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Chen S, Dickson DW, Kimbrough JW, McSorley R, Mitchell DJ. Fungi Associated with Females and Cysts of Heterodera glycines in a Florida Soybean Field. J Nematol 1994; 26:296-303. [PMID: 19279895 PMCID: PMC2619503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
Fungal colonization was determined for females and cysts of Heterodera glycines on soybean roots or in rhizosphere soil from a Florida soybean field. A total of 1,620 females and cysts were examined in 1991, and 1,303 were examined in 1992. More than 35 species of fungi were isolated from females and cysts. The frequency of fungi colonizing white and yellow females was low, but a high frequency of fungi was encountered in brown cysts, which increased with time of exposure of the cysts to the soil. No single fungal species predominated in the nematode females or cysts in this field. Rarely was a female or cyst colonized by more than one fungus. The common fungi isolated from the females and cysts were Neocosmospora vasinfecta, Fusarium solani, Fusarium oxysporum, Dictyochaeta coffeae, Dictyochaeta heteroderae, Pyrenochaeta terrestris, Exophiala pisciphila, Gliocladium catenulatum, Stagonospora heteroderae, and a black yeast-like fungus. The communities of common fungal species isolated from cysts in several regions in the southeastern United States appear to be similar.
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Snyder AW, Mitchell DJ, Chen Y. Spatial solitons of Maxwell's equations. OPTICS LETTERS 1994; 19:524-526. [PMID: 19844360 DOI: 10.1364/ol.19.000524] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Spatial solitons of Maxwell's equations propagating in an isotropic Kerr material differ significantly from the classical soliton of the nonlinear Schrödinger equation unless the electric field is linearly polarized along a geometric axis of the soliton intensity pattern. In general the polarization state changes continuously as the beam propagates, with a period of millimeters for highly nonlinear materials. This effect is due to the form birefringence of the soliton-induced waveguide. Equivalently, a soliton of Maxwell's equations is composed of both the TE and TM modes of the axially uniform waveguide it induces. Modal beating leads to the polarization dynamics.
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Lindsey JW, Hodgkinson S, Mehta R, Siegel RC, Mitchell DJ, Lim M, Piercy C, Tram T, Dorfman L, Enzmann D. Phase 1 clinical trial of chimeric monoclonal anti-CD4 antibody in multiple sclerosis. Neurology 1994; 44:413-9. [PMID: 8145907 DOI: 10.1212/wnl.44.3_part_1.413] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We conducted an open trial of cM-T412, a chimeric monoclonal anti-CD4 antibody, in 29 patients with MS. This antibody caused a prompt and long-lasting depletion of circulating CD4 (helper/inducer) lymphocytes. The mean (+/- SE) CD4 count for the group decreased from 870 (+/- 66) cells/mm3 at baseline to 76 (+/- 11) 3 hours after treatment, and then increased to 425 (+/- 38) at 1 month after treatment and 475 (+/- 39) at 6 months after treatment. Numbers of CD8 (cytotoxic/suppressor) lymphocytes, B lymphocytes, granulocytes, and monocytes changed transiently but showed no significant long-term effects. The most common side effects were headache, nausea, myalgia, fever, and tachycardia occurring in the first few hours after treatment. No serious or unexpected infections or other significant adverse effects occurred. Kurtzke EDSS scores remained stable, and MRI scans showed less contrast enhancement 1 week after treatment. We conclude that treatment of MS patients with cM-T412 chimeric anti-CD4 antibody is well tolerated at the doses tested and produces a long-lasting, selective depletion of CD4 lymphocytes.
