scholarly journals SPHEROIDAL AND RING NUCLEOLI IN AMPHIBIAN OOCYTES

1967 ◽  
Vol 35 (2) ◽  
pp. 421-434 ◽  
Author(s):  
Nancy J. Lane
Keyword(s):  
Granular Material ◽  
Rna Synthesis ◽  
Morphological Changes ◽  
Ambystoma Mexicanum ◽  
Entire Length ◽  
Short Term ◽  
Asymmetrical Pattern ◽  
Fibrillar Component

In maturing oocytes of the newt Triturus viridescens, the nucleoli undergo a series of morphological changes that are very similar to those described by Callan for the axolotl, Ambystoma mexicanum. The nucleoli first assume the form of spheroids which then become extended into ring or necklace shapes that are DNase-sensitive; in mature oocytes the nucleoli revert to a spheroidal form. Short term in vitro incorporation studies with uridine-3H on both species show that RNA synthesis occurs in a restricted, eccentric portion of the spheroidal nucleoli, thereby producing an asymmetrical pattern of labeling. In the ring forms, however, the localization of the radioactivity suggests that synthesis takes place symmetrically throughout their entire length. The changes in nucleolar morphology apparently reflect the fact that the component DNA has undergone a redistribution from a localized region in the spheroidal nucleoli to an extended circle in the rings; the patterns of uridine-3H incorporation, therefore, parallel the distribution of DNA in both the spheroidal and the ring nucleoli. Ultrastructurally, the nucleoli contain a fibrillar component that corresponds in position to that of the DNA. The typical spheroidal nucleolus consists of a fibrillar core situated eccentrically and surrounded by a hull of granular, ribonucleoprotein material. The ring nucleoli are composed of a central fibrous region that is ensheathed all around its circumference by a layer of similar granular material. This granular substance is thicker at intervals along the length of the rings, representing the "beads" of the necklaces.

scholarly journals The Model of D-Galactosamine-Induced Injury of Rat Hepatocytes in Primary Culture

2006 ◽  
Vol 49 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Otto Kučera ◽  
Halka Lotková ◽  
Roman Kanďár ◽  
Renata Héžová ◽  
Vladimíra Mužáková ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Animal Experiments ◽  
Rat Hepatocytes ◽  
Short Term ◽  
Hepatocyte Injury ◽  
Albumin Production ◽  
Potential Activity ◽  
Dose Dependent ◽  
Uridine Nucleotides

D-galactosamine (GalN) is a highly selective hepatotoxin that causes liver damage similar to human viral hepatitis via depletion of uridine nucleotides, which subsequently diminishes synthesis of RNA and proteins. Model of galactosamine hepatotoxicity is frequently used in animal experiments in vitro. The purpose of our study was to establish the model of GalN-induced hepatocyte injury in in vitro conditions using primocultures of rat hepatocytes as an important prerequisite for further experiments in which we would like to study potential hepatoprotective effect of various substances. Rate of hepatocyte injury was evaluated by morphological changes, changes in cell viability, albumin production, mitochondrial membrane potential, activity of mitochondrial dehydrogenases and glutathione content. Marked dose dependent hepatocyte injury was found after 24-hour incubation with GalN. Based on the results we suggest as an optimal model for short-term toxicity test exposure to GalN for 24 hours in dose of 40 mM.

Effects of erythropoietin on cell populations and macromolecular syntheses in foetal mouse erythroid cells

Development ◽  
1973 ◽  
Vol 29 (2) ◽  
pp. 453-472
Author(s):  
John Paul ◽  
David Conkie ◽  
Hugo Burgos
Keyword(s):  
Dna Synthesis ◽  
Mouse Liver ◽  
Rna Synthesis ◽  
Normal Development ◽  
Cell Populations ◽  
Erythroid Cells ◽  
Short Term ◽  
Cell Compartments ◽  
Normal Series

The effects of erythropoietin on maturation of erythroid cells were studied in short-term cultures of foetal mouse liver. Erythropoietin-treated cultures had about 50% more cells than untreated cultures after 24 h. The increase occurred in basophilic, polychromatic and orthochromatic erythroblasts as well as in reticulocytes. A striking feature of erythropoietin-treated cultures was the formation of macro-erythroblasts and macrocytes. Autoradiographic studies indicated that a maturation division was omitted in the formation of these cells and that macrocytes might be derived directly from polychromatic erythroblasts or earlier stages. These studies also indicated that there might be no more than three divisions during the normal development of orthochromatic erythroblasts from proerythroblasts in vitro. The mitotic index of proerythroblasts was raised in erythropoietin-treated cultures within 1–2 h. Moreover, erythropoietin caused a marked elevation of DNA synthesis in proerythroblasts within the first hour of culture but effects on DNA synthesis in other cell compartments were not pronounced. In contrast, an increase in RNA synthesis was noted in proerythroblasts and basophilic and polychromatic erythroblasts; it was greatest in the two former compartments. The stimulation was noticeable, especially in the basophilic compartment, within 2 h but increased progressively throughout the first 5–6 h. Erythropoietin did not induce an increase in total protein synthesis in cells of the normal series but macro-erythroblasts exhibited proportionately more grains.

