Biomedical Engineering and Bioengineering | Open Access Articles

Physiological And Transcriptional Memory In Guard Cells During Repetitive Dehydration Stress, Laetitia Virlouvet, Michael E. Fromm

Nebraska Center for Biotechnology: Faculty and Staff Publications

Arabidopsis plants subjected to a daily dehydration stress and watered recovery cycle display physiological and transcriptional stress memory. Previously stressed plants have stomatal apertures that remain partially closed during a watered recovery period, facilitating reduced transpiration during a subsequent dehydration stress. Guard cells (GCs) display transcriptional memory that is similar to that in leaf tissues for some genes, but display GC-specific transcriptional memory for other genes. The rate-limiting abscisic acid (ABA) biosynthetic genes NINE-CIS-EPOXYCAROTENOID DIOXYGENASE 3 (NCED3) and ALDEHYDE OXIDASE 3 (AAO3) are expressed at much higher levels in GCs, particularly during the watered recovery interval, relative to their low …

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The Pseudomonas Syringae Type Iii Effector Hopd1 Suppresses Effector-Triggered Immunity, Localizes To The Endoplasmic Reticulum, And Targets The Arabidopsis Transcription Factor Ntl9, Anna Block, Tania Y. Toruno, Christian G. Elowsky, Chi Zhang, Jens Steinbrenner, Jim Beynon, James R. Alfano

Nebraska Center for Biotechnology: Faculty and Staff Publications

Pseudomonas syringae type III effectors are known to suppress plant immunity to promote bacterial virulence. However, the activities and targets of these effectors are not well understood. We used genetic, molecular, and cell biology methods to characterize the activities, localization, and target of the HopD1 type III effector in Arabidopsis. HopD1 contributes to P. syringae virulence in Arabidopsis and reduces effector-triggered immunity (ETI) responses but not pathogen-associated molecular pattern-triggered immunity (PTI) responses. Plants expressing HopD1 supported increased growth of ETI-inducing P. syringae strains compared with wild-type Arabidopsis. We show that HopD1 interacts with the membrane-tethered Arabidopsis transcription factor NTL9 and …

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Near-Infrared Surface-Enhanced Fluorescence Using Silver Nanoparticles In Solution, Michael D. Furtaw

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Fluorescence spectroscopy is a widely used detection technology in many research and clinical assays. Further improvement to assay sensitivity may enable earlier diagnosis of disease, novel biomarker discovery, and ultimately, improved outcomes of clinical care along with reduction in costs. Near-infrared, surface-enhanced fluorescence (NIR-SEF) is a promising approach to improve assay sensitivity via simultaneous increase in signal with a reduction in background. This dissertation describes research conducted with the overall goal to determine the extent to which fluorescence in solution may be enhanced by altering specific variables involved in the formation of plasmonactive nanostructures of dye-labeled protein and silver nanoparticles …

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A Morphological Analysis Of A Hybrid Swarm Of Native Ulmus Rubra And Introduced U. Pumila (Ulmaceae) In Southeastern Nebraska, Christian Elowsky, Ingrid E. Jordon-Thaden, Robert B. Kaul

Nebraska Center for Biotechnology: Faculty and Staff Publications

The parental species and hybrid swarm of native Ulmus rubra Muhl. and the introduced, naturalized and weedy U. pumila L. were investigated in a 65-km transect in Lancaster, Saunders, and Butler counties in Nebraska. Thirty-two trees of U. rubra, 32 of U. pumila, and 50 of the hybrid swarm were sampled for leaves and buds and subsampled for flowers and fruits. Leaves were measured for petiole length, blade length, width, primary and secondary teeth per cm, number of secondary teeth per primary tooth, and texture. Buds were scored for color and distribution of trichomes. Flowers were sampled for stamen counts …

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Bile-Acid-Mediated Decrease In Endoplasmic Reticulum Stress: A Potential Contributor To The Metabolic Benefits Of Ileal Interposition Surgery In Ucd-T2dm Rats, Bethany P. Cummings, Ahmed Bettaieb, James L. Graham, Jaehyoung Kim, Fangrui Ma, Noreene Shibata, Kimber L. Stanhope, Cecilia Giulivi, Frederik Hansen, Jacob Jelsing, Niels Vrang, Mark Kowala, Michael L. Chouinard, Fawaz G. Haj, Peter J. Havel