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Snyder AW, Hewlett SJ, Mitchell DJ. Dynamic spatial solitons. PHYSICAL REVIEW LETTERS 1994; 72:1012-1015. [PMID: 10056595 DOI: 10.1103/physrevlett.72.1012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Shanley MS, Harrison A, Parales RE, Kowalchuk G, Mitchell DJ, Ornston LN. Unusual G + C content and codon usage in catIJF, a segment of the ben-cat supra-operonic cluster in the Acinetobacter calcoaceticus chromosome. Gene X 1994; 138:59-65. [PMID: 8125318 DOI: 10.1016/0378-1119(94)90783-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The nucleotide (nt) sequence of a 5.3-kb DNA segment containing the Gram- Acinetobacter calcoaceticus catBCIJFD operon is reported. This information completes determination of a 16-kb nt sequence containing the twelve ben and cat structural genes encoding enzymes required for catabolism of benzoate via the beta-ketoadipate pathway. Many of these genes can be traced to a common ancestry with genes from other organisms containing DNA with widely divergent G + C content. The A. calcoaceticus ben and cat genes are arranged in a supra-operonic cluster containing one known regulatory gene and three additional open reading frames (ORFs) that may have regulatory functions. Thirteen of the ben and cat genes, including the three ORFs with unknown function, are typical for A. calcoaceticus in that they possess a G + C content of 44.9 +/- 2.5%. Three exceptional A. calcoaceticus genes (catI, catJ and catF) possess G + C contents of 56.5 +/- 1.3%. These differences in G + C content are reflected in the distinctive patterns of codon usage shared by catI, catJ and catF. Thus, the catIJF region, known to exchange genetic information with the pcaIJF region in the same chromosome directing isofunctional proteins associated with the beta-ketoadipate pathway, has avoided the evolutionary forces that conferred characteristics G + C content upon the other ben and cat genes in A. calcoaceticus.
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Zamvil SS, al-Sabbagh A, Nelson PA, Kaul D, Charles MS, Mitchell DJ, Steinman L, Weiner HL, Kuchroo VK. 'Lupus-prone' mice are susceptible to organ-specific autoimmune disease, experimental allergic encephalomyelitis. Pathobiology 1994; 62:113-9. [PMID: 7524528 DOI: 10.1159/000163887] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Immunization with the multideterminant autoantigen myelin basic protein (MBP) causes experimental allergic encephalomyelitis (EAE), a T-cell-mediated autoimmune disease that serves as a model for multiple sclerosis (MS). MBP peptides Ac1-11 and p35-47 induce potent EAE in mice of the H-2u haplotype. T cells specific for Ac1-11 predominantly utilize one T-cell receptor (TCR) V beta gene segment, V beta 8.2. All T-cell clones and hybridomas analyzed, regardless of TCR V beta usage, utilize D beta 2 and J beta 2 elements. The NZW mouse strain (H-2z), which contributes to the spontaneous 'lupus-like' illness in (NZB x NZW)F1 mice, has a genomic deletion encompassing D beta 2 and J beta 2 gene segments. The NZW strain expresses class II (I-A and I-E) genes which share identical sequences with H-2u class II. We investigated whether these strains are susceptible to EAE induced with intact MBP and known encephalitogenic MBP peptides. In vitro analysis demonstrated that NZW antigen-presenting cells (APC) can present MBP and MBP peptide Ac1-11 to an encephalitogenic T-cell clone derived from an H-2u mouse, confirming the functional identity of NZW class-II (I-A) molecules with their respective H-2u class-II gene products. In vivo results demonstrated that NZW and (NZB x NZW)F1 mice are susceptible to EAE induced with intact MBP and Ac1-11. MBP p35-47 caused EAE in (NZB x NZW)F1 mice, which express alleles for both the normal (NZB) TCR beta-gene locus, and the abnormal (NZW) TCR beta-gene locus containing the J beta 2 deletion.(ABSTRACT TRUNCATED AT 250 WORDS)
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Monoclonal
- Encephalomyelitis, Autoimmune, Experimental/genetics
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Epitopes/genetics
- Epitopes/immunology
- Female
- Flow Cytometry
- H-2 Antigens
- Lupus Erythematosus, Systemic/genetics
- Lupus Erythematosus, Systemic/immunology
- Lymphocyte Activation
- Mice
- Mice, Mutant Strains
- Molecular Sequence Data
- Myelin Basic Protein
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- T-Lymphocytes/immunology
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Mitchell DJ. Toward a definition of Information Therapy. PROCEEDINGS. SYMPOSIUM ON COMPUTER APPLICATIONS IN MEDICAL CARE 1994:71-5. [PMID: 7950018 PMCID: PMC2247874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In these days of healthcare reform, there is an increasing need to control the costs of medical care. Preventive medical care can help by providing information to the patient, not only for illnesses, but for prevention and wellness. "Information Therapy" is a new term for supplying patients with health information, enabling them to make informed decisions about their health and care, participate in their own well-being, and thus decrease the utilization of healthcare resources. The formal definition for Information Therapy is presented and the basis for defining it lies in bibliotherapy, patient education, consumer health trends, patient's rights, and the Freedom of Information Act. The parameters and coverage of Information Therapy are discussed, the roles that Information Therapy can play in healthcare are explored, and the dual nature of its goals is presented. Barriers to its implementation are listed, however, the electronic age with its information superhighways is expected to provide a unique delivery system for Information Therapy.
