10 results on '"Brewer JC"'
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2. Empirical comparison of genomic and phenotypic selection for resistance to Fusarium ear rot and fumonisin contamination in maize.
- Author
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Butoto EN, Brewer JC, and Holland JB
- Subjects
- Genomics methods, Plant Breeding, Plant Diseases genetics, Zea mays genetics, Fumonisins, Fusarium physiology
- Abstract
Key Message: GS and PS performed similarly in improving resistance to FER and FUM content. With cheaper and faster genotyping methods, GS has the potential to be more efficient than PS. Fusarium verticillioides is a common maize (Zea mays L.) pathogen that causes Fusarium ear rot (FER) and produces the mycotoxin fumonisin (FUM). This study empirically compared phenotypic selection (PS) and genomic selection (GS) for improving FER and FUM resistance. Three intermating generations of recurrent GS were conducted in the same time frame and from a common base population as two generations of recurrent PS. Lines sampled from each PS and GS cycle were evaluated in three North Carolina environments in 2020. We observed similar cumulative responses to GS and PS, representing decreases of about 50% of mean FER and FUM compared to the base population. The first cycle of GS was more effective than later cycles. PS and GS both achieved about 70% of predicted total gain from selection for FER, but only about 26% of predicted gains for FUM, suggesting that heritability for FUM was overestimated. We observed a 20% decrease in genetic marker variation from PS and 30% decrease from GS. Our greatest challenge was our inability to quickly obtain dense and consistent set of marker genotypes across generations of GS. Practical implementation of GS in individual small-scale breeding programs will require cheaper and faster genotyping methods, and such technological advances will present opportunities to significantly optimize selection and mating schemes for future GS efforts beyond what we were able to achieve in this study., (© 2022. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)
- Published
- 2022
- Full Text
- View/download PDF
3. Serotonin and neuropeptides are both released by the HSN command neuron to initiate Caenorhabditis elegans egg laying.
- Author
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Brewer JC, Olson AC, Collins KM, and Koelle MR
- Subjects
- Acetylcholine genetics, Acetylcholine metabolism, Animals, Caenorhabditis elegans genetics, Caenorhabditis elegans physiology, Disorders of Sex Development genetics, Female, Male, Motor Neurons metabolism, Mutation, Neurotransmitter Agents genetics, Serotonergic Neurons metabolism, Signal Transduction, Behavior, Animal, Neuropeptides genetics, Oviposition genetics, Serotonin genetics
- Abstract
Neurons typically release both a small-molecule neurotransmitter and one or more neuropeptides, but how these two types of signal from the same neuron might act together remains largely obscure. For example, serotonergic neurons in mammalian brain express the neuropeptide Substance P, but it is unclear how this co-released neuropeptide might modulate serotonin signaling. We studied this issue in C. elegans, in which all serotonergic neurons express the neuropeptide NLP-3. The serotonergic Hermaphrodite Specific Neurons (HSNs) are command motor neurons within the egg-laying circuit which have been shown to release serotonin to initiate egg-laying behavior. We found that egg-laying defects in animals lacking serotonin were far milder than in animals lacking HSNs, suggesting that HSNs must release other signal(s) in addition to serotonin to stimulate egg laying. While null mutants for nlp-3 had only mild egg-laying defects, animals lacking both serotonin and NLP-3 had severe defects, similar to those of animals lacking HSNs. Optogenetic activation of HSNs induced egg laying in wild-type animals, and in mutant animals lacking either serotonin or NLP-3, but failed to induce egg laying in animals lacking both. We recorded calcium activity in the egg-laying muscles of animals lacking either serotonin, NLP-3, or both. The single mutants, and to a greater extent the double mutant, showed muscle activity that was uncoordinated and unable to expel eggs. Specifically, the vm2 muscles cells, which are direct postsynaptic targets of the HSN, failed to contract simultaneously with other egg-laying muscle cells. Our results show that the HSN neurons use serotonin and the neuropeptide NLP-3 as partially redundant co-transmitters that together stimulate and coordinate activity of the target cells onto which they are released., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2019
- Full Text
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4. Activity of the C. elegans egg-laying behavior circuit is controlled by competing activation and feedback inhibition.
