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Exposure To Asphalt Fumes Activates Activator Protein-1 Through The Phosphatidylinositol 3-Kinase/Akt Signaling Pathway In Mouse Epidermal Cells, Cuiling Ma, Jin Wang, Jia Luo

Faculty & Staff Scholarship

No abstract provided.

Selective Expression Of Beta Tubulin Isotypes In Gerbil Vestibular Sensory Epithelia And Neurons, Brian Perry, Heather Jensen Smith, Richard F. Ludueña, Richard Hallworth

Journal Articles: Eppley Institute

The seven mammalian isotypes of beta tubulin are strikingly similar in amino acid sequence. The differences in isotypic sequence, although small, are nonetheless conserved in evolution, which suggests that they may confer distinct functional roles. If so, such roles should be reflected in the selective expression of isotypes by cell type, or even in the sorting of isotypes to within-cell pools. Hair cells of the vestibular sensory epithelia each possess a kinocilium, a microtubule-based organelle that could represent a distinct microtubule compartment, separate from the extensive microtubule network in the soma. The afferent neurons that innervate the vestibular sensory epithelia …

Cell Type-Specific Reduction Of Beta Tubulin Isotypes Synthesized In The Developing Gerbil Organ Of Corti, Heather Jensen Smith, Jonquille Eley, Peter S. Steyger, Richard F. Ludueña, Richard Hallworth

Journal Articles: Eppley Institute

There are seven isotypic forms of the microtubule protein beta tubulin in mammals, but not all isotypes are synthesized in every cell type. In the adult organ of Corti, each of the five major cell types synthesizes a different subset of isotypes. Inner hair cells synthesize only betaI and betaII tubulin, while outer hair cells make betaI and betaIV tubulin. Only betaII and betaIV tubulin are found in inner and outer pillar cells, while betaI, betaII, and betaIV tubulin are present in Deiters cells, and betaI, betaII and betaIII tubulin are found in organ of Corti dendrites. During post-natal organ …

G03-1527 Annual Forages For The Nebraska Panhandle, Burt A. Weichenthal, David D. Baltensperger, K. P. Vogel, S. D. Masterson, J.M. Blumenthal, J.M. Krall

University of Nebraska-Lincoln Extension: Historical Materials

Annual forages have value as pasture, green chop, silage, and hay. With adequate soil moisture, these forages grow very rapidly during their appropriate growing seasons. Advantages and disadvantages of various annual forages, results of dryland and irrigated forage trials, tips for achieving quality forage, and issues related to animal health and feeding forages are discussed in this NebGuide.

G03-1513 Understanding Fungal (Mold) Toxins (Mycotoxins), Michael P. Carlson, Steveb M. Ensley

University of Nebraska-Lincoln Extension: Historical Materials

Mycotoxins are chemicals produced by fungi (molds) under certain conditions. They are not essential for fungal growth or reproduction, and are toxic to animals or humans.

This NebGuide briefly discusses mycotoxins commonly encountered in grains and feeds used in Nebraska and the mycotoxicoses they cause. Mycotoxin sources and clinical signs, lesions, diagnostic aids and treatment for each mycotoxicosis are listed.

Nf03-571 Aspergillus Flavus And Aflatoxins In Corn, Jim Stack, Michael Carlson

University of Nebraska-Lincoln Extension: Historical Materials

The severe weather conditions of the 2002 growing season resulted in an increase in the incidence and severity of aflatoxin contamination of both food grade and feed grade corn in Nebraska.

The mycotoxin called aflatoxin is produced by the grain mold Aspergillus flavus. Not all isolates of A. flavus produced aflatoxin and isolates that are capable of producing aflatoxin do not always synthesize the toxin. Many factors including environmental conditions and host suscepbitility, determine the incidence and severity of grain mold and subsequent mycotoxin contamination.

This NebFact discusses the cause and occurrence of aflatoxin in corn; the effects it has …

Nf03-570 Fumonisins In Corn, Jim Stack, Michael Carlson

University of Nebraska-Lincoln Extension: Historical Materials

During the past two years, millers have rejected some Nebraska food grade corn because it was contaminated with the mycotoxin fumonisin. Most of the contaminated samples and the highest levels of contamination were detected in corn from counties in the eastern half of Nebraska.

Fumonisins are mycotoxins produced by the grain molds Fusarium verticillioides and Fusarium proliferatum. These fungi are commonly found in corn throughout the United States.