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Chellemi DO, Olson SM, Scott JW, Mitchell DJ, McSorley R. Reduction of phytoparasitic nematodes on tomato by soil solarization and genotype. J Nematol 1993; 25:800-805. [PMID: 19279843 PMCID: PMC2619444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
The effects of soil solarization and tomato (Lycopersicon esculentum) genotype on populations of plant-parasitic nematodes and bacterial wilt were examined in North Florida. Maximum soil temperatures achieved under solarization treatments using a photoselective polyethylene mulch were 49.5, 46, and 40.5 C at depths of 5, 15, and 25 cm, respectively. Soil solarization reduced (P < 0.05) populations of Paratrichodorus minor, Rotylenchulus reniformis, and Criconemella spp. 85 days after transplanting on the cultivar Solar Set. Soil solarization reduced (P < 0.10) populations of P. minor, R. reniformis, and Criconemella spp. on the breeding line Fla. 7421. Reductions of P. minor and Criconemella spp. on Solar Set and Fla. 7421 were similar to those achieved by fumigation with a 67:33 mixture of methyl bromide and chloropicrin (448 kg/ha). Fla. 7421 reduced (P < 0.10) populations of R. reniformis compared with Solar Set. Neither soil solarization nor fumigation reduced the incidence of bacterial wilt on the susceptible cultivar Solar Set. This study demonstrates the ability of soil solarization to provide season-long control of plant-parasitic nematodes of tomato under a climatic regime characterized by periods of abundant rainfall and extended cloud cover.
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Himmel ME, Adney WS, Fox JW, Mitchell DJ, Baker JO. Isolation and characterization of two forms of beta-D-glucosidase from Aspergillus niger. Appl Biochem Biotechnol 1993; 39-40:213-25. [PMID: 8323261 DOI: 10.1007/bf02918991] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
beta-D-glucosidase purified from commercial preparations of clarified culture broth of Aspergillus niger (Novo SP188) was shown to elute as two distinct species during analytical anion-exchange chromatography (AEC). However, the two enzyme forms behaved identically on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE), high-performance size-exclusion chromatography (HPSEC), and isoelectric focusing. Also, the N-terminal amino acid sequence, amino acid composition, fingerprint of tryptic-digest peptides, circular dichroism spectra, and reaction kinetics appear identical for these forms. This feature of the A. niger enzyme is distinctly different from beta-D-glucosidase isozymes reported from other sources, where multiple forms tend to differ in molecular weight and/or isoelectric pH. Michaelis-Menten kinetic analysis also gave comparable results for the two forms. The distinct behavior on AEC was explained by considering the differences in N-linked carbohydrates liberated from both species following treatment with endoglycosidase H or F.
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Snyder AW, Mitchell DJ. Spatial solitons of the power-law nonlinearity. OPTICS LETTERS 1993; 18:101-103. [PMID: 19802051 DOI: 10.1364/ol.18.000101] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Simple, exact analytical solutions of Maxwell's equations are given for the TE-type self-guided modes of a medium that has a power-law dependence on intensity I(q) for the continuum values of q. An analytical criterion shows that such spatial solitons are stable for q < 2 only. Our derivation is novel in that solitons are borrowed from the known modes of the sech(2) profile (linear) waveguide, rather than by solving the nonlinear wave equation. The results reveal the change in soliton propagation as the nonlinear medium itself changes.
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Snyder AW, Poladian L, Mitchell DJ. Stable black self-guided beams of circular symmetry in a bulk Kerr medium. OPTICS LETTERS 1992; 17:789-791. [PMID: 19794632 DOI: 10.1364/ol.17.000789] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We demonstrate the existence of a stable black self-guided beam of circular symmetry in a bulk self-defocusing Kerr medium. There are no gray or higher-order self-guided beams of circular symmetry. The stability of black beams of circular symmetry is in sharp contrast to analogous bright beams in a self-focusing medium, which are unstable. Black self-guided beams are ideal for all-optical devices in bulk material as they can induce a single-mode optical fiber to guide a (weak) signal beam.
