scholarly journals Characterization of sodium‐glucose co‐transporters in the avian kidney

2006 ◽  
Vol 20 (5) ◽  
Author(s):  
Karen L. Sweazea ◽  
Giovanni Casotti ◽  
Eldon J. Braun
Keyword(s):  
Avian Kidney

Characterization of organic osmolytes in avian renal medulla: a nonurea osmotic gradient system

1993 ◽  
Vol 264 (6) ◽  
pp. R1045-R1049
Author(s):  
Y. H. Lien ◽  
M. M. Pacelli ◽  
E. J. Braun
Keyword(s):  
Water Deprivation ◽  
Renal Cortex ◽  
Renal Medulla ◽  
Urine Osmolality ◽  
Gradient System ◽  
Osmotic Gradient ◽  
Organic Osmolytes ◽  
Before And After ◽  
Avian Kidney

We measured the organic osmolytes present in the renal cortex and medullary cones of adult female domestic fowl before and after 48 h of water deprivation. Urine osmolality increased from 198 +/- 82 to 569 +/- 42 mosmol/kgH2O after water deprivation. In water-deprived birds, the major organic osmolytes, myoinositol, betaine, and taurine, in the medullary cones increased by 40, 100, and 24%, respectively, compared with control birds. No sorbitol was detected, and glycerophosphorylcholine (GPC) content was not affected by water deprivation. In the renal cortex, only betaine content increased significantly (4.8 +/- 0.6 vs. 3.1 +/- 0.3 mmol/kg wet wt) after water deprivation. In this study, we demonstrated that birds, like mammals, accumulate organic osmolytes in response to the increased interstitial osmolality that occurs during antidiuresis. Because urea is nearly absent in the avian medullary interstitium, our observation that GPC is not osmoregulated in the avian kidney supports the idea that GPC is the “counteracting osmolyte” for urea in the mammalian kidney. Furthermore, the organic osmolytes present in avian medullary cones are remarkably similar to those of the mammalian outer medulla. This similarity may be relevant to the morphological analogy of the two regions.

Characterization of organic cation transport by avian renal brush-border membrane vesicles

1995 ◽  
Vol 269 (5) ◽  
pp. R1050-R1059 ◽  
Author(s):  
A. R. Villalobos ◽  
E. J. Braun
Keyword(s):  
Brush Border ◽  
Brush Border Membrane ◽  
Organic Cation ◽  
Membrane Vesicles ◽  
Brush Border Membrane Vesicles ◽  
Organic Cations ◽  
Michaelis Constant ◽  
Renal Brush Border Membrane ◽  
Avian Kidney

Organic cations are actively secreted by the renal proximal tubule. Studies on perfused tubules and isolated membranes from mammals and reptiles have demonstrated that organic cations (OC) are transported across the luminal (brush-border) membrane by OC/H+ exchange. Our objective was to determine whether a similar mechanism was present in the avian kidney. Uptake of [14C]tetraethylammonium (TEA) was assayed under various ionic conditions by rapid filtration in brush-border membrane vesicles (BBMV) isolated from chicken kidney (Gallus domesticus). An outwardly directed proton gradient (pHin = 6.0: pHout = 7.5) stimulated concentrative TEA uptake. TEA/H+ exchange was saturable, having a maximal rate of uptake of approximately 25 nmol.mg protein-1.min-1 and a Michaelis constant for TEA of approximately 500 microM. TEA transport could be indirectly coupled to sodium transport. Unlabeled TEA, N'-methylnicotinamide (NMN), choline, cimetidine, mepiperphenidol, quinidine, quinine, and ranitidine markedly cis-inhibited uptake of [14C]TEA. However, the organic anions probenecid and p-aminohippurate poorly inhibited uptake. Unlabeled TEA and NMN also trans-stimulated [14C]TEA uptake. Thus, in avian renal BBMV, organic cations are transported by an OC/H+ exchange mechanism qualitatively similar to that present in mammals.