scholarly journals Behaviour and neuropathology in mice injected with human contactin-associated protein 2 antibodies

Brain ◽  
2019 ◽  
Vol 142 (7) ◽  
pp. 2000-2012 ◽  
Author(s):  
Maria Pia Giannoccaro ◽  
David A Menassa ◽  
Leslie Jacobson ◽  
Ester Coutinho ◽  
Gennaro Prota ◽  
...  
Keyword(s):  
Working Memory ◽  
Social Interactions ◽  
Hippocampal Neurons ◽  
Morphological Changes ◽  
Brain Regions ◽  
Complement C3 ◽  
Short Term ◽  
Wide Range ◽  
Fos Expression

Abstract Serum antibodies that bind to the surface of neurons or glia are associated with a wide range of rare but treatable CNS diseases. In many, if not most instances, the serum levels are higher than CSF levels yet most of the reported attempts to reproduce the human disease in mice have used infusion of antibodies into the mouse cerebral ventricle(s) or intrathecal space. We used the intraperitoneal route and injected purified plasma IgG from either a CASPR2-antibody-positive patient (n = 10 mice) or healthy individual (n = 9 mice) daily for 8 days. Lipopolysaccharide was injected intraperitoneally on Day 3 to cause a temporary breach in the blood brain barrier. A wide range of baseline behaviours, including tests of locomotion, coordination, memory, anxiety and social interactions, were established before the injections and tested from Day 5 until Day 11. At termination, brain tissue was analysed for human IgG, CASPR2 and c-fos expression, lymphocyte infiltration, and neuronal, astrocytic and microglial markers. Mice exposed to CASPR2-IgG, compared with control-IgG injected mice, displayed reduced working memory during the continuous spontaneous alternation test with trends towards reduced short-term and long-term memories. In the open field tests, activities were not different from controls, but in the reciprocal social interaction test, CASPR2-IgG injected mice showed longer latency to start interacting, associated with more freezing behaviour and reduced non-social activities of rearing and grooming. At termination, neuropathology showed more IgG deposited in the brains of CASPR2-IgG injected mice, but a trend towards increased CASPR2 expression; these results were mirrored in short-term in vitro experiments where CASPR2-IgG binding to hippocampal neurons and to CASPR2-transfected HEK cells led to some internalization of the IgG, but with a trend towards higher surface CASPR2 expression. Despite these limited results, in the CASPR2-IgG injected mouse brains there was increased c-fos expression in the piriform-entorhinal cortex and hypothalamus, and a modest loss of Purkinje cells. There was also increased microglia density, morphological changes in both microglia and astrocytes and raised complement C3 expression on astrocytes, all consistent with glial activation. Patients with CASPR2 antibodies can present with a range of clinical features reflecting central, autonomic and peripheral dysfunction. Although the behavioural changes in mice were limited to social interactions and mild working-memory defects, the neuropathological features indicate potentially widespread effects of the antibodies on different brain regions.

Nature of the So-Called Fibrillar Component in the Segregated Nucleolus

1972 ◽  
Vol 30 ◽  
pp. 244-245
Author(s):  
T. Unuma ◽  
R. Senda ◽  
M. Muramatsu
Keyword(s):  
Rna Synthesis ◽  
Actinomycin D ◽  
Morphological Changes ◽  
Enzymatic Digestion ◽  
The Other ◽  
Granular Component ◽  
Fibrillar Component ◽  
Nucleolar Segregation ◽  
Nucleolar Components

Actinomycin D, selectively blocks DNA-dependent RNA synthesis, causes marked morphological changes of the nucleolus. One of the most prominent changes is the segregation of the nucleolar components. The granular component is redistributed and separated from the other components of the nucleolus. The term nucleolar segregation has been used to designate the separation of the granular and fibrillar components. In the present study, the nucleolus was segregated into two distinct zones, namely the granular and the so-called fibrillar component (Fig. 1). The purpose of this study is to present the evidences of protelnous nature of the so-called fibrillar component in the segregated nucleolus by morphological, biochemical and enzymatic digestion studies.