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Rivard CJ, Adney WS, Himmel ME, Mitchell DJ, Vinzant TB, Grohmann K, Moens L, Chum H. Effects of natural polymer acetylation on the anaerobic bioconversion to methane and carbon dioxide. Appl Biochem Biotechnol 1992. [DOI: 10.1007/bf02920592] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Snyder AW, Poladian L, Mitchell DJ. Self-tapered beams. OPTICS LETTERS 1992; 17:267-269. [PMID: 19784297 DOI: 10.1364/ol.17.000267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
By introducing material gain within a bulk nonlinear medium, it is possible to taper adiabatically a self-guided beam and to preserve its planar wave front. The amount of tapering can be controlled externally by varying the gain through the intensity of a pump beam. This self-guided beam induces a tapered (linear) waveguide, which in turn can guide a low-power (signal) beam. Two counterpropagating self-guided beams induce tapered, mismatched (linear) couplers that allow for all-optical, tunable, adiabatic power splitting without waveguide fabrication.
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Nitta T, Sato K, Allegretta M, Brocke S, Lim M, Mitchell DJ, Steinman L. Expression of granulocyte colony stimulating factor and granulocyte-macrophage colony stimulating factor genes in human astrocytoma cell lines and in glioma specimens. Brain Res 1992; 571:19-25. [PMID: 1377084 DOI: 10.1016/0006-8993(92)90505-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Expression of granulocyte (G) and granulocyte-macrophage (GM) colony stimulating factor (CSF) genes in human cells of astroglial lineage was studied. Primers for CSFs were used to analyze RNA transcripts in 5 cultured human astrocytoma cell lines and 8 fresh brain specimens by polymerase chain reaction. Constitutive expression of mRNA transcripts of GM-CSF could be detected in all astrocytoma and one neuroblastoma cell lines, and two out of 5 unstimulated astrocytomas, U87MG and U138 MG, expressed G-CSF genes. After stimulation with interleukin (IL)-1 beta + tumor necrosis factor (TNF)-alpha, all cell lines expressed G-CSF. In addition to the cultured cells, we examined gene expression within human malignant astrocytoma, peritumoral brain and autopsied normal brains. The results show that some of the tumor and its surrounding reactive lesions express G- and GM-CSF genes but normal brains do not. The concentration of G- and GM-CSF in supernatants of cultured cells was assessed at the protein level by ELISA. A low level of GM-CSF activity was constitutively present in all astrocytomas. G-CSF was detected in unstimulated U87MG and U138MG and other cell lines could synthesize G-CSF after the stimulation of IL-1 beta and TNF-alpha at the level of mRNA. Furthermore, the concentration of CSFs increased markedly upon stimulation with IL-1 beta and/or TNF-alpha in both a time- and dose-dependent fashion. From these results, it is suspected that astroglial cell-derived CSFs may participate in local immune reactions accompanying infection, degeneration and malignancies in the brain.
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Snyder AW, Poladian L, Mitchell DJ. Optically tunable adiabatic beam splitter. OPTICS LETTERS 1992; 17:118-120. [PMID: 19784248 DOI: 10.1364/ol.17.000118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Mitchell DJ, Wild SR, Jones KC. Arrested municipal solid waste incinerator fly ash as a source of heavy metals to the UK environment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 1992; 76:79-84. [PMID: 15092011 DOI: 10.1016/0269-7491(92)90119-u] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/1991] [Revised: 06/24/1991] [Accepted: 06/28/1991] [Indexed: 05/24/2023]
Abstract
Arrested fly ash samples from most currently operating municipal solid waste (MSW) incinerators in the UK have been analysed for a range of elements. Some of the more important heavy metals ranged in concentration as follows: Cd, 21-4646 (median = 271) mg kg(-1); Cu, 296-1307 (642) mg kg(-1); Cr, 44-1328 (574) mg kg(-1); Ni, 45-2204 (74) mg kg(-1); Pb, 447-9704 (4337) mg kg(-1); and Zn, 2285-13,500 (9232) mg kg(-1). These concentrations represent considerable enrichments relative to median UK soil concentrations. Enrichment ratios (defined as median fly ash: median UK soil) were as follows: Mn 1.6; Co 2.6; Ni 3.3; Ba 11; Sr 11; Cr 15; Cu 35; Pb 108; Zn 113; Cd 387. It is estimated that MSW incinerator ash contributes c. 15 t Cd and 241 t Pb to UK landfill sites per annum. These figures compare with previous studies by Hutton & Symon (Hutton, M. & Symon, C. (1986). The quantities of cadmium, lead, mercury and arsenic entering the UK environment from human activities. Sci. Total Environ., 57, 129-50.) which estimated that annual inputs to UK landfills from coal fly ash are c. 60 t Cd and 1270 t Pb. However, it is argued that metals associated with MSW ashes are potentially of greater environmental significance than in coal ashes, because they are much more available and present at much higher concentrations.