Diluting segment in avian kidney. I. Characterization of transepithelial voltages

1986 ◽  
Vol 250 (3) ◽  
pp. R333-R340 ◽  
Author(s):  
H. Nishimura ◽  
M. Imai ◽  
M. Ogawa
Keyword(s):  
Close Contact ◽  
Distal Tubule ◽  
Renal Tubules ◽  
Thick Ascending Limb ◽  
Diluting Segment ◽  
Cyanide Bath ◽  
Avian Kidney ◽  
Transepithelial Voltage

Renal tubules from the Japanese quail, Coturnix coturnix, were perfused in vitro to characterize the transepithelial voltage (Vt). The thick limb (TL) of the mammalian-type (MT) nephron showed Vt positive in the lumen (+9.1 +/- 0.7 mV, n = 35). The Vt decreased with increases in hydrostatic perfusion pressure. Furosemide (lumen), Na cyanide (bath), and ouabain (bath) reversibly reduced Vt. Removal of Cl or Na from the perfusate and the bath decreased Vt of the TL from +10.3 +/- 3.0 to -0.3 +/- 0.3 (n = 5) and from +7.4 +/- 1.5 to +1.2 +/- 0.2 mV (n = 8), respectively. The distal tubule of the reptilian-type (RT) nephron showed two types of Vt: a lumen-negative Vt in the late segment and a lumen-positive Vt in the early segment that is in close contact with the parent glomerulus. Both voltages were reversibly reduced by ouabain and Na cyanide. These results suggest that in quail the TL of the MT nephron resembles the thick ascending limb of the mammalian kidney with both Na and Cl required for generation of luminal positivity and the distal tubule of the RT nephron appears functionally heterogeneous.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

AEM analysis of crystallization in Ti-based amorphous alloys

1983 ◽  
Vol 41 ◽  
pp. 270-271
Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Amorphous Materials ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Nucleation And Growth ◽  
Current Interest ◽  
Amorphous Films ◽  
Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

Characterization of Coherent, Ordered Precipitates in Nickel-Base Alloys

1973 ◽  
Vol 31 ◽  
pp. 144-145
Author(s):  
B. H. Kear ◽  
J. M. Oblak
Keyword(s):  
Stable Phase ◽  
Nickel Base Superalloy ◽  
Alloy 718 ◽  
Commercial Alloy ◽  
Precipitate Morphology ◽  
Continuous Precipitation ◽  
Nickel Base ◽  
Base Superalloy ◽  
Strengthening Precipitate

A nickel-base superalloy is essentially a Ni/Cr solid solution hardened by additions of Al (Ti, Nb, etc.) to precipitate a coherent, ordered phase. In most commercial alloy systems, e.g. B-1900, IN-100 and Mar-M200, the stable precipitate is Ni3 (Al,Ti) γ′, with an LI2structure. In A lloy 901 the normal precipitate is metastable Nis Ti3 γ′ ; the stable phase is a hexagonal Do2 4 structure. In Alloy 718 the strengthening precipitate is metastable γ″, which has a body-centered tetragonal D022 structure.Precipitate MorphologyIn most systems the ordered γ′ phase forms by a continuous precipitation re-action, which gives rise to a uniform intragranular dispersion of precipitate particles. For zero γ/γ′ misfit, the γ′ precipitates assume a spheroidal.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Some applications of electron beam microanalysis techniques in VLSI process evaluation

1983 ◽  
Vol 41 ◽  
pp. 160-161
Author(s):  
Simon Thomas
Keyword(s):  
Integrated Circuits ◽  
Process Evaluation ◽  
Large Scale ◽  
Technology Development ◽  
Analytical Techniques ◽  
Successful Implementation ◽  
Analysis Of Failures ◽  
Characterization Of Materials ◽  
Circuits Vlsi

Trends in the technology development of very large scale integrated circuits (VLSI) have been in the direction of higher density of components with smaller dimensions. The scaling down of device dimensions has been not only laterally but also in depth. Such efforts in miniaturization bring with them new developments in materials and processing. Successful implementation of these efforts is, to a large extent, dependent on the proper understanding of the material properties, process technologies and reliability issues, through adequate analytical studies. The analytical instrumentation technology has, fortunately, kept pace with the basic requirements of devices with lateral dimensions in the micron/ submicron range and depths of the order of nonometers. Often, newer analytical techniques have emerged or the more conventional techniques have been adapted to meet the more stringent requirements. As such, a variety of analytical techniques are available today to aid an analyst in the efforts of VLSI process evaluation. Generally such analytical efforts are divided into the characterization of materials, evaluation of processing steps and the analysis of failures.

Irradiation behavior of pyrolytic silicon carbide

1983 ◽  
Vol 41 ◽  
pp. 72-73
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Products ◽  
Thermodynamics And Kinetics ◽  
Neutron Fluences ◽  
Fuel Particles ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of ◽  
Htgr Fuel

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

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