- Author
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Collins KM, Bode A, Fernandez RW, Tanis JE, Brewer JC, Creamer MS, and Koelle MR
- Subjects
- Animals, Caenorhabditis elegans drug effects, Caenorhabditis elegans growth & development, Caenorhabditis elegans metabolism, Caenorhabditis elegans Proteins metabolism, Chloride Channels metabolism, Choline metabolism, Choline pharmacology, Female, Gene Expression Regulation, Locomotion, Motor Neurons cytology, Motor Neurons drug effects, Motor Neurons metabolism, Muscle Contraction drug effects, Muscle Contraction genetics, Optogenetics, Oviposition drug effects, Periodicity, Receptors, Biogenic Amine metabolism, Serotonin metabolism, Serotonin pharmacology, Sexual Behavior, Animal drug effects, Signal Transduction, Tyramine metabolism, Tyramine pharmacology, Caenorhabditis elegans genetics, Caenorhabditis elegans Proteins genetics, Chloride Channels genetics, Feedback, Physiological, Oviposition genetics, Receptors, Biogenic Amine genetics, Sexual Behavior, Animal physiology
- Abstract
Like many behaviors, Caenorhabditis elegans egg laying alternates between inactive and active states. To understand how the underlying neural circuit turns the behavior on and off, we optically recorded circuit activity in behaving animals while manipulating circuit function using mutations, optogenetics, and drugs. In the active state, the circuit shows rhythmic activity phased with the body bends of locomotion. The serotonergic HSN command neurons initiate the active state, but accumulation of unlaid eggs also promotes the active state independent of the HSNs. The cholinergic VC motor neurons slow locomotion during egg-laying muscle contraction and egg release. The uv1 neuroendocrine cells mechanically sense passage of eggs through the vulva and release tyramine to inhibit egg laying, in part via the LGC-55 tyramine-gated Cl
- channel on the HSNs. Our results identify discrete signals that entrain or detach the circuit from the locomotion central pattern generator to produce active and inactive states., Competing Interests: The authors declare that no competing interests exist.- Published
- 2016
- Full Text
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5. Process and Microstructure to Achieve Ultra-high Dielectric Constant in Ceramic-Polymer Composites.
- Author
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Zhang L, Shan X, Bass P, Tong Y, Rolin TD, Hill CW, Brewer JC, Tucker DS, and Cheng ZY
- Abstract
Influences of process conditions on microstructure and dielectric properties of ceramic-polymer composites are systematically studied using CaCu
3 Ti4 O12 (CCTO) as filler and P(VDF-TrFE) 55/45 mol.% copolymer as the matrix by combining solution-cast and hot-pressing processes. It is found that the dielectric constant of the composites can be significantly enhanced-up to about 10 times - by using proper processing conditions. The dielectric constant of the composites can reach more than 1,000 over a wide temperature range with a low loss (tan δ ~ 10-1 ). It is concluded that besides the dense structure of composites, the uniform distribution of the CCTO particles in the matrix plays a key role on the dielectric enhancement. Due to the influence of the CCTO on the microstructure of the polymer matrix, the composites exhibit a weaker temperature dependence of the dielectric constant than the polymer matrix. Based on the results, it is also found that the loss of the composites at low temperatures, including room temperature, is determined by the real dielectric relaxation processes including the relaxation process induced by the mixing.- Published
- 2016
- Full Text
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6. Relative dominance of HLA-B*07 restricted CD8+ T-lymphocyte immune responses to human cytomegalovirus pp65 in persons sharing HLA-A*02 and HLA-B*07 alleles.