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Sakai K, Mitchell DJ, Tsukamoto T, Steinman L. Isolation of a complementary DNA clone encoding an autoantigen recognized by an anti-neuronal cell antibody from a patient with paraneoplastic cerebellar degeneration. Ann Neurol 1991; 30:738. [PMID: 1763903 DOI: 10.1002/ana.410300523] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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69
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Oostendorp M, Hewlett TE, Dickson DW, Mitchell DJ. Specific Gravity of Spores of Pasteuria penetrans and Extraction of Spore-filled Nematodes from Soil. J Nematol 1991; 23:729-732. [PMID: 19283193 PMCID: PMC2619215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
The specific gravity of spores of Pasteuria penetrans collected from Meloidogyne arenaria was found to be around 1.28. Increasing the sucrose concentration used for the extraction of Pratylenchus scribneri from a specific gravity of 1.14 to 1.26 led to the recovery of higher numbers of specimens filled with spores of Pasteuria sp. (P </= 0.05). The numbers of spore-filled specimens of Hoplolaimus galeatus recovered from field soil were not affected by the concentration of the sucrose solutions. Belonolaimus longicaudatus was recovered from field soil in greater numbers in sucrose solutions with specific gravities of 1.22 and 1.26 than with a specific gravity of 1.14 (P </= 0.05).
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Abraham S, Faulkin LJ, Mitchell DJ. Attenuation of mammary duct development by menhaden oil in BALB/c mice. PROCEEDINGS OF THE SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE. SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE (NEW YORK, N.Y.) 1991; 196:222-9. [PMID: 1990411 DOI: 10.3181/00379727-196-43184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The predominant polyunsaturated fatty acids of the n-6 family found in corn oil (CO) are crucial for normal mammary duct formation when fed to animals. However, as shown here, not all polyunsaturated fatty acids are equally effective in stimulating mammary gland development. The n-3 fatty acids in a 10% menhaden oil (MO) diet fed to mice effectively reduced both the diameter and the length of the growing mammary ducts. Previously, we demonstrated a similar reduction in duct growth by feeding a 10% fat diet high in those saturated fats found in hydrogenated cotton seed oil. The inhibited rate of duct maturation caused by hydrogenated cotton seed oil was reversed when the mice were allowed to mature on a diet containing n-6 fatty acids prior to feeding the saturated fat diet. The addition of 1% CO to a 9% hydrogenated cotton seed oil diet fed to immature mice was also sufficient to restore duct growth. Mice fed menhaden oil diets, on the other hand, continued to show impaired ductal growth well into adulthood. Examination of the ovaries from MO-fed mice as compared with CO-fed mice revealed significantly fewer corpora lutea. When exogenous progesterone was given to MO-fed mice, ductal growth was partially restored, but not to the extent seen in mice fed corn oil diets. Investigation of the fatty acid contents of livers of these mice revealed reduced amounts of arachidonate (20:4) in MO-fed mice when compared with CO-fed animals. The addition of 1% CO to the 9% MO diets did not alter the arachidonate content, indicating a block in the conversion of linoleate (18:2) to 20:4 by the n-3 fatty acids. Hence, dietary n-6 fatty acids are essential for normal mammary ductal development when fed prior to maturation. Although saturated rats are ineffective, n-3 fatty acids can partially substitute for the required n-6 fatty acids in both ductal and ovarian development.
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71
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Stockton BC, Mitchell DJ, Grohmann K, Himmel ME. Optimum?-D-glucosidase supplementation of cellulase for efficient conversion of cellulose to glucose. Biotechnol Lett 1991. [DOI: 10.1007/bf01033518] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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72
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Snyder AW, Mitchell DJ, Poladian L, Ladouceur F. Self-induced optical fibers: spatial solitary waves. OPTICS LETTERS 1991; 16:21-23. [PMID: 19773824 DOI: 10.1364/ol.16.000021] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
To be self-guided, a beam must exactly equal the mode of the linear-optical fiber that it induces. From this elementary consistency condition we can borrow solutions and their associated physics directly from the familiar literature of linear-optical waveguides. By considering a nonlinear medium characterized by ideal saturation, we present what is to our knowledge the first exact analytical solution of a two-dimensional self-guided beam. This beam is the familiar fundamental mode of a step-profile fiber. The stability of the beam is also determined.
