2% O(2). The spectra were measured at light intensities where apparent photosynthesis was proportional to intensity. For radish, a high compensation point plant, oxygen had an inhibiting effect on photosynthesis at all wavelengths from 402 to 694 mmu. If a constant rate of photosynthesis at 21% O(2) for the different wavelengths was chosen, then the percent increase in net CO(2) fixation at 2% O(2) was constant. For corn, a low compensation point plant, no inhibitory effect of oxygen concentration from 2% to 21% O(2) was found over the visible spectrum. The CO(2) compensation point for light intensities greater than the light compensation point was found to be constant and independent of wavelength for both radish and corn leaves. For radish, the lowering of the oxygen concentration from 21% to 2% at these intensities was found to reduce the CO(2) compensation point by the same amount for the wavelengths studied.
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