Nebraska Center for Biotechnology: Faculty and Staff Publications

Post-operative increases in circulating bile acids have been suggested to contribute to the metabolic benefits of bariatric surgery; however, their mechanistic contributions remain undefined. We have previously reported that ileal interposition (IT) surgery delays the onset of type 2 diabetes in UCD-T2DM rats and increases circulating bile acids, independently of effects on energy intake or body weight. Therefore, we investigated potential mechanisms by which post-operative increases in circulating bile acids improve glucose homeostasis after IT surgery. IT, sham or no surgery was performed on 2-month-old weight-matched male UCD-T2DM rats. Animals underwent an oral fat tolerance test (OFTT) and serial oral …

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Mononuclear Phagocyte Intercellular Crosstalk Facilitates Transmission Of Cell-Targeted Nanoformulated Antiretroviral Drugs To Human Brain Endothelial Cells, Georgette D. Kanmogne, Sangya Singh, Upal Roy, Xinming Liu, Joellyn Mcmillan, Santhi Gorantla, Shantanu Balkundi, Nathan Smith, Yazen Alnouti, Nagsen Gautam, You Zhou, Larisa Poluektova, Alexander Kabanov, Tatiana Bronich, Howard Gendelman

Nebraska Center for Biotechnology: Faculty and Staff Publications

Despite the successes of antiretroviral therapy (ART), HIV-associated neurocognitive disorders remain prevalent in infected people. This is due, in part, to incomplete ART penetration across the blood–brain barrier (BBB) and lymph nodes and to the establishment of viral sanctuaries within the central nervous system. In efforts to improve ART delivery, our laboratories developed a macrophage-carriage system for nanoformulated crystalline ART (nanoART) (atazanavir, ritonavir, indinavir, and efavirenz). We demonstrate that nanoART transfer from mononuclear phagocytes (MP) to human brain microvascular endothelial cells (HBMEC) can be realized through cell-to-cell contacts, which can facilitate drug passage across the BBB. Coculturing of donor MP …

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Bacterial Killing By Dry Metallic Copper Surfaces, Christophe Espírito Santo, Ee Wen Lam, Christian Elowsky, Davide Quaranta, Dylan W. Domaille, Christopher J. Chang, Gregor Grass

Nebraska Center for Biotechnology: Faculty and Staff Publications

Metallic copper surfaces rapidly and efficiently kill bacteria. Cells exposed to copper surfaces accumulated large amounts of copper ions, and this copper uptake was faster from dry copper than from moist copper. Cells suffered extensive membrane damage within minutes of exposure to dry copper. Further, cells removed from copper showed loss of cell integrity. Acute contact with metallic copper surfaces did not result in increased mutation rates or DNA lesions. These findings are important first steps for revealing the molecular sensitive targets in cells lethally challenged by exposure to copper surfaces and provide a scientific explanation for the use of …

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Fus Transgenic Rats Develop The Phenotypes Of Amyotrophic Lateral Sclerosis And Frontotemporal Lobar Degeneration, Cao Huang, Hongxia Zhou, Jianbin Tong, Han Chen, Yong-Jian Liu, Dian Wang, Xiaotao Wei, Xugang Xia

Nebraska Center for Biotechnology: Faculty and Staff Publications

Fused in Sarcoma (FUS) proteinopathy is a feature of frontotemporal lobar dementia (FTLD), and mutation of the fus gene segregates with FTLD and amyotrophic lateral sclerosis (ALS). To study the consequences of mutation in the fus gene, we created transgenic rats expressing the human fus gene with or without mutation. Overexpression of a mutant (R521C substitution), but not normal, human FUS induced progressive paralysis resembling ALS. Mutant FUS transgenic rats developed progressive paralysis secondary to degeneration of motor axons and displayed a substantial loss of neurons in the cortex and hippocampus. This neuronal loss was accompanied by ubiquitin aggregation and …

