scholarly journals ON THE DIFFERENTIAL RESPONSE OF SARCOPLASM AND MYOPLASM TO DENERVATION IN FROG MUSCLE

1965 ◽  
Vol 27 (1) ◽  
pp. 1-24 ◽  
Author(s):  
Umberto Muscatello ◽  
Alfredo Margreth ◽  
Massimo Aloisi
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Early Response ◽  
Frog Muscle ◽  
Active Synthesis ◽  
Electron Microscopic ◽  
Dynamic Changes ◽  
Initial Stage ◽  
Membrane Bound ◽  
Denervated Muscles ◽  
Tissue Fractionation

Electron microscopic evidence is presented that the early response to denervation ("simple atrophy") of the semitendinosus m. of the frog is characterized by a greater prominence of the sarcoplasmic reticulum and by the presence, in the interfibrillar spaces, of mitochondria which are more numerous and smaller than in normal muscle. In contrast with the dynamic changes of the sarcoplasmic structural components, the myofibrils showed a progressive decrease in diameter after denervation and throughout the period studied. By carrying out tissue fractionation experiments, the yield of microsome-protein was found significantly greater in the denervated muscles, as compared with the contralateral controls, in this initial stage. Under the conditions attending the overdevelopment of the sarcoplasmic reticulum (SR), denervated semitendinosus m. incorporated valine-C14 into proteins more actively than the control pairs. The denervated muscles also showed an increase in the number of freely scattered and membrane-bound ribosomes and of polyribosomes, suggesting a more active synthesis of the SR membranes. Pronounced atrophy of the myofibrils, disorganization of the SR, and an increased number of ribonucleoprotein particles lying in the enlarged interfibrillar spaces were the main ultrastructural features of "degenerative atrophy" in frog muscle in the late periods after denervation. The probably adaptive character of the early changes occurring on denervation of frog muscle is discussed.

A Reproducible Selective Stain for Cardiac Sarcoplasmic Reticulum

1974 ◽  
Vol 32 ◽  
pp. 214-215
Author(s):  
R. A. Waugh ◽  
J. R. Sommer
Keyword(s):  
Complex System ◽  
Electron Microscope ◽  
Sarcoplasmic Reticulum ◽  
Transmission Electron Microscope ◽  
Electron Microscopic ◽  
Cardiac Sarcoplasmic Reticulum ◽  
Transmission Electron

Cardiac sarcoplasmic reticulum (SR) is a complex system of intracellular tubules that, due to their small size and juxtaposition to such electron-dense structures as mitochondria and myofibrils, are often inconspicuous in conventionally prepared electron microscopic material. This study reports a method with which the SR is selectively “stained” which facilitates visualizationwith the transmission electron microscope.

An Electron Microscopic Study of the Acute Effects of Hypothalamic Releasing Factors on the Anterior Pituitary Gland

1968 ◽  
Vol 26 ◽  
pp. 232-233
Author(s):  
P.W. Coates ◽  
E.A. Ashby ◽  
L. Krulich ◽  
A. Dhariwal ◽  
S. McCann
Keyword(s):  
Anterior Pituitary ◽  
Microscopic Investigation ◽  
Uranyl Acetate ◽  
Electron Microscopic Investigation ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Thin Sections ◽  
Dense Membrane ◽  
Membrane Bound ◽  
Releasing Factors

The morphologic effects on somatotrophs of crude sheep hypothalamic extract prepared from stalk-median eminence were studied by electron microscopy in conjunction with concurrently run bioassays performed on the same tissue samples taken from young adult male Sherman rats.Groups were divided into uninjected controls and injected experimentals sacrificed at 5', 15', and 30' after injection. Half of each anterior pituitary was prepared for electron microscopic investigation, the other half for bioassay. Fixation using collidine buffered osmium tetroxide was followed by dehydration and embedment in Maraglas. Uranyl acetate and lead citrate were used as stains. Thin sections were examined in a Philips EM 200.Somatotrophs from uninjected controls appeared as described in the literature (Fig. 1). In addition to other components, these cells contained moderate numbers of spherical, electron-dense, membrane-bound granules approximately 350 millicrons in diameter.

Microscopic investigations of novel intracellular bodies of a Nocardia SP

1994 ◽  
Vol 52 ◽  
pp. 356-357
Author(s):  
J. L. Stites
Keyword(s):  
Uranyl Acetate ◽  
Electron Microscopic ◽  
En Bloc ◽  
Ribonucleic Acids ◽  
Transmission Electron ◽  
Nocardia Sp ◽  
Internal Constitution ◽  
Membrane Bound ◽  
Molecular Components ◽  
Protein Rich

A Nocardia sp.was found during an initial transmission electron microscopic (TEM) examination to have unusual intracellular bodies (ICB's) which do not appear to have been described previously in the literature. Most intracellular structures within bacteria have been classified as storage granules, a product of membrane invagination (i.e. mesosomes), or vacuoles. In bacteria there are no known intracellular membrane-bound organelles, and all internal membranes are invaginations of the unit membrane. Several microscopic-level examinations of the Nocardia sp. ICB's were initiated in order to determine their overall structure, classification, and internal constitution.Different TEM staining procedures were performed to determine possible molecular components of the ICB. In all of the staining protocols the ICB's showed a lack of electron density similar to the cell wall. Because the ICB's showed no affinity to any stain, it appeared they do not have strong positive charge (phosphotungstic acid), are not protein rich (en bloc uranyl acetate), lack glycogen and are not phosphate or sulphur rich (lead citrate), nor do they contain lipids or ribonucleic acids (osmium tetroxide).