scholarly journals Effect of Surface Digestion and Metabolic Inhibitors on Appearance of Ferritin in Guinea Pig Erythroblasts In Vitro: Evidences for the Production of Apoferritin on the Erythroblast Cell Membrane

Blood ◽  
1971 ◽  
Vol 37 (2) ◽  
pp. 211-219 ◽  
Author(s):  
YASUKAZU TANAKA ◽  
GEORGE BRECHER
Keyword(s):  
Cell Surface ◽  
Guinea Pig ◽  
Rna Synthesis ◽  
Lead Nitrate ◽  
Potassium Cyanide ◽  
Metabolic Inhibitors ◽  
Short Term ◽  
Normal Transport ◽  
Effect Of Surface

Abstract Short-term cultures of guinea pig erythroblasts permitted observation on the micropinocytosis (rhopheocytosis) of ferritin. In the presence of enzymes that attack the cell surface (neuraminidase and trypsin) or of an inhibitor of RNA synthesis (puromycin), accumulation of ferritin in the micropinocytotic vesicle was reduced. No change was seen in presence of lead nitrate, which inhibits transport of iron into hemoglobin-synthesizing cells only slightly. In the presence of potassium cyanide, which inhibits iron transport markedly, ferritin increased two-seven times over controls. The data are compatible with the notion that apoferritin is made on or near the cell surface in response to an excess of iron which accumulates on the cell surface due to failure or overloading of the normal transport mechanism.

Effect of Some Metabolic Inhibitors on Vinblastine-Induced Ribosomal-Granular Material Complexes

1971 ◽  
Vol 29 ◽  
pp. 548-549
Author(s):  
Awtar Krishan ◽  
Dora Hsu
Keyword(s):  
Granular Material ◽  
Rna Synthesis ◽  
Culture Medium ◽  
Actinomycin D ◽  
Metabolic Inhibitors ◽  
Protein And Rna Synthesis ◽  
Apparent Reduction ◽  
Plant Alkaloids ◽  
In Cells

Cells exposed to antitumor plant alkaloids, vinblastine and vincristine sulfate have large proteinacious crystals and complexes of ribosomes, helical polyribosomes and electron-dense granular material (ribosomal complexes) in their cytoplasm, Binding of H3-colchicine by the in vivo crystals shows that they contain microtubular proteins. Association of ribosomal complexes with the crystals suggests that these structures may be interrelated.In the present study cultured human leukemic lymphoblasts (CCRF-CEM), were incubated with protein and RNA-synthesis inhibitors, p. fluorophenylalanine, puromycin, cycloheximide or actinomycin-D before the addition of crystal-inducing doses of vinblastine to the culture medium. None of these compounds could completely prevent the formation of the ribosomal complexes or the crystals. However, in cells pre-incubated with puromycin, cycloheximide, or actinomycin-D, a reduction in the number and size of the ribosomal complexes was seen. Large helical polyribosomes were absent in the ribosomal complexes of cells treated with puromycin, while in cells exposed to cycloheximide, there was an apparent reduction in the number of ribosomes associated with the ribosomal complexes (Fig. 2).

Correlation Between Cellular Functions and Morphological Changes of Human Trophoblast in Vitro

1975 ◽  
Vol 33 ◽  
pp. 600-601
Author(s):  
John C. Garancis ◽  
Robert O. Hussa ◽  
Michael T. Story ◽  
Donald Yorde ◽  
Roland A. Pattillo
Keyword(s):  
Electron Microscopy ◽  
Cellular Proliferation ◽  
Morphological Changes ◽  
Culture Fluid ◽  
Cellular Functions ◽  
Human Trophoblast ◽  
Transmission Electron ◽  
Marked Activity ◽  
Malignant Trophoblast

Human malignant trophoblast cells in continuous culture were incubated for 3 days in medium containing 1 mM N6-O2'-dibutyryl cyclic adenosine 3':5'-monophosphate (dibutyryl cyclic AMP) and 1 mM theophylline. The culture fluid was replenished daily. Stimulated cultures secreted many times more chorionic gonadotropin and estrogens than did control cultures in the absence of increased cellular proliferation. Scanning electron microscopy revealed remarkable surface changes of stimulated cells. Control cells (not stimulated) were smooth or provided with varying numbers of microvilli (Fig. 1). The latter, usually, were short and thin. The surface features of stimulated cells were considerably different. There was marked increase of microvilli which appeared elongated and thick. Many cells were covered with confluent polypoid projections (Fig. 2). Transmission electron microscopy demonstrated marked activity of cytoplasmic organelles. Mitochondria were increased in number and size; some giant forms with numerous cristae were observed.

Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

1990 ◽  
Vol 48 (3) ◽  
pp. 374-375
Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson
Keyword(s):  
Antidepressant Drug ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Short Term ◽  
Platelet Counts ◽  
Toxicological Studies ◽  
Induced Aggregation ◽  
Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

Morphological Changes in the Brain of Acutely Ill and Weight-Recovered Patients with Anorexia Nervosa

2014 ◽  
Vol 42 (1) ◽  
pp. 7-18 ◽  
Author(s):  
Jochen Seitz ◽  
Katharina Bühren ◽  
Georg G. von Polier ◽  
Nicole Heussen ◽  
Beate Herpertz-Dahlmann ◽  
...  
Keyword(s):  
Anorexia Nervosa ◽  
Cognitive Deficits ◽  
Time Course ◽  
Morphological Changes ◽  
Meta Analysis ◽  
Short Term ◽  
Clinical Prognosis ◽  
Qualitative Review ◽  
Brain Changes ◽  
The Brain

Objective: Acute anorexia nervosa (AN) leads to reduced gray (GM) and white matter (WM) volume in the brain, which however improves again upon restoration of weight. Yet little is known about the extent and clinical correlates of these brain changes, nor do we know much about the time-course and completeness of their recovery. Methods: We conducted a meta-analysis and a qualitative review of all magnetic resonance imaging studies involving volume analyses of the brain in both acute and recovered AN. Results: We identified structural neuroimaging studies with a total of 214 acute AN patients and 177 weight-recovered AN patients. In acute AN, GM was reduced by 5.6% and WM by 3.8% compared to healthy controls (HC). Short-term weight recovery 2–5 months after admission resulted in restitution of about half of the GM aberrations and almost full WM recovery. After 2–8 years of remission GM and WM were nearly normalized, and differences to HC (GM: –1.0%, WM: –0.7%) were no longer significant, although small residual changes could not be ruled out. In the qualitative review some studies found GM volume loss to be associated with cognitive deficits and clinical prognosis. Conclusions: GM and WM were strongly reduced in acute AN. The completeness of brain volume rehabilitation remained equivocal.

The Effect of Dimethyl Sulfoxide on In Vitro Platelet Function

1976 ◽  
Vol 36 (01) ◽  
pp. 221-229 ◽  
Author(s):  
Charles A. Schiffer ◽  
Caroline L. Whitaker ◽  
Morton Schmukler ◽  
Joseph Aisner ◽  
Steven L. Hilbert
Keyword(s):  
Platelet Count ◽  
Platelet Aggregation ◽  
Dimethyl Sulfoxide ◽  
Platelet Function ◽  
Platelet Volume ◽  
Short Term ◽  
Platelet Factor ◽  
Short Term Exposure ◽  
Structural Abnormalities

SummaryAlthough dimethyl sulfoxide (DMSO) has been used extensively as a cryopreservative for platelets there are few studies dealing with the effect of DMSO on platelet function. Using techniques similar to those employed in platelet cryopreservation platelets were incubated with final concentrations of 2-10% DMSO at 25° C. After exposure to 5 and 10% DMSO platelets remained discoid and electron micrographs revealed no structural abnormalities. There was no significant change in platelet count. In terms of injury to platelet membranes, there was no increased availability of platelet factor-3 or leakage of nucleotides, 5 hydroxytryptamine (5HT) or glycosidases with final DMSO concentrations of 2.5, 5 and 10% DMSO. Thrombin stimulated nucleotide and 5HT release was reduced by 10% DMSO. Impairment of thrombin induced glycosidase release was noted at lower DMSO concentrations and was dose related. Similarly, aggregation to ADP was progressively impaired at DMSO concentrations from 1-5% and was dose related. After the platelets exposed to DMSO were washed, however, aggregation and release returned to control values. Platelet aggregation by epinephrine was also inhibited by DMSO and this could not be corrected by washing the platelets. DMSO-plasma solutions are hypertonic but only minimal increases in platelet volume (at 10% DMSO) could be detected. Shrinkage of platelets was seen with hypertonic solutions of sodium chloride or sucrose suggesting that the rapid transmembrane passage of DMSO prevented significant shifts of water. These studies demonstrate that there are minimal irreversible alterations in in vitro platelet function after short-term exposure to DMSO.

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