Seasonal cytological changes in secondary phloem parenchyma cells in Robinia pseudoacacia in relation to cold hardiness

1971 ◽  
Vol 49 (5) ◽  
pp. 787-795 ◽  
Author(s):  
M. K. Pomeroy ◽  
D. Siminovitch
Keyword(s):  
Endoplasmic Reticulum ◽  
Frost Resistance ◽  
Cold Hardiness ◽  
Starch Content ◽  
Robinia Pseudoacacia ◽  
Electron Microscopic ◽  
Phloem Parenchyma ◽  
Parenchyma Cells ◽  
Microscopic Studies ◽  
Cytological Changes

Electron microscopic studies of cytological changes in phloem parenchyma cells of the living bark of black locust, Robinia pseudoacacia L., indicate that seasonal augmentation in total protoplasm, including mitochondria, lipid bodies, and, particularly, membrane-bound vesicles derived from invaginations and folding of the plasmalemma are closely related to the seasonal cycle of frost resistance. The structural organization of the endoplasmic reticulum also varies seasonally. In summer it is present as long cisternae-like units, which, during autumn and winter, appear to be replaced by a vesicular form of endoplasmic reticulum. Starch content does not appear to be closely related to initiation of the hardening process, but maximum hardiness is not developed until nearly all of the starch has disappeared from the cells. The observations support the view that the total expression of frost resistance in plant cells involves participation of the following three mechanisms: (1) augmentation of total protoplasm, extending to organelles, surface membranes, and other structural components of the cell; (2) lipid transformations; and (3) starch–sugar transformations.

scholarly journals Cytological changes in phloem parenchyma cells of Solanum rostratum (Dunal.) related to the replication of potato virus M (PVM)

2014 ◽  
Vol 59 (1-4) ◽  
pp. 45-53 ◽  
Author(s):  
Anna Rudzińska-Langwald
Keyword(s):  
Endoplasmic Reticulum ◽  
Potato Virus ◽  
Coated Particles ◽  
Virus Particles ◽  
Phloem Parenchyma ◽  
Solanum Rostratum ◽  
Parenchyma Cells ◽  
Potato Virus M ◽  
Cytological Changes

The first cytological symptom of infection of phloem parenchyma cells by potato virus M is the formation of clusters of endoplasmic reticulum cisterns in a cytoplasm containing numerous ribosomes. Randomly distributed PVM particles are found in the vicinity of the cisterns. As the infection progresses, inclusions made up of regularly arranged particles of PVM are formed.The cytoplasm of the cells becomes electron transparent because the ER cisterns disappear. Masses of homogenous substances containing single PVM particles appear. There are two types of deposits in the inclusions containing PVM virus particles - additionally coated particles and tubules.

Hepatic Ultrastructure Changes Induced by Lithocholic Acid

1967 ◽  
Vol 25 ◽  
pp. 162-163 ◽  
Author(s):  
F. G. Zaki
Keyword(s):  
Endoplasmic Reticulum ◽  
Lithocholic Acid ◽  
Smooth Endoplasmic Reticulum ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Electron Microscopic ◽  
Hydropic Degeneration ◽  
Hepatic Cells ◽  
Low Protein ◽  
Microscopic Studies

Addition of lithocholic acid (LCA), a naturally occurring bile acid in mammals, to a low protein diet fed to rats induced marked inflammatory reaction in the hepatic cells followed by hydropic degeneration and ductular cell proliferation. These changes were accompanied by dilatation and hyperplasia of the common bile duct and formation of “gallstones”. All these changes were reversible when LCA was withdrawn from the low protein diet except for the hardened gallstones which persisted.Electron microscopic studies revealed marked alterations in the hepatic cells. Early changes included disorganization, fragmentation of the rough endoplasmic reticulum and detachment of its ribosomes. Free ribosomes, either singly or arranged in small clusters were frequently seen in most of the hepatic cells. Vesiculation of the smooth endoplasmic reticulum was often encountered as early as one week after the administration of LCA (Fig. 1).