Ultrastructural Study of Apocrine Differentiation in Human Mammary Carcinoma: Correlation of Granule Content With Sex Steroid Binding

1980 ◽  
Vol 38 ◽  
pp. 742-743
Author(s):  
S. E. Levine ◽  
A. D. Brinkhous ◽  
K. S. McCarty ◽  
J. A. Mossier ◽  
K.S. McCarty
Keyword(s):  
Ultrastructural Study ◽  
Ductal Carcinoma ◽  
Apocrine Carcinoma ◽  
Electron Microscopic ◽  
Granular Eosinophilic Cytoplasm ◽  
Eosinophilic Cytoplasm ◽  
Apocrine Differentiation ◽  
Microscopic Features ◽  
Membrane Bound ◽  
Epithelial Lesions

A variant of ductal carcinoma of the human breast which has been designated apocrine carcinoma has distinctive light and electron microscopic features. Such tumors comprise approximately 0.5% of breast carcinomas. Abundant cytoplasmic membrane bound vesicles (400-600 nm) with dense homogeneous osmophilic cores characterize these tumors. These granules are also seen in apocrine metaplastic breast epithelial lesions1 and appear to be responsible for the finely granular eosinophilic cytoplasm observed by light microscopy. A high content of intermediate affinity non-saturable 4S progesteroneestrogen binding protein (PEBP) in apocrine carcinoma has been reported.2 The present ultrastructural study evaluates the presence of apocrine granules in infiltrating ductal carcinoma (NOS) to determine if a correlation exists between apocrine granule content and the quantity of PEBP present.

scholarly journals PROBLEMS ASSOCIATED WITH THE DEMONSTRATION BY LEAD METHODS OF ADENOSINE TRIPHOSPHATASE ACTIVITY IN RESIDENT PERITONEAL MACROPHAGES AND EXUDATE MONOCYTES OF THE GUINEA PIG

1973 ◽  
Vol 21 (5) ◽  
pp. 488-498 ◽  
Author(s):  
R. E. POELMANN ◽  
W. T. DAEMS ◽  
E. J. VAN LOHUIZEN
Keyword(s):  
Plasma Membrane ◽  
Guinea Pig ◽  
Microscopic Study ◽  
Heterogeneous Nucleation ◽  
Adenosine Triphosphatase ◽  
Peritoneal Macrophages ◽  
Electron Microscopic ◽  
Adenosine Triphosphatase Activity ◽  
Eosinophilic Granulocytes ◽  
Membrane Bound

This cytochemical and electron microscopic study on peritoneal macrophages of the guinea pig has raised doubts concerning the validity of lead methods for the demonstration of plasma membrane-bound adenosine triphosphatase activity. The problems encountered are inherent in the use of lead ions as a capture reagent. The nonenzymatically formed precipitates reflect sites of heterogeneous nucleation specific for certain kinds of cells, e.g., resident peritoneal macrophages, eosinophilic granulocytes and, to a lesser degree, exudate monocytes. This type of precipitation is also catalyzed on the surface of nonbiologic matrices such as latex particles. Enzymatic processes may well occur, but they cannot be distinguished from nonenzymatic processes.

Monosaccharides and Disaccharides Decrease the K m for Phosphorylation of a Membrane-Bound Enzyme ATPase

1991 ◽  
Vol 46 (7-8) ◽  
pp. 644-646 ◽  
Author(s):  
Eduardo N. Chini ◽  
José Roberto Meyer-Fernandes ◽  
Mauro Sola-Penna
Keyword(s):  
Sarcoplasmic Reticulum ◽  
G Protein ◽  
Membrane Bound

Abstract The disaccharides trehalose and sucrose, and to a lesser extent the monosaccharides glucose and fructose, decrease the apparent Km of the Ca2+,Mg2+-ATPase of sarcoplasmic reticulum for Pi. This effect is more pronounced at pH 7.4 than at pH 6.2. The enzyme is not phosphorylated by Pi when the temperature of the medium is decreased to 0 °C, but when 1.5 ᴍ trehalose or sucrose is present phosphoenzyme formation increases to 0.5 nmol E-P/g protein.

