Salivary Calculi: Ultrastructural Morphology and Bacterial Etiology

1981 ◽  
Vol 60 (8) ◽  
pp. 1386-1395 ◽  
Author(s):  
J. Lustmann ◽  
A. Shteyer
Keyword(s):  
Ultrastructural Morphology ◽  
Salivary Calculi

A Comparison of the Ultrastructural Morphology of Hepatic Necrosis in BDF1 Mice

1981 ◽  
Vol 39 ◽  
pp. 586-587
Author(s):  
Becky Jackson
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
Preliminary Investigation ◽  
Hepatic Necrosis ◽  
Hepatic Tissue ◽  
Pronounced Increase ◽  
Glycogen Store ◽  
Ultrastructural Morphology ◽  
Mitochondrial Integrity ◽  
Glycogen Stores

Preliminary investigation has indicated similarity in hepatic ultrastructural morphology in nutritional deprivation, and cyanide induced hepatic necrosis. Analysis of hepatic tissue has indicated disruption of intracellular membranes, specifically, reduction in rough endoplasmic reticulum (RER) mitochondrial integrity, and glycogen stores. An increase in smooth endoplasmic reticulum (SER) portion was observed.To further investigate the apparent equivalence of necrotic morphology, ultrastructura1ly, BDF1 mice were subjected to senescence, nutritional deprevation, potassium cyanide (KCN) induced toxemia, and acetaminophen induced toxemia. Controls were utilized to ellucidate non-necrotic hepatocellular normals. U1trastructura1 investigation of controls (Fig. 1) shows densely granular RER, abundant glycogen stores, and morphologically normal mitochondria. Subjects with acetaminophen induced necrosis exhibit reduced normal RER with increased levels of dialated, vesicular RER in apparent conversion to SER (Fig. 2), loss of mitochondrial integrity, and glycogen store reduction. Senescent subjects exhibit a pronounced increase in SER and loss of glycogen store. (Fig. 3). Investigation of the senescent SER at high magnification (Fig. 5) indicates that the SER is arising from degranulating and vesiculating RER.

Ultrastructural morphology of nontumorous lactotrophs in human pituitaries exposed to high prolactin levels

1987 ◽  
Vol 45 ◽  
pp. 896-897
Author(s):  
S. Jalalah ◽  
K. Kovacs ◽  
E. Horvath
Keyword(s):  
Anterior Pituitary ◽  
Secretory Activity ◽  
Pituitary Hormones ◽  
Feedback Mechanism ◽  
Endocrine Activity ◽  
Hormone Synthesis ◽  
Anterior Pituitary Hormones ◽  
Negative Feedback Mechanism ◽  
Ultrastructural Morphology ◽  
Transmission Electron

Lactotrophs, as many other endocrine cells, change their morphology in response to factors influencing their secretory activity. Secretion of prolactin (PRL) from lactotrophs, like that of other anterior pituitary hormones, is under the control of the hypothalamus. Unlike most anterior pituitary hormones, PRL has no apparent target gland which could modulate the endocrine activity of lactotrophs. It is generally agreed that PRL regulates its own release from lactotrophs via the short loop negative feedback mechanism exerted at the level of the hypothalamus or the pituitary. Accordingly, ultrastructural morphology of lactotrophs is not constant; it is changing in response to high PRL levels showing signs of suppressed hormone synthesis and secretion.By transmission electron microscopy and morphometry, we have studied the morphology of lactotrophs in nontumorous (NT) portions of 7 human pituitaries containing PRL-secreting adenoma; these lactotrophs were exposed to abnormally high PRL levels.

Matrix-Mineral Relationships-A. Morphologist's Viewpoint

1979 ◽  
Vol 58 (2_suppl) ◽  
pp. 922-929 ◽  
Author(s):  
M.U. Nylen
Keyword(s):  
Organic Material ◽  
Crucial Role ◽  
Crystal Surface ◽  
Organic Matrix ◽  
The Other ◽  
Enamel Matrix ◽  
Initial Cell ◽  
Cell Product ◽  
Ultrastructural Morphology ◽  
The Matrix

The literature on the ultrastructural morphology of the enamel matrix and its relationship to the crystals is reviewed. Two morphological entities of the matrix are discussed: One is the so-called stippled material which may be the initial cell product; the other, variously described as fibrillar, lamellar, tubular or helical, is thought by many to play a crucial role in nucleation and orientation of the crystals. A number of observations, however, suggest that the latter structures form secondarily to the crystals and that in reality they represent organic material adsorbed to the crystal surface and maintained as independent structures upon removal of the mineral. The need for additional studies is stressed including systematic studies of interactions between constituents of the organic matrix and the apatite crystals.

New data on Myxobolus imparfinis (Cnidaria, Myxosporea): host, distribution, and ultrastructural morphology

2019 ◽  
Vol 118 (6) ◽  
pp. 1967-1973 ◽  
Author(s):  
Lidiane Franceschini ◽  
Diego Henrique Mirandola Dias Vieira ◽  
Aline Cristina Zago ◽  
Rodney Kozlowiski Azevedo ◽  
Vanessa Doro Abdallah ◽  
...  
Keyword(s):  
Ultrastructural Morphology ◽  
Host Distribution

Nippostrongylus brasiliensis: further properties of antibody-damaged worms and induction of comparable damage by maintaining worms in vitro

Parasitology ◽  
1975 ◽  
Vol 71 (2) ◽  
pp. 275-283 ◽  
Author(s):  
R. J. Love ◽  
Bridget M. Ogilvie ◽  
Diane J. McLaren
Keyword(s):  
Immune Response ◽  
Isoenzyme Pattern ◽  
Nippostrongylus Brasiliensis ◽  
Ultrastructural Morphology ◽  
Immature Rats ◽  
Normal Rat ◽  
Worm Expulsion ◽  
Anterior Migration

When adult Nippostrongylus brasiliensis were maintained in vitro they became damaged. Using the criteria of ultrastructural morphology, acetylcholinesterase isoenzyme pattern and the behaviour of the worms after transfer to a normal rat, this damage appeared to be similar to that produced by the in vivo action of antibodies.Antibodies were shown to be responsible for the anterior migration of adult worms which occurs during primary infections in mature rats and in the prolonged infections seen in lactating and immature rats.Antibody damaged worms and worms unaffected by antibodies were equally able to stimulate the immune response required for worm expulsion. Apparently antibody damage is not required for the initiation of the second immune component necessary for expulsion of this parasite.

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