Spermatogenesis in the Dragonfly with Particular Reference to the Cytoplasmic Organelles

1972 ◽  
Vol 30 ◽  
pp. 110-111
Author(s):  
Sant S. Sekhon
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Mature Sperm ◽  
Electron Microscopic ◽  
Cytoplasmic Organelles ◽  
Microscopic Studies ◽  
Insect Sperm ◽  
Large Round

Although there have been numerous studies concerning the morphogenetic changes accompanying the maturation of insect sperm, only a few deal with the sperm differentiation in the dragonflies. In two recent electron microscopic studies Kessel, has comprehensively treated the erlationship of microtubules to the nucleus and mid-piece structures during spermiogenesis in the dragonfly. The purpose of this study is to follow the sequential nuclear and cytoplasmic changes which accompany the differentiation of spermatogonium into a mature sperm during spermatogenesis in the dragonfly (Aeschna sp.).The dragonfly spermatogonia are characterized by large round nuclei. Loosely organized chromatin is usually unevenly distributed within the spermatogonial nuclei. The scant cytoplasm surrounding the nucleus contains mitochondria, the Golgi apparatus, elements of endoplasmic reticulum and numerous ribosomes (Fig. 1).

scholarly journals ELECTRON MICROSCOPY OF THE BURSA OF FABRICIUS OF THE EMBRYONIC CHICK WITH PARTICULAR REFERENCE TO THE LYMPHO-EPITHELIAL NODULES

1962 ◽  
Vol 13 (1) ◽  
pp. 127-146 ◽  
Author(s):  
G. Adolph Ackerman
Keyword(s):  
Endoplasmic Reticulum ◽  
Epithelial Cells ◽  
Embryonic Development ◽  
Golgi Complex ◽  
Bursa Of Fabricius ◽  
Cortical Region ◽  
Electron Microscopic ◽  
Submicroscopic Structure ◽  
Microscopic Studies ◽  
Pass Through

Electron microscopic studies of the bursa of Fabricius during the 15th and 16th day of embryonic development in the chick have shown the following findings in the submicroscopic structure of the cellular elements of the lympho-epithelial follicles. In the medulla, basal endodermal epithelial cells undergo mitosis and differentiation into lymphoblasts. During this transformation, there is a reduction in the amount of rough endoplasmic reticulum, an increase in the number or ribosomes, and frequently an enlargement of the Golgi complex. As lymphoblasts differentiate into medium lymphocytes there is a loss of endoplasmic reticulum, a reduction in the number of ribosomes and in the size of the Golgi complex, as well as a decrease in the number and size of mitochondria and in the size of the cell and nucleus. Cytoplasmic processes of reticular-epithelial cells extend between proliferating lymphocytic cells. Desmosomes connect stellate reticular-epithelial and basal epithelial cells but are not present in lymphocytic cells. Nuclear blebbing and vesiculation are frequently observed in the various cell forms of the developing lympho-epithelial nodules. Although lymphocytes and lymphocytopoietic activities in the cortex are sparse during this stage of embryonic development of the bursa, transitional forms between mesenchymal cells and lymphoblasts have been encountered. In addition, lymphoblasts and/or undifferentiated epithelial cells occasionally may pass through the basement membrane from the medulla into the cortical region of the developing nodule. That lymphocytes in the bursa of Fabricius originate from both endodermal and mesodermal derivatives during embryonic development appears to be consistent with both light and electron microscopic observations.

Alveolate Reticulum - An Alteration of Endoplasmic Reticulum Observed in Human Tissues

1970 ◽  
Vol 28 ◽  
pp. 88-89
Author(s):  
Betty G. Uzman ◽  
Marjorie Kasac
Keyword(s):  
Endoplasmic Reticulum ◽  
Lymph Node ◽  
Single Cell ◽  
Secretory Cell ◽  
Leukemic Cells ◽  
Human Tissues ◽  
Malignant Histiocytosis ◽  
Electron Microscopic ◽  
Phase Microscopy ◽  
Microscopic Studies

Electron microscopic studies of human tumors have been correlated by phase microscopy of ∼1μ sections with conventional histopathology. In tumor nodules from patients with fibrosarcoma (Fig. 1), malignant histiocytosis, and Hodgkin's disease (Figs. 2, 3, 4); in leukemic cells infiltrating spleen and lymph node; and in one parotid secretory cell (case of acute myeloblastic leukemia) alterations of the granular endoplasmic reticulum have been observed. These structures (indicated by arrows) resemble moth-eaten membranous bodies continuous with the encircling (Figs. 1, 2) or contiguous (Figs. 3, 4) cisternal wall. As many as five such alveolate reticular regions have been observed in a single cell.