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Comparative Manufacture And Cell-Based Delivery Of Antiretroviral Nanoformulations, Shantanu Balkundi, Ari S. Nowacek, Ram S. Veerubhotla, Han Chen, Andrea Martinez-Skinner, Upal Roy, R. Lee Mosley, Georgette Kanmogne, Xinming Liu, Alexander V. Kabanov, Tatiana Bronich, Joellyn Mcmillan, Howard E. Gendelman

Nebraska Center for Biotechnology: Faculty and Staff Publications

Nanoformulations of crystalline indinavir, ritonavir, atazanavir, and efavirenz were manufactured by wet milling, homogenization or sonication with a variety of excipients. The chemical, biological, immune, virological, and toxicological properties of these formulations were compared using an established monocyte-derived macrophage scoring indicator system. Measurements of drug uptake, retention, release, and antiretroviral activity demonstrated differences amongst preparation methods. Interestingly, for drug cell targeting and antiretroviral responses the most significant difference among the particles was the drug itself. We posit that the choice of drug and formulation composition may ultimately affect clinical utility.

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Transgenic Rat Model Of Neurodegeneration Caused By Mutation In The Tdp Gene, Hongxia Zhou, Cao Huang, Han Chen, Dian Wang, Carlisle P. Landel, Pedro Yuxing Xia, Robert Bowser, Yong-Jian Liu, Xu Gang Xia

Nebraska Center for Biotechnology: Faculty and Staff Publications

TDP-43 proteinopathies have been observed in a wide range of neurodegenerative diseases. Mutations in the gene encoding TDP-43 (i.e., TDP) have been identified in amyotrophic lateral sclerosis (ALS) and in frontotemporal lobe degeneration associated with motor neuron disease. To study the consequences of TDP mutation in an intact system, we created transgenic rats expressing normal human TDP or a mutant form of human TDP with a M337V substitution. Overexpression of mutant, but not normal, TDP caused widespread neurodegeneration that predominantly affected the motor system. TDP mutation reproduced ALS phenotypes in transgenic rats, as seen by progressive degeneration of motor neurons …

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The Highly Similar Arabidopsis Homologs Of Trithorax Atx1 And Atx2 Encode Proteins With Divergent Biochemical Functions, Abdelaty Saleh, Raul Alvarez-Venegas, Mehtap Yilmaz, Oahn-Le, Guichuan Hou, Monther Sadder, Ayed Al-Abdallat, Yuannan Xia, Guoqinq Lu, Istvan Ladunga, Zoya Avramova

Nebraska Center for Biotechnology: Faculty and Staff Publications

Gene duplication followed by functional specialization is a potent force in the evolution of biological diversity. A comparative study of two highly conserved duplicated genes, ARABIDOPSIS TRITHORAX-LIKE PROTEIN1 (ATX1) and ATX2, revealed features of both partial redundancy and of functional divergence. Although structurally similar, their regulatory sequences have diverged, resulting in distinct temporal and spatial patterns of expression of the ATX1 and ATX2 genes. We found that ATX2 methylates only a limited fraction of nucleosomes and that ATX1 and ATX2 influence the expression of largely nonoverlapping gene sets. Even when coregulating shared targets, ATX1 and ATX2 may employ different …

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Construction Of A Derivative Of Agrobacterium Tumefaciens C58 That Does Not Mutate To Tetracycline Resistance, Zhao-Qing Luo, Thomas E. Clemente, Stephen K. Farrand

Nebraska Center for Biotechnology: Faculty and Staff Publications

Agrobacterium tumefaciens C58 mutates to tetracycline resistance at high frequency, complicating the use of many broad-host-range cloning and binary vectors that code for resistance to this antibiotic as the selection marker. Such mutations are associated with a resistant gene unit, tet_C58, that is present in the genome of this strain. By deleting the tet_C58 locus, we constructed NTL4, a derivative of C58 that no longer mutates to tetracycline resistance. The deletion had no detectable effect on genetic or physiological traits of NTL4 or on the ability of this strain to transform plants.