This NebFact discusses the cause and occurrence of fumonisin in corn; the effects it has on plants, animals and humans; and management options to minimize fumonisin contamination.

G03-1501 Prudent Use Of Antibiotics In Companion Animals, Katherine Irwin, David R. Smith, Grasso M. Ebako, Steve Ensley, Dicky D. Griffin, Arden Wohlers

University of Nebraska-Lincoln Extension: Historical Materials

This NebGuide explains why antibiotics must be used with care and how to prudently use antibiotics to treat companion animals.

Antibiotics are used to improve animal health and performance. You, as the animal owner or caregiver, make important decisions about how antibiotics are finally used in companion animals. Antibiotics should be used prudently to ensure they are effective and will continue to benefit man and animals in the future. Are you prepared to make the best decisions about using antibiotics in animals?

The Mare Reproductive Loss Syndrome And The Eastern Tent Caterpillar: A Toxicokinetic/Statistical Analysis With Clinical, Epidemiologic, And Mechanistic Implications, Manu Sebastian, Marie G. Gantz, Thomas Tobin, J. Daniel Harkins, Jeffrey M. Bosken, Charlie Hughes, Lenn R. Harrison, William V. Bernard, Dana L. Richter, Terrence D. Fitzgerald

Maxwell H. Gluck Equine Research Center Faculty Publications

During 2001, central Kentucky experienced acute transient epidemics of early and late fetal losses, pericarditis, and unilateral endophthalmitis, collectively referred to as mare reproductive loss syndrome (MRLS). A toxicokinetic/statistical analysis of experimental and field MRLS data was conducted using accelerated failure time (AFT) analysis of abortions following administration of Eastern tent caterpillars (ETCs; 100 or 50 g/day or 100 g of irradiated caterpillars/day) to late-term pregnant mares. In addition, 2001 late-term fetal loss field data were used in the analysis. Experimental data were fitted by AFT analysis at a high (P < .0001) significance. Times to first abortion (“lag time”) and abortion rates were dose dependent. Lag times decreased and abortion rates increased exponentially with dose. Calculated dose × response data curves allow interpretation of abortion data in terms of “intubated ETC equivalents.” Analysis suggested that field exposure to ETCs in 2001 in central Kentucky commenced on approximately April 27, was initially equivalent to approximately 5 g of intubated ETCs/day, and increased to approximately 30 g/day at the outbreak peak. This analysis accounts for many aspects of the epidemiology, clinical presentations, and manifestations of MRLS. It allows quantitative interpretation of experimental and field MRLS data and has implications for the basic mechanisms underlying MRLS. The results support suggestions that MRLS is caused by exposure to or ingestion of ETCs. The results also show that high levels of ETC exposure produce intense, focused outbreaks of MRLS, closely linked in time and place to dispersing ETCs, as occurred in central Kentucky in 2001. With less intense exposure, lag time is longer and abortions tend to spread out over time and may occur out of phase with ETC exposure, obscuring both diagnosis of this syndrome and the role of the caterpillars.

Manganese Distribution Across The Blood-Brain Barrier. I. Evidence For Carrier-Mediated Influx Of Managanese Citrate As Well As Manganese And Manganese Transferrin, Janelle S. Crossgrove, David D. Allen, Bonny L. Bukaveckas, Susan S. Rhineheimer, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

Manganese (Mn) is an essential element and a neurotoxicant. Regulation of Mn movement across the blood–brain barrier (BBB) contributes to whether the brain Mn concentration is functional or toxic. In plasma, Mn associates with water, small molecular weight ligands and proteins. Mn speciation may influence the kinetics of its movement through the BBB. In the present work, the brain influx rates of ⁵⁴Mn²⁺, ⁵⁴Mn citrate and ⁵⁴Mn transferrin (⁵⁴Mn Tf) were determined using the in situ brain perfusion technique. The influx rates were compared to their predicted diffusion rates, which were determined from …

The Permeability Of The Endoplasmic Reticulum Is Dynamically Coupled To Protein Synthesis, Anirban Roy, William F. Wonderlin

Faculty & Staff Scholarship

No abstract provided.