- Author
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Lacey SF, Villacres MC, La Rosa C, Wang Z, Longmate J, Martinez J, Brewer JC, Mekhoubad S, Maas R, Leedom JM, Forman SJ, Zaia JA, and Diamond DJ
- Subjects
- Alleles, Cytokines metabolism, Cytomegalovirus Infections genetics, Cytomegalovirus Infections immunology, HLA-B7 Antigen, Humans, Immunodominant Epitopes immunology, Interleukin-2 metabolism, Leukocytes, Mononuclear immunology, Peptide Fragments pharmacology, Stem Cell Transplantation, CD8-Positive T-Lymphocytes immunology, HLA-A Antigens genetics, HLA-B Antigens genetics, Phosphoproteins immunology, Viral Matrix Proteins immunology
- Abstract
CD8(+) T-cell responses to three human cytomegalovirus (CMV) pp65 epitopes were studied in panels of healthy seropositive HLA-A*02/HLA-B*07 individuals, and HLA-A*02 donors mismatched for HLA-B*07. The majority of the latter had significant responses to a HLA-A*02-restricted epitope within the CMV pp65 antigen. By contrast, the strongest responses to CMV in the first group were to HLA-B*07-restricted epitopes. Similar immunodominance of HLA-B*07 over HLA-A*02 was found in two immunocompromised HIV-infected HLA-A*02/HLA-B*07 patients, and in the reconstituting immune system of three stem cell transplant recipients. In vitro stimulation of peripheral blood mononuclear cells (PBMC) from two immunocompetent HLA-A*02/HLA-B*07 individuals indicated that cytotoxic T lymphocyte (CTL) precursors specific for both HLA-A*02 and HLA-B*07 restricted epitopes were present and could be expanded by stimulation with the cognate peptides. However, if stimulation was performed by antigen presenting cells infected with recombinant vaccinia expressing full-length native pp65, only HLA-B*07 epitope-specific cells were seen. In one patient the HLA-B*07 dominance was partially broken by using recombinant vaccinia expressing ubiquitinated pp65, suggesting that enhanced protein processing can reveal weaker immune responses. Our results indicate that CMV-specific cellular immune responses restricted by HLA-B*07 dominate those restricted by HLA-A*02 in both immunocompetent and immunocompromised individuals. This may have significant consequences for the design of epitope-specific vaccines.
- Published
- 2003
- Full Text
- View/download PDF
7. Preclinical development of an adjuvant-free peptide vaccine with activity against CMV pp65 in HLA transgenic mice.
- Author
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La Rosa C, Wang Z, Brewer JC, Lacey SF, Villacres MC, Sharan R, Krishnan R, Crooks M, Markel S, Maas R, and Diamond DJ
- Subjects
- Animals, Antigens, Viral metabolism, Cytomegalovirus immunology, Cytomegalovirus Vaccines chemistry, Cytomegalovirus Vaccines immunology, Drug Carriers administration & dosage, Drug Carriers pharmacology, Drug Evaluation, Preclinical, Epitopes administration & dosage, Epitopes immunology, Epitopes, T-Lymphocyte immunology, HLA Antigens genetics, HLA-A2 Antigen genetics, HLA-A2 Antigen immunology, Humans, Immunization, Malaria Vaccines chemical synthesis, Malaria Vaccines immunology, Mice, Mice, Transgenic, Oligodeoxyribonucleotides immunology, Peptides administration & dosage, Peptides chemical synthesis, Phosphoproteins chemical synthesis, Tetanus immunology, Viral Matrix Proteins chemical synthesis, Antigens, Viral immunology, Cytomegalovirus Vaccines administration & dosage, HLA Antigens immunology, Peptides immunology, Phosphoproteins immunology, Viral Matrix Proteins immunology
- Abstract
Epitope vaccines have shown promise for inducing cellular immune responses in animal models of infectious disease. In cases where cellular immunity was augmented, peptide vaccines composed of covalently linked minimal cytotoxic T-lymphocyte (CTL) and T-helper (T(H)) epitopes generally showed the most efficacy. To address a clinical vaccine strategy for cytomegalovirus (CMV) in the context of HCT (hematopoietic cell transplantation), we observed that linking the synthetically derived pan-DR epitope peptide (PADRE) or one of several tetanus T(H) epitopes to the immunodominant human leukocyte antigen (HLA) A*0201-restricted CTL epitope from CMV-pp65 to create a fusion peptide caused robust cytotoxic cellular immune responses in HLA A*0201/K(b) transgenic mice. Significantly, the fusion peptides are immunogenic when administered in saline solution by either subcutaneous or intranasal routes. CpG-containing single-stranded DNA (ss-oligodeoxynucleotide [ODN]) added to the fusion peptides dramatically up-regulated immune recognition by either route. Notably, target cells that either expressed full-length pp65 protein from vaccinia viruses or were sensitized with the CTL epitope encoded in the vaccine were recognized by splenic effectors from immunized animals. Visualization of murine peptide-specific CTL by flow cytometry was accomplished using an HLA A*0201 tetramer complexed with the pp65(495-503) CTL epitope. T(H)-CTL epitope fusion peptides in combination with CpG ss-ODN represent a new strategy for parenteral or mucosal delivery of vaccines in a safe and effective manner that has applicability for control or prophylaxis of infectious disease, especially in situations such as vaccination of donors or recipients of HCT, where highly inflammatory adjuvants are not desired.
