Nephroblastoma in a Common Mudpuppy Necturus maculosus simultaneously Present with a Mollicute Bacterium of the Genus Acholeplasma

2021 ◽  
Vol 33 (1) ◽  
pp. 44-52
Author(s):  
Isaac Standish ◽  
Eric Leis ◽  
Sara Erickson ◽  
Ryan Katona ◽  
Wes Baumgartner ◽  
...  
Keyword(s):  
Necturus Maculosus

scholarly journals Skull shape differentiation of black and white olms (Proteus anguinus anguinus and Proteus a. parkelj): an exploratory analysis with micro-CT scanning

2013 ◽  
Vol 82 (2) ◽  
pp. 107-114 ◽  
Author(s):  
Ana Ivanović ◽  
Gregor Aljančič ◽  
Jan W. Arntzen
Keyword(s):  
Morphological Differentiation ◽  
Ct Scanning ◽  
Exploratory Analysis ◽  
Micro Ct ◽  
Black And White ◽  
Necturus Maculosus ◽  
Proteus Anguinus ◽  
Evolutionary Trajectories ◽  
Morphological Detail ◽  
Shape Changes

We performed an exploratory analysis of the morphology of the cranium in the white olm (Proteus anguinus anguinus) and the black olm (P. a. parkelj) with micro-CT scanning and geometric morphometrics. The mudpuppy (Necturus maculosus) was used as an outgroup. The black olm falls outside the white olm morphospace by a markedly wider skull, shorter vomers which are positioned further apart and by laterally positioned squamosals and quadrates relative to the palate (the shape of the buccal cavity). On account of its robust skull with more developed premaxillae a shorter otico-occipital region, the black olm is positioned closer to Necturus than are the studied specimens of the white olm. The elongated skull of the white olm, with an anteriorly positioned jaw articulation point, could be regarded as an adaptation for improved feeding success, possibly compensating for lack of vision. As yet, the alternative explanations on the evolution of troglomorphism in Proteus are an extensive convergence in white olms versus the reverse evolution towards less troglomorphic character states in the black olm. To further understand the evolutionary trajectories within Proteus we highlight the following hypotheses for future testing: i) morphological differentiation is smaller within than between genetically differentiated white olm lineages, and ii) ontogenetic shape changes are congruent with the shape changes between lineages. We anticipate that the morphological detail and analytical power that come with the techniques we here employed will assist us in this task.

Dendritic integration in ganglion cells of the mudpuppy retina

1995 ◽  
Vol 12 (1) ◽  
pp. 165-175 ◽  
Author(s):  
T.J. Velte ◽  
R.F. Miller
Keyword(s):  
Functional Organization ◽  
Simulation Analysis ◽  
Ganglion Cells ◽  
Impedance Matching ◽  
Dendritic Tree ◽  
Membrane Resistance ◽  
Transient Responses ◽  
Dendritic Integration ◽  
Necturus Maculosus ◽  
Integration Efficiency

AbstractComputer simulations were carried out to evaluate the influence of varying the membrane resistance (Rm) on the dendritic integration capacity of three classes of ganglion cells in the mudpuppy (Necturus maculosus) retina. Three broadly different morphological classes of ganglion cells were selected for this study and represent the range of dendritic tree sizes found in the ganglion cell population of this species. Simulations were conducted on anatomical data obtained from cells stained with horseradish peroxidase; each cell was traced, using a computer as an entry device and later converted to a compartmental (electrical) representation of the cell. Computer-simulation analysis used a time-variant conductance change which was similar in waveform to light-activated bipolar cell input. The simulated membrane resistance for each cell varied between 5000 and 100,000 Ω cm2, and conductance changes were introduced into different regions of the soma-dendritic tree to evaluate dendritic integration efficiency. When higher values of Rm are used, even the largest cells become electrotonically compact and attenuation of voltage responses is minimized from distal to soma regions. Responses were less attenuated from proximal to distal regions of the cell because of the favorable impedance matching, and because less current is required to polarize small “sealed” dendritic terminations. Steady-state responses integrate more effectively than transient responses, particularly when Rm is high, since transient responses were more attenuated by the membrane capacitance. The possibility that Rm is a dynamic property of retinal ganglion cells is discussed in view of the functional organization of dendritic integration efficiency as Rm fluctuates from low to high values.

Single Proximal Tubules of the Necturus Kidney. II. Effect of 2,4-Dinitrophenol and Ouabain on Water Reabsorption

1958 ◽  
Vol 195 (3) ◽  
pp. 570-574 ◽  
Author(s):  
Hans J. Schatzmann ◽  
Erich E. Windhager ◽  
A. K. Solomon
Keyword(s):  
Proximal Tubule ◽  
Intravenous Administration ◽  
Proximal Tubules ◽  
Stopped Flow ◽  
Water Reabsorption ◽  
Necturus Maculosus ◽  
Flow Perfusion ◽  
Experimental Findings ◽  
Active Reabsorption ◽  
Normal Controls

The effect of ouabain and 2,4-dinitrophenol on water reabsorption from the proximal tubule of the kidney of Necturus maculosus has been studied using the collection and stopped flow perfusion techniques previously described. The intravenous administration of ouabain in collection experiments results in a decrease in water reabsorption from 32.7% (normal controls) to 15.4%. In stopped flow perfusion experiments on control animals, water reabsorption after 20 minutes is 27.2%. When 2,4-dinitrophenol or ouabain is added to the perfusion fluids, values of 10.2% and 9.8%, respectively, are observed. The experimental findings demonstrate that water reabsorption in the proximal tubule is inhibited by these agents. The results are in agreement with the hypothesis of active reabsorption of sodium from the proximal tubule of the kidney of Necturus.