Nucleotide Excision Repair- And Polymerase Eta-Mediated Error-Prone Removal Of Mitomycin C Interstrand Cross-Links, H. Zheng, X. Wang, A. J. Warren, R. J. Legerski, Rodney S. Nairn, Joshua W. Hamilton, Lei Li

Dartmouth Scholarship

Interstrand cross-links (ICLs) make up a unique class of DNA lesions in which both strands of the double helix are covalently joined, precluding strand opening during replication and transcription. The repair of DNA ICLs has become a focus of study since ICLs are recognized as the main cytotoxic lesion inflicted by an array of alkylating compounds used in cancer treatment. As is the case for double-strand breaks, a damage-free homologous copy is essential for the removal of ICLs in an error-free manner. However, recombination-independent mechanisms may exist to remove ICLs in an error-prone fashion. We have developed an in vivo …

Activation Of Jnk By Vanadate Induces A Fas-Associated Death Domain (Fadd)-Dependent Death Of Cerebellar Granule Progenitors In Vitro, Jia Luo, Yanbo Sun, Hong Lin, Yong Qian, Zheng Li, Stephen S. Leonard, Chuanshu Huang, Xianglin Shi

Faculty & Staff Scholarship

No abstract provided.

Hydrogen Peroxide Formation And Actin Filament Reorganization By Cdc42 Are Essential For Ethanol-Induced In Vitro Angiogenesis, Yong Qian, Jia Luo, Stephen S. Leonard, Gabriel K. Harris, Lyndell Millecchia, Daniel C. Flynn, Xianglin Shi

Faculty & Staff Scholarship

No abstract provided.

A Genetic Lesion That Arrests Plasma Cell Homing To The Bone Marrow, Loren D. Erickson, Ling-Li Lin, Biyan Duan, Laurence Morel, Randolph J. Noelle

Dartmouth Scholarship

The coordinated regulation of chemokine responsiveness plays a critical role in the development of humoral immunity. After antigen challenge and B cell activation, the emerging plasma cells (PCs) undergo CXCL12-induced chemotaxis to the bone marrow, where they produce Ab and persist. Here we show that PCs, but not B cells or T cells from lupus-prone NZM mice, are deficient in CXCL12-induced migration. PC unresponsiveness to CXCL12 results in a marked accumulation of PCs in the spleen of mice, and a concordant decrease in bone marrow PCs. Unlike normal mice, in NZM mice, a majority of the splenic PCs are long-lived. …

Polyadenylation Regulates The Stability Of Trypanosoma Brucei Mitochondrial Rnas, Christopher M. Ryan, Kevin T. Militello, Laurie K. Read

Biology

Polyadenylation of RNAs plays a critical role in modulating rates of RNA turnover and ultimately in controlling gene expression in all systems examined to date. In mitochondria, the precise mechanisms by which RNAs are degraded, including the role of polyadenylation, are not well understood. Our previous in organello pulse-chase experiments suggest that poly(A) tails stimulate degradation of mRNAs in the mitochondria of the protozoan parasite Trypanosoma brucei (Militello, K. T., and Read, L. K. (2000) Mol. Cell. Biol. 21, 731-742). In this report, we developed an in vitro assay to directly examine the effects of specific 3′-sequences on RNA degradation. …

The Sh4-Unique-Sh3-Sh2 Domains Dictate Specificity In Signaling That Differentiate C-Yes From C-Src, J. M. Summy

Faculty & Staff Scholarship

No abstract provided.

The Least Of The Sentient Beings' And The Question Of Reduction, Refinement, And Replacement, Joseph Vining

Other Publications

The subject I was asked to think about with you today is raised by a very large change in the focus of biomedical research. In raw percentage terms, the animals involved in experimentation are now overwhelmingly rats and mice, and, perhaps because they are rats and mice, they are used in large numbers, numbers in thousands and tens of thousands at some institutions. Legal, ethical, and practical accommodation to this fact on the ground presents a host of questions. There are questions of the cost of care. There are questions of the training of veterinarians, principal investigators, and laboratory personnel. …

Myosin Heavy Chain And Physiological Adaptation Of The Rat Diaphragm In Elastase-Induced Emphysema., Dong Kwan Kim, Jianliang Zhu, Benjamin W Kozyak, James M Burkman, Neal A Rubinstein, Edward B Lankford, Hansell H Stedman, Taitan Nguyen, Sanford Levine, Joseph B Shrager

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Several physiological adaptations occur in the respiratory muscles in rodent models of elastase-induced emphysema. Although the contractile properties of the diaphragm are altered in a way that suggests expression of slower isoforms of myosin heavy chain (MHC), it has been difficult to demonstrate a shift in MHCs in an animal model that corresponds to the shift toward slower MHCs seen in human emphysema. METHODS: We sought to identify MHC and corresponding physiological changes in the diaphragms of rats with elastase-induced emphysema. Nine rats with emphysema and 11 control rats were studied 10 months after instillation with elastase. MHC isoform …

Separation Custody, And Estate Planning Issues Relating To Companion Animals, Rebecca J. Huss

University of Colorado Law Review

No abstract provided.

