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Jaerhyong Yoon - One of the best experts on this subject based on the ideXlab platform.

  • ultrastructural changes in the adrenal chromaffin cells and ganglion cells in the adrenal gland of Vacor induced diabetic mongolian gerbil
    Applied Microscopy, 1995
    Co-Authors: Jaehwang Park, Jaerhyong Yoon
    Abstract:

    The ultrastructural changes of adrenal chromaffin cells and ganglion cells in the adrenal gland of Vacor-induced diabetic Mongolian gerbils were studied by electron microscopy. After one month of Vacor-induced diabetes, some chromaffin cells were filled with dense bodies and large cytosomes with formy contents. Most of degenerating axon terminals were observed on chromaffin cells. A few macrophages were found among chromaffin cells at one month after induction. Several of these macrophages were filled with numerous phagosomes. After one month of Vacor-induced diabetes, the ganglion cells showed increase in numbers of dense bodies and degenerating dendrites compared with the normal ganglion cells. Both electron dense and lucent types of degenerating axon terminals were found in interstitial space of the ganglion cells. Degenerating unmyelinated and myelinted axons contained dense and lamellar bodies. The satellite cells and macrophages with engulfed degenerated axon terminals were observed. After three months of Vacor-induced diabetes, the unmyelinated and myelinated axons showed degenerative changes, whereas no structural changes could be demonstrated in adrenal ganglion and chromaffin cells. The satellite cells and macrophages containing partially digested debris were still commonly observed in the interstitial space of adrenal medulla. These results suggest that the degenerative changes occur in the adrenal ganglion cells as well as adrenal chromaffin cells of Vacor-induced diabetic Mongolian gerbils.

  • ultrastructural changes in the ganglion and granule containing cells in the heart of Vacor induced diabetic mongolian gerbil
    Applied Microscopy, 1993
    Co-Authors: Jungchaee Kang, Jaerhyong Yoon, Hongseok You
    Abstract:

    The ultrastructural changes of the cardiac ganglion and granule-containing cells in the heart of Vacor-induced diabetic Mongolian gerbils were studied by electron microscopy. After one month of Vacor-induced diabetes the ganglion cells showed increase in numbers of dense bodies and mitochondria compared with the normal cardiac ganglion. Most of the satellite cells were filled with numerous phagosomes containing digested debris. Both electron-dense and lucent types of degenerating axon terminals were observed. The former was characterized by clusters of agranular vesicles and numerous mitochondria. The electron lucent type of degenerating axon terminal contained a few agranular vesicles and swollen mitochondria. Degenerating unmyelinated and myelinated axons contained large numbers of dense bodies, lamellar bodies, and mitochondria. Numerous macrophages containing phagosomes were reveled in the interstitial spaces. Some of the granule-containing cells in the heart showed a variety of degenerative changes and a decreased number of dense-cored vesicles. After three months of Vacor-induced diabetes the unmyelinated and myelinated axons showed degenerative changes, whereas no structure changes could be demonstrated in intraatrial ganglion and granule containing cells. The satellite cells containing engulfed debris were observed in the cardiac ganglion cells. These results suggest that the degenerative changes occur in the cardiac ganglion cells of Vacor-induced diabetic Mongolian gerbils as well as atrial granule-containing cells.

Min Cheol Lee - One of the best experts on this subject based on the ideXlab platform.

  • Changes of Glomerular Basement Membrane Components in Vacor - Induced Diabetic Nephropathy
    The Korean Journal of Internal Medicine, 1999
    Co-Authors: Young Duk Seon, Tai Hee Lee, Min Cheol Lee
    Abstract:

    OBJECTIVES The thickening of the glomerular basement membrane in rats after Vacor ingestion was examined by electron microscopy. This study was performed to elucidate which biochemical components changed in the glomerular basement membrane after Vacor-induced diabetic glomerulopathy. METHODS Immunohistochemical analyses of type IV collagen, laminin, fibronectin and chondroitin sulfate proteoglycan were performed. A single dose of Vacor (molecular weight 272), 80 mg/kg, was administered to adult male Wistar rats by orogastric canule, and the animals were sacrificed at 0.5, 1, 3, 7, 14, 28 and 56 days after administration. RESULTS Mild thickening of the glomerular basement membrane was evident 7 days after Vacor administration, and the width of the glomerular basement membrane was more than twice that of normal controls at 28 and 56 days. Significantly increased expressions of type IV collagen, laminin, fibronectin and neutral polysaccharide in the thickened glomerular basement membrane were noted 14 to 56 days after administration, and a mildly increased expression of chondroitin sulfate proteoglycan appeared between 3 to 7 days. CONCLUSION These abnormally increased glomerular basement membrane components might be part of what causes diabetic nephropathy after Vacor administration.

  • Ultrastructure of neuromuscular junction in Vacor-induced diabetic rats.
    The Korean journal of internal medicine, 1998
    Co-Authors: Jae Su Ahn, Tai Hee Lee, Min Cheol Lee
    Abstract:

    Objectives Rodenticide Vacor causes a severe peripheral neuropathy in humans. Electrophysiologic studies on a peripheral motor nerve-skeletal system of Vacor-treated rat showed decreased amplitude of muscle action potential without conduction velocity abnormalities. The ultrastructural studies of the neuromuscular junction were performed to clarify the anatomic site of the Vacor-induced peripheral neuropathy in male Wistar rats.

Mark A. Myers - One of the best experts on this subject based on the ideXlab platform.