An Electron Microscopic Study of the Human Gastric Epithelia with Special Reference to the Cardinal Morphological Changes of the Chief Cells Induced by Insulin Stimulus

1972 ◽  
Vol 30 ◽  
pp. 344-345
Author(s):  
Hiroshi Saito ◽  
Goro Asano ◽  
Kaoru Aihara ◽  
Katsunari Fukushi ◽  
Minoru Yoshida ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Morphological Changes ◽  
Regular Insulin ◽  
Endoscopic Biopsy ◽  
Granular Endoplasmic Reticulum ◽  
Ultrastructural Changes ◽  
Electron Microscopic ◽  
Chief Cells ◽  
Microscopic Studies ◽  
The One

This short communication is dealt with the ultrastructural changes of the chief cells in insulin stimulus in chronic gastritic condition. The bio gastro-endoscopic biopsy was obtained and pepsin activity of the gastric juice was measured in respective cases. Regular insulin of 0.15U/kg was administrated intra-muscularly and in pre-administration of insulin, 10 minutes, 20 minutes and 30 minutes after administration, biopsied specimens were subjected for electron microscopic studies.In the pre-treated chief cells, extensive development of the cysternal structures of the granular endoplasmic reticulum in basal aspect of the cytoplasm and spherical or oval shaped, light homogeneous zymogen granules in supranuclear region and especially apical aspect of the cytoplasm were featured. Moreover, other type of the chief cells as the one characterized by their fragmented and saccular dilated granular endoplasmic reticulum in basal aspect of the cytoplasm, also exist.

Sugar beet petiole structure: vascular anastomoses and phloem ultrastructure

1985 ◽  
Vol 63 (12) ◽  
pp. 2295-2304 ◽  
Author(s):  
John W. Oross ◽  
William J. Lucas
Keyword(s):  
Endoplasmic Reticulum ◽  
Sugar Beet ◽  
Vascular Anatomy ◽  
Initial Contact ◽  
Lateral Movement ◽  
Sieve Elements ◽  
Phloem Parenchyma ◽  
Microfilament Bundles ◽  
Companion Cells ◽  
Parenchyma Cells

The vascular anatomy and phloem ultrastructure of the sugar beet petiole were studied in an attempt to evaluate the potential of petiolar phloem anastomoses to accommodate lateral movement of translocates across this structure. Clearings revealed that six of the eight interveinal regions between the nine major, axially oriented veins were connected by many anastomoses. The two interveinal areas characterized by the fewest anastomoses were located near the margin of the petiole. It was concluded that lateral translocation via anastomoses would be most efficient in the central part of the petiole. A light microscope study of the structure of the junction between anastomosing and continuous veins revealed that the sieve elements of each of the merging veins were separated from each other, for distances of up to 6 mm beyond the point of initial contact, by phloem parenchyma cells. The presence of phloem parenchyma cells in this position, and between the clusters of sieve elements that occur across the phloem of the large bundles, was taken as an indication that the parenchyma cells may have an important role in lateral translocation. An ultrastructural study of the petiolar phloem revealed that the phloem parenchyma and companion cells could be easily distinguished on the basis of the structure of the chloroplasts, dictyosomes, and endoplasmic reticulum. Microfilament bundles and spine-coated tubules and (or) vesicles were uniquely present in the parenchyma cells. The ultrastructure of the phloem parenchyma cells is discussed relative to their possible role in mediating the movement of sugars through the anastomoses.

scholarly journals Control of the acute phase response. Demonstration of C-reactive protein synthesis and secretion by hepatocytes during acute inflammation in the rabbit.

1978 ◽  
Vol 148 (2) ◽  
pp. 466-477 ◽  
Author(s):  
I Kushner ◽  
G Feldmann
Keyword(s):  
Endoplasmic Reticulum ◽  
Acute Phase ◽  
Acute Phase Response ◽  
Smooth Endoplasmic Reticulum ◽  
Phase Response ◽  
Cell Of Origin ◽  
C Reactive Protein ◽  
Electron Microscopic ◽  
Reactive Protein ◽  
Microscopic Studies