Signaling And Regulation Of G Protein-Coupled Receptors In Airway Smooth Muscle., Charlotte K Billington, Raymond B Penn

Department of Medicine Faculty Papers

Signaling through G protein-coupled receptors (GPCRs) mediates numerous airway smooth muscle (ASM) functions including contraction, growth, and "synthetic" functions that orchestrate airway inflammation and promote remodeling of airway architecture. In this review we provide a comprehensive overview of the GPCRs that have been identified in ASM cells, and discuss the extent to which signaling via these GPCRs has been characterized and linked to distinct ASM functions. In addition, we examine the role of GPCR signaling and its regulation in asthma and asthma treatment, and suggest an integrative model whereby an imbalance of GPCR-derived signals in ASM cells contributes to the …

Rac-1 And Iqgap Are Potential Regulators Of E-Cadherin-Catenin Interactions During Murine Preimplantation Development., David R Natale, Andrew J Watson

Obstetrics & Gynaecology Publications

Adherens junction formation is fundamental for compaction and trophectoderm differentiation during mammalian preimplantation development. We recently isolated an IQGAP-2 cDNA from a differential display-polymerase chain reaction screen of bovine preimplantation developmental stages. IQGAP-1 and -2 proteins mediate E-cadherin-based cell-to-cell adhesion through interactions with beta-catenin and the Rho GTPases, rac1 and cdc42. Our study demonstrates IQGAP-1,-2, rac-1 and cdc42 mRNAs are present throughout murine preimplantation development. IQGAP-1 and rac-1 protein distribution changes from predominantly plasma membrane associated to predominantly cytoplasmic as the embryo progresses through cleavage divisions and compaction to the blastocyst stage.

The Cd154/Cd40 Interaction Required For Retrovirus-Induced Murine Immunodeficiency Syndrome Is Not Mediated By Upregulation Of The Cd80/Cd86 Costimulatory Molecules, Kathy A. Green, W. James Cook, Arlene H. Sharpe, William R. Green

Dartmouth Scholarship

C57BL/6 (B6) mice infected with LP-BM5 retroviruses develop disease, including an immunodeficiency similar to AIDS. This disease, murine AIDS (MAIDS), is inhibited by in vivo anti-CD154 monoclonal antibody treatment. The similar levels of insusceptibility of CD40^−/− and CD154^−/− B6 mice indicate that CD154/CD40 molecular interactions are required for MAIDS. CD4⁺ T and B cells, respectively, provide the CD154 and CD40 expression needed for MAIDS induction. Here, the required CD154/CD40 interaction is shown to be independent of CD80 and CD86 expression: CD80/CD86^−/− B6 mice develop MAIDS after LP-BM5 infection.

Gag Proteins Of The Two Drosophila Telomeric Retrotransposons Are Targeted To Chromosome Ends, Svetlana Rashkova, Sarah E. Karam, Rebecca Kellum, Mary-Lou Pardue

Biology Faculty Publications

Drosophila telomeres are formed by two non-LTR retrotransposons, HeT-A and TART, which transpose only to chromosome ends. Successive transpositions of these telomeric elements yield arrays that are functionally equivalent to the arrays generated by telomerase in other organisms. In contrast, other Drosophila non-LTR retrotransposons transpose widely through gene-rich regions, but not to ends. The two telomeric elements encode very similar Gag proteins, suggesting that Gag may be involved in their unique targeting to chromosome ends. To test the intrinsic potential of these Gag proteins for targeting, we tagged the coding sequences with sequence of GFP and expressed the constructs …

A Reduced Model Clarifies The Role Of Feedback Loops And Time Delays In The Drosophila Circadian Oscillator, Paul Smolen, Douglas A. Baxter, John H. Byrne

Faculty, Staff and Student Publications

Although several detailed models of molecular processes essential for circadian oscillations have been developed, their complexity makes intuitive understanding of the oscillation mechanism difficult. The goal of the present study was to reduce a previously developed, detailed model to a minimal representation of the transcriptional regulation essential for circadian rhythmicity in Drosophila. The reduced model contains only two differential equations, each with time delays. A negative feedback loop is included, in which PER protein represses per transcription by binding the dCLOCK transcription factor. A positive feedback loop is also included, in which dCLOCK indirectly enhances its own formation. The model …