Local ATP regeneration is important for sarcoplasmic reticulum Ca2+ pump function

1994 ◽  
Vol 267 (2) ◽  
pp. C357-C366 ◽  
Author(s):  
P. Korge ◽  
K. B. Campbell
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Atpase Activity ◽  
Muscle Relaxation ◽  
Creatine Phosphate ◽  
Coupling Ratio ◽  
Pump Function ◽  
Membrane Bound ◽  
Low Efficiency ◽  
Atp Regeneration ◽  
Assay Conditions

Ca2+ pump function of skeletal muscle sarcoplasmic reticulum (SR) vesicles was measured by monitoring Ca2+ uptake and efflux with a Ca(2+)-sensitive minielectrode and adenosinetriphosphatase (ATPase) activity of the same preparation under the same conditions. The efficiency of Ca2+ transport into SR vesicles, defined by the amount of Ca2+ transported per ATP hydrolyzed (coupling ratio), varied significantly depending on assay conditions. Coupling ratio increased in parallel with increase in precipitating anion concentration, which is supposed to decrease accumulation of free Ca2+ inside vesicles and its subsequent efflux. Membrane-bound creatine kinase-creatine phosphate (CK-CP) system, acting as a ADP sensor and local ATP regenerator, significantly improved Ca2+ pump function when the pump worked with low efficiency (coupling ratio < 1). The effect of CK-CP system on Ca2+ pump function was also dependent on extravesicular Ca2+ concentration ([Ca2+]o), the effect being most significant at high initial [Ca2+]o. Under conditions in which SR vesicles were allowed to decrease [Ca2+]o, as occurs also during muscle relaxation, plateau values of Ca(2+)-ATPase activity were reached at significantly higher [Ca2+]o (54 +/- 5.7, n = 6), compared with leaky vesicles or the condition in which [Ca2+]o was maintained. By preventing local accumulation of ADP, generated in ATPase reactions, CK-CP system also inhibited Ca2+ efflux under conditions in which this efflux was stimulated by the increase of free Ca2+ inside vesicles. This effect was at least partially responsible for the CK-CP-supported increase in Ca2+ uptake and coupling ratios that were more expressed at low precipitating anion concentration. We hypothesize that local ATP regeneration by CK-CP system is one mechanism the cell can use to improve Ca2+ uptake by SR in emergency conditions, where excessive increase in cytoplasmic [Ca2+] may have deleterious effects.

scholarly journals Ultra-fine features of aerohaematic barrier in pneumoconiosis

2008 ◽  
pp. 77-79
Author(s):  
G. G. Kruglikov ◽  
B. T. Velichkovsky
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Blood Flow ◽  
Early Response ◽  
Dust Exposure ◽  
Pulmonary Capillaries ◽  
Initial Stage ◽  
Scanning Electron

Combined implication of optical, transmissive and scanning electron microscopy allowed detection of early response to dust exposure: slowing of blood flow and dilation of pulmonary capillaries, oedema and initial stage of fibrillogenesis in aerohaematic barrier.

A Rare Case of Hermansky-Pudlak Syndrome Involving Bilateral Lung: Histopathologic and Electron Microscopic Findings

2019 ◽  
Vol 152 (Supplement_1) ◽  
pp. S42-S43
Author(s):  
Atreyee Basu ◽  
Surya Seshan ◽  
Luis Angel ◽  
Andre Moreira ◽  
Fang Zhou
Keyword(s):  
Alveolar Macrophages ◽  
Lamellar Body ◽  
Oculocutaneous Albinism ◽  
Electron Microscopic ◽  
Restrictive Lung Disease ◽  
Breath Sounds ◽  
Membrane Bound ◽  
Hermansky Pudlak Syndrome ◽  
Bilateral Lung ◽  
End Stage

Abstract Introduction Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive hereditary disorder characterized by oculocutaneous albinism and bleeding diathesis. Transplantation is often conducted to treat lung fibrosis, which is the most fatal complication of this disease. While the literature discusses the diagnosis of HPS based on genetic testing, radiology, and electron microscopic (EM) findings of platelet granules, there is a paucity of images in the literature illustrating the pulmonary histopathologic and EM features of HPS. Case Report Here we present striking histopathologic and EM images from a case of pulmonary fibrosis due to HPS in a 48-year-old female. The patient presented with restrictive lung disease and bilateral decreased breath sounds with diffuse crackles. She was clinically diagnosed with HPS and underwent bilateral lung transplant. On histopathology, both pneumonectomy specimens showed diffuse interstitial fibrosing and cellular pneumonitis with end-stage remodeling and type II pneumocyte (PC-II) hyperplasia. The PC-IIs had abundant foamy cytoplasm and compressed scalloped nuclei. Alveolar macrophages contained fine brown granules positive for PAS-D stain. EM analysis revealed that the PC-IIs contained numerous lamellated myelin bodies (so-called giant lamellar body degeneration) suggestive of surfactant admixed with lipid and luminal microvilli. The pigmented alveolar macrophages also contained lamellated myelin bodies, as well as clusters of single membrane-bound structures with varying size and electron density admixed with vacuolar and granular debris suggestive of ceroid deposits. Conclusion Based on light microscopy, histochemical analysis, EM, and clinical presentation, it was concluded that our findings were consistent with pulmonary changes as seen in HPS.

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