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Oostendorp M, Dickson DW, Mitchell DJ. Population Development of Pasteuria penetrans on Meloidogyne arenaria. J Nematol 1991; 23:58-64. [PMID: 19283094 PMCID: PMC2619133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
A microplot study on the influence of cropping sequences with peanut in summer and bare fallowed or cover crops of rye or vetch in winter on the population development of Pasteuria penetrans was initiated in the spring of 1987. The number of spores of P. penetrans attached per second-stage juvenile of Meloidogyne arenaria race 1 increased from 0.11 in the fall of 1987 to 7.6, 8.6, and 3.6 in the fall of 1989 in the rye, vetch, and fallowed plots, respectively. Higher (P </= 0.05) levels of P. penetrans occurred in the rye and vetch plots than in fallowed plots. No influence of P. penetrans on peanut, rye, or vetch yield was observed in 1987 and 1988, but in 1989 peanut yield was 64% higher (P </= 0.05) in plots infested with P. penetrans than in plots without P. penetrans. Numbers of M. arenaria in plots without P. penetrans were influenced by the cropping sequences in the spring of 1988 and 1989 but not in the fall following the peanut crop. In the spring the plots with rye had the lowest nematode numbers in either year (P </= 0.05). Nematode numbers were lower (P </= 0.05) in plots with P. penetrans than in plots without P. penetrans in the spring of 1989 (vetch) and the fall of 1989 (rye, vetch, and fallowed).
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Sakai K, Mitchell DJ, Tsukamoto T, Steinman L. Isolation of a complementary DNA clone encoding an autoantigen recognized by an anti-neuronal cell antibody from a patient with paraneoplastic cerebellar degeneration. Ann Neurol 1990; 28:692-8. [PMID: 2260856 DOI: 10.1002/ana.410280515] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We isolated a complementary DNA clone encoding a 52-kd protein recognized by an anti-neuronal cell antibody in serum from a patient with paraneoplastic cerebellar degeneration associated with uterine carcinoma. The recombinant protein expressed in prokaryotic cells was specifically recognized by the anti-neuronal cell antibody from the patient, and its molecular weight was identical to that of antigenic proteins in the cerebellum. The deduced protein consisted of 450 amino acids dominated by hydrophilic residues, the calculated relative molecular mass was 51,238, and the predicted value of the isoelectric point was 4.99. This complementary DNA sequence and the deduced protein sequence have not been reported previously, and the sequences showed no homologies with the complimentary DNA or the amino acid sequences in the GenBank, EMBL, or NBRF databases, including the complementary DNA for a 34-kd cerebellar protein (CDR34) that is recognized by an anti-Purkinje cell antibody. Unexpectedly, the transcript of this gene was detected not only in the cerebellum and the brain stem but also in an extraneural tissue, the intestine.
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Oostendorp M, Dickson DW, Mitchell DJ. Host Range and Ecology of Isolates of Pasteuria spp. from the Southeastern United States. J Nematol 1990; 22:525-531. [PMID: 19287753 PMCID: PMC2619090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
Isolates of Pasteuria penetrans were evaluated for ecological characteristics that are important in determining their potential as biological control agents. Isolate P-20 survived without loss of its ability to attach to its host nematode in dry, moist, and wet soil and in soil wetted and dried repeatedly for 6 weeks. Some spores moved 6.4 cm (the maximum distance tested) downward in soil within 3 days with percolating water. The isolates varied greatly in their attachment to different nematode species and genera. Of five isolates tested in spore-infested soil, three (P-104, P-122, B-3) attached to two or more nematode species, whereas B-8 attached only to Meloidogyne hapla and B-I did not attach to any of the nematodes tested. In water suspensions, spores of isolate P-20 attached readily to M. arenaria but only a few spores attached to other Meloidogyne spp. Isolate P-104 attached to all Meloidogyne spp. tested but not to Pratylenchus scribneri. Isolate B-4 attached to all species of Meloidogyne and Pratylenchus tested, but the rate of attachment was relatively low. Isolate P-Z00 attached in high numbers to M. arenaria when spores were extracted from females of this nematode; when extracted from M. javanica females, fewer spores attached to M. arenaria than to M. javanica or M. incognita.
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