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Biodiesel Fuel From Animal Fat. Ancillary Studies On Transesterification Of Beef Tallow, Fangrui Ma, L. Davis Clements, Milford Hanna

Nebraska Center for Biotechnology: Faculty and Staff Publications

Transesterification of beef tallow was investigated. The solubility of ethanol in beef tallow was much higher than that of methanol. At 100 °C the solubility of methanol was 19% (w/w). The solubility of ethanol in beef tallow reached 100% (w/w) at about 68 °C. For the distribution of methanol between beef tallow methyl esters (BTME) and glycerol, the percentage of total methanol in the glycerol phase was higher than that in the fatty acid methyl ester (FAME) phase in a simulated system at room temperature. At 65-80 °C, however, the percentage of total methanol in FAME (60% (w/w)) was higher …

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Full-Text Articles in Biomedical Engineering and Bioengineering

Physiological And Transcriptional Memory In Guard Cells During Repetitive Dehydration Stress, Laetitia Virlouvet, Michael E. Fromm

Nebraska Center for Biotechnology: Faculty and Staff Publications

The Pseudomonas Syringae Type Iii Effector Hopd1 Suppresses Effector-Triggered Immunity, Localizes To The Endoplasmic Reticulum, And Targets The Arabidopsis Transcription Factor Ntl9, Anna Block, Tania Y. Toruno, Christian G. Elowsky, Chi Zhang, Jens Steinbrenner, Jim Beynon, James R. Alfano

Nebraska Center for Biotechnology: Faculty and Staff Publications

Near-Infrared Surface-Enhanced Fluorescence Using Silver Nanoparticles In Solution, Michael D. Furtaw

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

A Morphological Analysis Of A Hybrid Swarm Of Native Ulmus Rubra And Introduced U. Pumila (Ulmaceae) In Southeastern Nebraska, Christian Elowsky, Ingrid E. Jordon-Thaden, Robert B. Kaul

Nebraska Center for Biotechnology: Faculty and Staff Publications

Nebraska Center for Biotechnology: Faculty and Staff Publications

Nebraska Center for Biotechnology: Faculty and Staff Publications

Bacterial Killing By Dry Metallic Copper Surfaces, Christophe Espírito Santo, Ee Wen Lam, Christian Elowsky, Davide Quaranta, Dylan W. Domaille, Christopher J. Chang, Gregor Grass

Nebraska Center for Biotechnology: Faculty and Staff Publications

Fus Transgenic Rats Develop The Phenotypes Of Amyotrophic Lateral Sclerosis And Frontotemporal Lobar Degeneration, Cao Huang, Hongxia Zhou, Jianbin Tong, Han Chen, Yong-Jian Liu, Dian Wang, Xiaotao Wei, Xugang Xia

Nebraska Center for Biotechnology: Faculty and Staff Publications

Nebraska Center for Biotechnology: Faculty and Staff Publications

Transgenic Rat Model Of Neurodegeneration Caused By Mutation In The Tdp Gene, Hongxia Zhou, Cao Huang, Han Chen, Dian Wang, Carlisle P. Landel, Pedro Yuxing Xia, Robert Bowser, Yong-Jian Liu, Xu Gang Xia

Nebraska Center for Biotechnology: Faculty and Staff Publications

The Highly Similar Arabidopsis Homologs Of Trithorax Atx1 And Atx2 Encode Proteins With Divergent Biochemical Functions, Abdelaty Saleh, Raul Alvarez-Venegas, Mehtap Yilmaz, Oahn-Le, Guichuan Hou, Monther Sadder, Ayed Al-Abdallat, Yuannan Xia, Guoqinq Lu, Istvan Ladunga, Zoya Avramova

Nebraska Center for Biotechnology: Faculty and Staff Publications

Construction Of A Derivative Of Agrobacterium Tumefaciens C58 That Does Not Mutate To Tetracycline Resistance, Zhao-Qing Luo, Thomas E. Clemente, Stephen K. Farrand

Nebraska Center for Biotechnology: Faculty and Staff Publications

Biodiesel Fuel From Animal Fat. Ancillary Studies On Transesterification Of Beef Tallow, Fangrui Ma, L. Davis Clements, Milford Hanna

Nebraska Center for Biotechnology: Faculty and Staff Publications