- Published
- 2002
- Full Text
- View/download PDF
8. Routine inquiry of organ and tissue donation: the Oregon experience.
- Author
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Brewer JC, Hunt MJ, and Seely MS
- Subjects
- Consent Forms, Critical Care, Decision Making, Family psychology, Humans, Oregon, Health Policy, Informed Consent legislation & jurisprudence, Tissue Donors, Tissue and Organ Procurement organization & administration
- Abstract
This article introduces the critical care nurse to a successful statewide effort to promote organ and tissue donation. Because it was one of the first to implement routine inquiry, the state of Oregon's experience was watched closely by the nation. The need for, implementation, and effects of the first routine inquiry legislation in the United States are recounted and analyzed in this article.
- Published
- 1994
9. In vitro studies of HIV-1 expression in thymocytes from infants and children.
- Author
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Hays EF, Uittenbogaart CH, Brewer JC, Vollger LW, and Zack JA
- Subjects
- Cells, Cultured, Child, Child, Preschool, Culture Media, Serum-Free, Drug Synergism, Flow Cytometry, HIV Core Protein p24 analysis, HIV-1 drug effects, Humans, Infant, Infant, Newborn, T-Lymphocytes cytology, Thymus Gland cytology, Virus Replication drug effects, HIV-1 physiology, Interleukin-2 pharmacology, Interleukin-4 pharmacology, T-Lymphocytes microbiology, Thymus Gland microbiology
- Abstract
Objective: To determine whether thymocytes from infants and young children can be infected with and their maturation capability altered by HIV-1, and to examine the effects of interleukin (IL)-2 and IL-4 on this process., Design: Serum-free culture medium was used so that cytokine effects could be studied under defined conditions. The primary virus isolates HIV-1JR-CSF and HIV-1JR-FL were used because their effects should most closely resemble those of viruses which might be found in an infected child., Methods: Thymocytes from infants and young children were infected with virus and cultured in serum-free medium with the cytokines IL-2 and IL-4 alone or in combination. HIV-1 expression was measured after 12 days by p24 levels in culture supernatants. Thymocyte maturation was determined by changes in surface phenotype, as measured by flow cytometry., Results: HIV-1 expression by thymocytes, which increased with time of culture, occurred when thymocytes were cultured with each cytokine. p24 levels were slightly increased when cultured with IL-2, compared with IL-4. Virus expression was remarkably increased when the cytokines were combined in culture. This expression was synergistic rather than additive. The synergy, evident in mature, but not immature thymocytes, was demonstrated with both pharmacologic and physiologic concentrations of cytokines. T-cells from peripheral blood cultured under the same conditions demonstrated lower virus expression in the presence of cytokines and synergy was not shown. Cytokine-induced thymocyte maturation and thymocyte survival in vitro was unimpaired by infection with HIV-1., Conclusions: These findings indicate that the cytokines IL-2 and IL-4, which are normally present in the thymic environment, can synergize to promote HIV-1 expression by thymocytes infected in vitro. This occurs without impairing the maturation induced by these cytokines. Thus, the mature thymocyte may provide a continuous supply of virus-expressing T-cells to the peripheral blood and lymphoid tissues of the infected child.
- Published
- 1992
- Full Text
- View/download PDF
10. Prosthetic Dentistry.
- Author
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Brewer JC
- Published
- 1894
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