Taste Cells in the Mudpuppy, Necturus maculosus, Are Electrically Coupled

1987 ◽  
Vol 510 (1 Olfaction and) ◽  
pp. 723-724 ◽  
Author(s):  
JIAN YANG ◽  
STEPHEN D. ROPER
Keyword(s):  
Necturus Maculosus ◽  
Taste Cells

Bumetanide and NaCl compete for transport sites in the early distal tubule of necturus maculosus

1988 ◽  
Vol 90 (4) ◽  
pp. 827
Author(s):  
B.-E Persson ◽  
T Sakai ◽  
M Ekblom ◽  
D.J Marsh
Keyword(s):  
Distal Tubule ◽  
Necturus Maculosus

Ammonia, Urea and H+ Distribution and the Evolution of Ureotelism in Amphibians

1989 ◽  
Vol 144 (1) ◽  
pp. 215-233 ◽  
Author(s):  
CHRIS M. WOOD ◽  
R. S. MUNGER ◽  
D. P. TOEWS
Keyword(s):  
Cell Membrane ◽  
Teleost Fish ◽  
Transmembrane Potential ◽  
Rana Catesbeiana ◽  
Ammonia Excretion ◽  
Cell Membrane Permeability ◽  
Ambystoma Tigrinum ◽  
Amphibian Species ◽  
Necturus Maculosus ◽  
Excretion Rates

In theory, the distribution of ammonia across cell membranes (Tammi/Tamme) between intracellular and extracellular fluids (ICF and ECF) may be determined by the transmembrane pH gradient (as in mammals), the transmembrane potential (as in teleost fish), or both, depending on the relative permeability of the membranes to NH3 and NH4+ (pNH3/pNH4+). The resting distributions of H+ (via [14C]DMO), ammonia and urea between plasma and skeletal muscle, and the relative excretion rates of ammonia-N and urea-N, were measured in five amphibian species (Bufo marinus, Ambystoma tigrinum, Rana catesbeiana, Necturus maculosus and Xenopus laevis). Although ureai/ureae ratios were uniformly close to 1.0, Tammi/Tamme. ratios correlated directly with the degree of ammoniotelism in each species, ranging from 9.1 (Bufo, 10% ammoniotelic) to 16.7 (Xenopus, 79% ammoniotelic). These values are intermediate between ratios of about 30 (low pNH3/pNH4+) in ammoniotelic teleost fish and about 3 (high pNH3/pNH4+) in ureotelic mammals. The results indicate that amphibians represent a transitional stage in which ammonia distribution is influenced by both the pHi-pHe gradient and the membrane potential, and that a reduction in cell membrane permeability to NH4+ (i.e. increased pNH3/pNH4+) was associated with the evolution of ureotelism. Hyperosmotic saline exposure increased urea excretion 10-fold in Xenopus, while ammonia excretion remained unchanged. Tammi/Tamme fell, but this response was attributable to an abolition of the pHi-pHe gradient, rather than a physiological change in the cell membrane pNH3/pNH4+.

Taste Receptor Cell Responses to the Bitter Stimulus Denatonium Involve Ca2+ Influx Via Store-Operated Channels

2002 ◽  
Vol 87 (6) ◽  
pp. 3152-3155 ◽  
Author(s):  
Tatsuya Ogura ◽  
Robert F. Margolskee ◽  
Sue C. Kinnamon
Keyword(s):  
Prolonged Exposure ◽  
Fluorescent Protein ◽  
Bitter Taste ◽  
Taste Receptor ◽  
Taste Receptor Cell ◽  
Cell Responses ◽  
Necturus Maculosus ◽  
Taste Cells ◽  
Intracellular Ca ◽  
Green Fluorescent

Previous studies in rat and mouse have shown that brief exposure to the bitter stimulus denatonium induces an increase in [Ca2+]i due to Ca2+ release from intracellular Ca2+ stores, rather than Ca2+influx. We report here that prolonged exposure to denatonium induces sustained increases in [Ca2+]i that are dependent on Ca2+ influx. Similar results were obtained from taste cells of the mudpuppy, Necturus maculosus, as well as green fluorescent protein (GFP) tagged gustducin-expressing taste cells of transgenic mice. In a subset of mudpuppy taste cells, prolonged exposure to denatonium induced oscillatory Ca2+responses. Depletion of Ca2+ stores by thapsigargin also induced Ca2+ influx, suggesting that Ca2+store-operated channels (SOCs) are present in both mudpuppy taste cells and gustducin-expressing taste cells of mouse. Further, treatment with thapsigargin prevented subsequent responses to denatonium, suggesting that the SOCs were the source of the Ca2+ influx. These data suggest that SOCs may contribute to bitter taste transduction and to regulation of Ca2+ homeostasis in taste cells.

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