Spotted Substrates For Focal Presentation Of Proteins To Cells, Terrance Kummer, Hiroshi Nishimune, Rachel Wong, Joshua Sanes

Open Access Publications

Neurites and other cell processes encounter localized deposits of signaling factors as they grow. The difficulty in generating patterned artificial substrates has hindered the analysis of these instructive factors in vitro. Here we report a simple method for presenting cultured cells with small spots of protein on an otherwise uniform substrate. We use a biolistic device called a gene gun to deposit 0.1-5 microm fluorescent dots of pure protein on or beneath a growth-promoting substrate. Using this technique, we demonstrate local presynaptic differentiation of motoneurons in response to dots of a polycation. We also show that biotin-avidin and antibody-antigen interactions …

Mad2 And Bubr1 Function In A Single Checkpoint Pathway That Responds To A Loss Of Tension, Katie Shannon, Julie C. Canman, Edward D. Salmon

Biological Sciences Faculty Research & Creative Works

The spindle checkpoint monitors microtubule attachment and tension at kinetochores to ensure proper chromosome segregation. Previously, PtK1 cells in hypothermic conditions (23°C) were shown to have a pronounced mitotic delay, despite having normal numbers of kinetochore microtubules. At 23°C, we found that PtK1 cells remained in metaphase for an average of 101 min, compared with 21 min for cells at 37°C. The metaphase delay at 23°C was abrogated by injection of Mad2 inhibitors, showing that Mad2 and the spindle checkpoint were responsible for the prolonged metaphase. Live cell imaging showed that kinetochore Mad2 became undetectable soon after chromosome congression. Measurements …

Meiotic Cohesion Requires Accumulation Of Ord On Chromosomes Before Condensation, Eric M. Balicky, Matthew W. Endres, Cary Lai, Sharon E. Bickel

Dartmouth Scholarship

Cohesion between sister chromatids is a prerequisite for accurate chromosome segregation during mitosis and meiosis. To allow chromosome condensation during prophase, the connections that hold sister chromatids together must be maintained but still permit extensive chromatin compaction. In Drosophila, null mutations in the orientation disruptor (ord) gene lead to meiotic nondisjunction in males and females because cohesion is absent by the time that sister kinetochores make stable microtubule attachments. We provide evidence that ORD is concentrated within the extrachromosomal domains of the nuclei ofDrosophila primary spermatocytes during early G2, but accumulates on the meiotic chromosomes by …

The Gamma-Subunit Of The Na-K-Atpase As A Potential Regulator Of Apical And Basolateral Na+-Pump Isozymes During Development Of Bovine Pre-Attachment Embryos., L C Barcroft, S E Gill, A J Watson

Obstetrics & Gynaecology Publications

Expression and activity of the Na-K-ATPase within the basolateral membrane domains of the trophectoderm epithelium provide the driving force for accumulation of Na(+) and Cl(-) across the nascent epithelium, mediating fluid movement into the forming blastocoel. Within the trophectoderm of the bovine blastocyst, multiple isozymes of the Na-K-ATPase are expressed. Immunolocalization has demonstrated that the alpha1-isozyme localizes within the basolateral membrane, whereas the alpha 3-isozyme localizes to the apical cell margins. Gene-specific RT-PCR and wholemount indirect immunofluorescence confocal laser scanning microscopy were used to examine expression of the Na-K-ATPase gamma-subunit (a regulatory subunit of the Na-K-ATPase) throughout development of bovine …

Defective Cd19-Dependent Signaling In B-1a And B-1b B Lymphocyte Subpopulations., Goutam Sen, Hsin-Jung Wu, Gabriel Bikah, Chandrasekar Venkataraman, Darrell A Robertson, E Charles Snow, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Peritoneal and pleural cavities in mice and humans contain a unique population of B-lymphocytes called B-1 cells that are defective in B cell antigen receptor (BCR) signaling but have an increased propensity to produce autoantibodies. Several molecules such as Btk, Vav, and CD19 known to be important for BCR signaling have been shown to be critical for the development of B-1 cells from undefined precursors. Here we demonstrate that B-1 cell unresponsiveness to BCR cross-linking is in part due to defective signaling through CD19, a molecule known to modulate signaling thresholds in B cells. The defective CD19 signaling is manifested …