To determine the cell of origin of C-reactive protein (CRP) and to cast light on the mechanisms leading to the acute phase response, we used an immunoenzymatic technique to visualize this protein in livers from rabbits at intervals after intramuscular injection of turpentine. CRP was detected only in hepatocytes. 8 h after turpentine injection, CRP was demonstrated in occasional periportal hepatocytes. With time, larger numbers of positive cells were detected successively in perilobular, midlobular, and centrilobular areas. On electron microscopy, CRP was detected in rough endoplasmic reticulum (RER), smooth endoplasmic reticulum (SER), and Golgi apparatus (GA). When colchicine was administered to inhibit cellular secretion of CRP, intensity of reaction and number of CRP-containing hepatocytes were substantially greater than without colchicine, but the sequence of intralobular distribution was similar. At peak serum response 38 h after turpentine injection, CRP could be demonstrated in most hepatocytes. Electron microscopic studies showed accumulation of CRP on membranes and lumina of RER, SER, GA, and in cytoplasmic vacuoles. These findings indicate that CRP is produced by progressively increasing numbers of hepatocytes after inflammatory stimulus and suggest that a mediator, acting initially in portal zones, is responsible for recruitment of cells to CRP production.

scholarly journals TO THE ULTRASTRUCTURAL ORGANIZATION OF EPITHELIOCYTES OF EXOCRINE GLANDS

2021 ◽  
Vol 245 (1) ◽  
pp. 108-112
Author(s):  
N.V. Momot ◽  
◽  
Y.A. Kolina ◽  
I.L. Kamliya ◽  
◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Salivary Glands ◽  
Standard Technique ◽  
Ultrastructural Organization ◽  
Exocrine Glands ◽  
Electron Microscopic ◽  
Large White ◽  
Microscopic Studies ◽  
Sexually Mature ◽  
Large White Pig

Pieces of the sublingual multi-duct salivary glands of a domestic sexually mature large white pig were fixed in a 4 % paraform solution in 0.1 M phosphate buffer (pH = 7.4) with addi-tional fixation in a 1 % OsO4 solution, dehydrated in alcohols of increasing concentration. Taking into account the recommendations of G. Gayer, pieces of organs were poured into araldite accord-ing to the standard technique. Contrasting was performed according to Reynolds. In the cytoplasm of the mucocytes of the sublingual multi-duct salivary gland, the agranu-lar endoplasmic reticulum predominates, which gives oxyphilic staining. According to electron microscopic studies of mucous glandulocytes in the acini of the sub-lingual salivary glands of domestic pigs, the secretory vacuoles of the cytoplasm are large, with pro-nounced electron-dense membranes. The content of vacuoles in mucocytes of one acinus is differ-ent.

A Rapidly Sedimenting Fraction of Rat Liver Endoplasmic Reticulum

1973 ◽  
Vol 13 (2) ◽  
pp. 447-459 ◽  
Author(s):  
J. A. LEWIS ◽  
J. R. TATA
Keyword(s):  
Endoplasmic Reticulum ◽  
Rat Liver ◽  
Microsomal Fraction ◽  
Close Association ◽  
Balance Sheet ◽  
Subcellular Fractionation ◽  
Electron Microscopic ◽  
Microsomal Preparation ◽  
Low Speed ◽  
Microscopic Studies

Balance-sheet experiments carried out to account for the distribution of endoplasmic reticulum fragments during subcellular fractionation of rat liver showed that a large proportion of these fragments are present in the pellets of low-speed centrifugation. Using glucose-6-phosphatase and RNA as markers we found that approximately 50% of the fragments of endoplasmic reticulum sedimented in the pellet of a 640-g centrifugation, 10% in that of a 6000-g centrifugation and 35% in the pellet of a 105000-g centrifugation. Starvation of the animals before use did not alter this distribution, nor did the use of more vigorous homogenization conditions. We have developed a procedure for removing nuclei and erythrocytes from the material sedimenting at 640g to give a fraction (rapidly sedimenting ER fraction or RS-ER) similar to the standard microsomal preparation. Centrifugation of this RS-ER fraction over 1.3 M sucrose yields subfractions of high and low RNA content analogous to the rough and smooth microsomal fractions. Electron-microscopic studies showed that, whereas the rough microsomal fraction consisted of ribosome-studded vesicles of varying size and content density, the rough RS-ER fraction contained a mixture of mitochondria and double lamellar membranes with ribosomes attached. These double lamellar membranes closely resemble the endoplasmic reticulum of intact rat liver. The double lamellar membranes are frequently observed grouped in stacks and in close association with the mitochondria. The significance of the association between endoplasmic reticulum and mitochondria of the RS-ER fraction and the relation between it and the standard microsomal preparation are discussed.

Sign in / Sign up

Export Citation Format

Share Document