Life Sciences Commons^™

Microcirculation: Electrophysiological Basis For The Response Of Endothelial Cells To Inflammatory Mediators-Bradykinin, Kai Miao

Electronic Theses and Dissertations

Using conventional microelectrodes, I studied the electrical basis for determining the resting V$\sb{\rm m}$ in intact EC's from hamsters. The resting V$\sb{\rm m}$ were found to be $-$40 mV for aortic EC's and $-$43 mV for vena caval EC's. The contributions of ions to the resting V$\sb{\rm m}$ of aortic EC's were compared in terms of the transference number (t$\sb{\rm ion}$). To develop a technique for in situ monitoring changes in V$\sb{\rm m}$ of postcapillary venular EC's in the hamster mesentery, a voltage-sensitive fluorescent probe, bisoxonol, was used to load the cells and the fluorescence signals were analyzed under an …

A Thyroid Hormone-Regulated Gene In Xenopus Laevis Encodes A Type Iii Iodothyronine 5-Deiodinase., Donald L. St Germain, Robert Schwartzman, Walburga Croteau, Akira Kanamori, Zhou Wang, Donald D. Brown, Valerie Galton

Dartmouth Scholarship

The type III iodothyronine 5-deiodinase metabolizes thyroxine and 3,5,3'-triiodothyronine to inactive metabolites by catalyzing the removal of iodine from the inner ring. The enzyme is expressed in a tissue-specific pattern during particular stages of development in amphibia, birds, and mammals. Recently, a PCR-based subtractive hybridization technique has been used to isolate cDNAs prepared from Xenopus laevis tadpole tail mRNA that represent genes upregulated by thyroid hormone during metamorphosis. Sequence analysis of one of these cDNAs (XL-15) revealed regions of homology to the mRNA encoding the rat type I (outer ring) 5'-deiodinase, including a conserved UGA codon that encodes selenocysteine in …

Denervation Supersensitivity Of The Rat Vas Deferens: A Role For Protein Kinase C, Sonny T. Abraham

Electronic Theses and Dissertations

A role for protein kinase C (PKC) in the denervation-induced supersensitivity of the rat vas deferens was investigated. Chronic, surgical denervation of the rat vas deferens (up to 8 days) resulted in tissues that produced enhanced contractile responses to norepinephrine (NE) in isolated organ baths. Single challenges of NE (10 $\mu$M) produced 0.6 $\pm$ 0.1 g of maximal tension in the control vas whereas in the paired, denervated tissue 2.2 $\pm$ 0.3 g of tension was recorded (n = 6). Cumulative concentration-effect curves to NE produced in the denervated vas deferens were shifted 18-fold to the left of the control …

Differential Role Of The Endothelium In Regulating Microvascular Blood Flow, Tao Tang

Electronic Theses and Dissertations

The vascular endothelial cell (EC) plays an important role in regulating vascular tone and local blood flow by sensing chemical and mechanical stimuli on the vascular wall and releasing a host of vasoactive substances upon activations of endogenous or exogenous vasoactive substances. The central hypothesis is that local control of blood now and autoregulatory behavior in the microcirculation is distinctive at different levels of the vasculature and is dependent on the cellular activities of the EC and its interaction with the local environment. The in vivo as well as the ex vivo, flow-controlled preparations of the hamster cheek pouch were …

Characterization Of The Vasoactivity Of Tachykinins In Isolated Rat Kidney: Functional Studies And In Vitro Receptor Autoradiography, Yuejin Chen

Electronic Theses and Dissertations

Although tachykinins have potent vascular actions, their effect on renal resistance blood vessels is currently unknown. The vasoactive properties of tachykinins and related analogs were assessed in isolated perfused rat kidney. At a basal perfusion pressure (PP) of 75 $\pm$ 6 mm Hg (n = 5), bolus injections of substance P (SP) had no significant vasoactive effect. Following a sustained increase in baseline PP (134 $\pm$ 10 mm Hg) produced by phenylephrine (1 $\mu$M), SP evoked a dose-dependent increase in PP. The largest dose of SP increased PP by 60 $\pm$ 5 mm Hg. The vasoconstrictor response to SP was …

Production Of Interleukin 10 By Islet Cells Accelerates Immune-Mediated Destruction Of Beta Cells In Nonobese Diabetic Mice., Lise Wogensen, Myung-Shik Lee, Nora Sarvetnick