  • Inhibition of Mitochondrial Complex I May Account for IDDM Induced by Intoxication With the Rodenticide Vacor
    Diabetes, 1996
    Co-Authors: Mauro Degli Esposti, Anna Ngo, Mark A. Myers
    Abstract:

    Human intoxication with the rodenticide Vacor [ N -3-pyridylmethyl- N ′-p-nitrophenyl urea or 1-(4-nitrophenyl)-3-(3-pyridylmethyl) urea] induces acute IDDM. We report here that Vacor specifically inhibits the NADH:ubiquinone reductase activity of complex I in mammalian mitochondria. The activity of other respiratory enzymes of mitochondria is unaffected by Vacor at concentrations that completely inhibit the redox and energetic function of complex I. Vacor inhibition of complex I activity quantitatively correlates with the inhibition of insulin release in insulinoma cells and pancreatic islets and is also consistent with the doses reported in cases of human poisoning. These results indicate that the toxic and diabetogenic action of Vacor primarily derives from the inhibition of mitochondrial respiration of NAD-linked substrates in the high-energy demanding cells of the pancreatic islets. This newly identified mechanism of the pathological effects resulting from Vacor intoxication could constitute a paradigm in which to understand environmental or metabolic causes of IDDM.

Hongseok You - One of the best experts on this subject based on the ideXlab platform.

  • ultrastructural changes in the ganglion and granule containing cells in the heart of Vacor induced diabetic mongolian gerbil
    Applied Microscopy, 1993
    Co-Authors: Jungchaee Kang, Jaerhyong Yoon, Hongseok You
    Abstract:

    The ultrastructural changes of the cardiac ganglion and granule-containing cells in the heart of Vacor-induced diabetic Mongolian gerbils were studied by electron microscopy. After one month of Vacor-induced diabetes the ganglion cells showed increase in numbers of dense bodies and mitochondria compared with the normal cardiac ganglion. Most of the satellite cells were filled with numerous phagosomes containing digested debris. Both electron-dense and lucent types of degenerating axon terminals were observed. The former was characterized by clusters of agranular vesicles and numerous mitochondria. The electron lucent type of degenerating axon terminal contained a few agranular vesicles and swollen mitochondria. Degenerating unmyelinated and myelinated axons contained large numbers of dense bodies, lamellar bodies, and mitochondria. Numerous macrophages containing phagosomes were reveled in the interstitial spaces. Some of the granule-containing cells in the heart showed a variety of degenerative changes and a decreased number of dense-cored vesicles. After three months of Vacor-induced diabetes the unmyelinated and myelinated axons showed degenerative changes, whereas no structure changes could be demonstrated in intraatrial ganglion and granule containing cells. The satellite cells containing engulfed debris were observed in the cardiac ganglion cells. These results suggest that the degenerative changes occur in the cardiac ganglion cells of Vacor-induced diabetic Mongolian gerbils as well as atrial granule-containing cells.

Andreas Seidelmorgenstern - One of the best experts on this subject based on the ideXlab platform.

  • transport of butane in a porous vycor glass membrane in the region of condensation pressure
    Journal of Membrane Science, 2007
    Co-Authors: Petr Uchytil, R Petrickovic, Andreas Seidelmorgenstern
    Abstract:

    Abstract The transport and the separation efficiency in porous membranes can be strongly influenced by the condensation of permeating gases. An accurate experimental monitoring of permeating vapors and condensates in small pores of membranes is very desirable. The dynamic permeation method is one of the methods which can be used to perform a corresponding study. The following experimental arrangement was applied: a constant higher pressure P 1 was set on an open side of the membrane; on the opposite closed side the change of a lower pressure P 2 was measured. The dynamic permeation set-up was used at first in transport measurements of a noncondensable gas through a Vycor glass membrane (mean pore radius around 2 nm). The obtained data were compared with the results of alternatively performed steady state permeation measurements. Subsequently, the permeability was studied for the condensable gas butane through the Vycor glass membrane, particularly for elevator pressure conditions near the saturated vapor pressure. Also for this purpose the dynamic permeation experiment was found to be very convenient. It enables to measure the mass transport for very small pressure gradients across the membrane. The permeation results obtained correspond well with the liquid butane permeability of Vycor membrane quantified previously in independent pervaporation experiments. This agreement confirms the presence of liquid butane in small pores of Vycor glass during the transient gas transport at relatively high pressures.

  • Transport of butane in a porous Vycor glass membrane in the region of condensation pressure
    Journal of Membrane Science, 2007
    Co-Authors: Petr Uchytil, R Petrickovic, Andreas Seidelmorgenstern
    Abstract:

    The transport and the separation efficiency in porous membranes can be strongly influenced by the condensation of permeating gases. An accurate experimental monitoring of permeating vapors and condensates in small pores of membranes is very desirable. The dynamic permeation method is one of the methods which can be used to perform a corresponding study. The following experimental arrangement was applied: a constant higher pressure P1 was set on an open side of the membrane; on the opposite closed side the change of a lower pressure P2 was measured. The dynamic permeation set-up was used at first in transport measurements of a noncondensable gas through a Vycor glass membrane (mean pore radius around 2 nm). The obtained data were compared with the results of alternatively performed steady state permeation measurements. Subsequently, the permeability was studied for the condensable gas butane through the Vycor glass membrane, particularly for elevator pressure conditions near the saturated vapor pressure. Also for this purpose the dynamic permeation experiment was found to be very convenient. It enables to measure the mass transport for very small pressure gradients across the membrane. The permeation results obtained correspond well with the liquid butane permeability of Vycor membrane quantified previously in independent pervaporation experiments. This agreement confirms the presence of liquid butane in small pores of Vycor glass during the transient gas transport at relatively high pressures. Copyright © 2007 Elsevier B.V. All rights reserved. [accessed 2013 November 26th