Journal Articles: Regenerative Medicine

The T helper type 2 (Th2) cell product interleukin 10 (IL-10) inhibits the proliferation and function of Th1 lymphocytes and macrophages (M phi). The nonobese diabetic mouse strain (NOD/Shi) develops a M phi and T cell-dependent autoimmune diabetes that closely resembles human insulin-dependent diabetes mellitus (IDDM). The objective of the present study was to explore the consequences of localized production of IL-10 on diabetes development in NOD/Shi mice. Surprisingly, local production of IL-10 accelerated the onset and increased the prevalence of diabetes, since diabetes developed at 5-10 wk of age in 92% of IL-10 positive I-A beta g7/g7, I-E- mice …

Pancreatic Islet Production Of Murine Interleukin-10 Does Not Inhibit Immune-Mediated Tissue Destruction., Myung-Shik Lee, Lise Wogensen, Judith Shizuru, Michael B.A. Oldstone, Nora Sarvetnick

Journal Articles: Regenerative Medicine

IL-10 inhibits macrophage-dependent antigen presentation, cytokine production, and generation of allospecific cells in vitro. These findings have lead to the widespread expectation that IL-10 may be a useful immunosuppressive agent to inhibit allograft rejection or autoimmunity in vivo. We used two experimental paradigms to study effects of murine IL-10 on in vivo immune responses. First, fetal pancreata or adult pancreatic islets from transgenic mice expressing IL-10 in pancreatic beta cells (Ins-IL-10 mice) were grafted across the MHC barrier to examine if IL-10 could inhibit allograft rejection. Second, Ins-IL-10 mice were crossed with transgenic mice expressing lymphocytic choriomeningitis virus (LCMV) antigens …

Binding Of Matrix Attachment Regions To Lamin Polymers Involves Single-Stranded Regions And The Minor Groove., M. E. Eva Ludérus, Jan L. Den Blaauwen, Oncko J. De Smit, Duane A. Compton, Roel Van Driel

Dartmouth Scholarship

Chromatin in eukaryotic nuclei is thought to be partitioned into functional loop domains that are generated by the binding of defined DNA sequences, named MARs (matrix attachment regions), to the nuclear matrix. We have previously identified B-type lamins as MAR-binding matrix components (M. E. E. Ludérus, A. de Graaf, E. Mattia, J. L. den Blaauwen, M. A. Grande, L. de Jong, and R. van Driel, Cell 70:949-959, 1992). Here we show that A-type lamins and the structurally related proteins desmin and NuMA also specifically bind MARs in vitro. We studied the interaction between MARs and lamin polymers in molecular detail …

G94-1220 Controlling Ticks, John B. Campbell, Gustave D. Thomas

University of Nebraska-Lincoln Extension: Historical Materials

Identification and control of ticks common to Nebraska.

Ticks are members of the same phylum (Arthropoda) of the animal kingdom as insects, but are in a different class (Arachnida). The main difference is the body of a tick is composed of only two sections while insect bodies have three sections.

There are over 800 species of ticks, 100 of which are important to man and animals because of economic losses or disease transmission. Fortunately in the United States, only about 12 species are economically important because they transmit disease organisms (viral, bacterial, protozoan, and rickettsial) or cause economic losses to …

G94-1231 Harvesting Corn And Sorghum For Silage, Rick Grant, Rick Stock

University of Nebraska-Lincoln Extension: Historical Materials

This publication describes how to make high-quality corn and sorghum silage.

Quality Silage

Silage feeding quality is determined by 1) the nutrient content of the crop stored, 2) the stage of maturity and moisture content when harvested and 3) the effectiveness of silage preservation.

G94-1198 Switchgrass And Big Bluestem For Grazing And Hay, Robert B. Mitchell, Lowell E. Moser, Bruce Anderson, Steven S. Waller

University of Nebraska-Lincoln Extension: Historical Materials

The grazing management and cultural practices discussed in this NebGuide can make switchgrass and big bluestem high quality summer forage. Switchgrass and big bluestem are native warm-season grasses that can provide abundant, high-quality forage during summer. Switchgrass and big bluestem produce 70 to 80 percent of their growth after June 1 in Nebraska, while more than 75 percent of cool-season grass growth, such as bromegrass and bluegrass, occurs before June 1. Therefore, switchgrass and big bluestem can provide forage to graze after cool-season pastures have been utilized. However, switchgrass and big bluestem must be managed differently than cool-season grasses. Poor …