The primary action of lithium chloride on morphogenesis in Lymnaea stagnalis

Development ◽  
1969 ◽  
Vol 22 (3) ◽  
pp. 449-463
Author(s):  
P. F. Elbers
Keyword(s):  
Electron Microscopy ◽  
Lithium Chloride ◽  
Lymnaea Stagnalis ◽  
Sea Urchins ◽  
Cortical Layer ◽  
Lithium Ions ◽  
Cytoplasmic Structure ◽  
Electrostatic Effect ◽  
Primary Action

In Lymnaea stagnalis, as in sea urchins, lithium ions cause disturbances of development, notably exogastrulation and head malformations (Raven, 1942). As the effect of a Li-treatment presents itself only after several hours or days of development, the question was raised of the site and the nature of the primary action of the ion in the egg cells, even though it had never been proved that Li actually enters the cells. The Li effect was described as a coarsening of cytoplasmic structure (Runnström, 1928), a condensation of the cytoplasm, caused by dehydration of certain of its colloidal components (Raven & Roborgh, 1949; Raven & van Zeist, 1950), and as an electrostatic effect on phosphatides located in the cortical layer of the egg (Raven, 1956). The controversy between these hypotheses was the original incentive to study this problem by electron microscopy.

Fate of sperm membrane in fertilized ova

1993 ◽  
Vol 51 ◽  
pp. 40-41
Author(s):  
Frank J. Longo
Keyword(s):  
Electron Microscopy ◽  
Electrical Activity ◽  
Sea Urchins ◽  
Morphological Changes ◽  
Integrated System ◽  
Electrophysiological Recording ◽  
Experimental Conditions ◽  
The Status ◽  
Sperm Membrane ◽  
Temporal And Spatial

Measurement of the egg's electrical activity, the fertilization potential or the activation current (in voltage clamped eggs), provides a means of detecting the earliest perceivable response of the egg to the fertilizing sperm. By using the electrical physiological record as a “real time” indicator of the instant of electrical continuity between the gametes, eggs can be inseminated with sperm at lower, more physiological densities, thereby assuring that only one sperm interacts with the egg. Integrating techniques of intracellular electrophysiological recording, video-imaging, and electron microscopy, we are able to identify the fertilizing sperm precisely and correlate the status of gamete organelles with the first indication (fertilization potential/activation current) of the egg's response to the attached sperm. Hence, this integrated system provides improved temporal and spatial resolution of morphological changes at the site of gamete interaction, under a variety of experimental conditions. Using these integrated techniques, we have investigated when sperm-egg plasma membrane fusion occurs in sea urchins with respect to the onset of the egg's change in electrical activity.

scholarly journals Analysis of the type material of Gomphosphenia tackei (Bacillariophyceae) and comparison to epizoic diatom populations on freshwater snails

2021 ◽  
Vol 154 (2) ◽  
pp. 257-263
Author(s):  
Mateusz Rybak ◽  
Łukasz Peszek ◽  
Anita Poradowska
Keyword(s):  
Electron Microscopy ◽  
Lymnaea Stagnalis ◽  
Morphological Characteristics ◽  
Small Cell ◽  
Type Material ◽  
Freshwater Snails ◽  
Sem Images ◽  
Small Cell Size ◽  
Type Population ◽  
Scanning Electron

Background and aims – Hustedt (1942) originally described Gomphosphenia tackei from Germany under the name Gomphonema tackei. Because of the small cell size and the lack of scanning electron microscopy (SEM) images from the type material, it is often confused with other species from this genus, especially with G. stoermeri. The aim of this paper was to present detailed morphological characteristics of G. tackei based on the analysis of the type material and of several epizoic populations from Central Europe. Material and methods – The material in this study was collected from the shells of the freshwater snails Lymnaea stagnalis, Planorbarius corneus, and Planorbis planorbis. Additionally, for an unambiguous species identification, the type material for Gomphosphenia tackei was analyzed using light and scanning electron microscopes.Key results – The presence of Gomphosphenia tackei was confirmed in the studied material. The largest population (up to 19%) was recorded on the shell surfaces of living snails, whereas on empty shells, the diatom did not seem to be present or only in very low numbers. Valves are typically clavate with rounded apices. Valves are frequently observed in girdle view, often joint together in pairs. The valves in the studied populations had a valve length of 7–29 µm, a valve width of 3–4 µm, and a stria density of 25–29 striae in 10 µm. In the type population, valve length ranged from 7.5 to 27 µm with a valve width of 3.0–4.0 µm and a stria density of 23–29 striae per 10 µm. Striae were composed of 2–4 elongated to rounded areolae per stria. At the apices, the striae were composed of one single areola. The cells were attached to the substratum by their footpole.Conclusion – Published illustrations of Gomphosphenia tackei do not always correctly represent this species. Individual cells are attached to the substratum by secreted mucilage, probably via their areolae or girdle band pores located on the footpole.

Inhibition of Glyceraldehyde Phosphate Dehydrogenase by Salts other than Lithium Chloride

Development ◽  
1956 ◽  
Vol 4 (1) ◽  
pp. 93-95
Author(s):  
Richard G. Ham ◽  
Robert E. Eakin
Keyword(s):  
Sodium Chloride ◽  
Lithium Chloride ◽  
Specific Effect ◽  
Lithium Ion ◽  
Developmental Changes ◽  
Lithium Ions ◽  
Sodium Salts ◽  
Glyceraldehyde Phosphate Dehydrogenase ◽  
Typical Data ◽  
Enzyme Study

Lallier (1954) has shown that 0·4 M lithium chloride strongly inactivates glyceraldehyde phosphate dehydrogenase—a finding which might partially explain some of the developmental changes found in lithium-treated embryos. In an attempt to establish an enzymatic basis for the morphological effects of lithium ion on Hydra which have been observed in this laboratory (Ham & Eakin, 1955), we have repeated the enzyme study with lithium chloride and extended it to include a number of other salts as controls. From typical data (Table 1), it is obvious that the inhibition of glyceraldehyde phosphate dehydrogenase activity is in no way a specific effect due to lithium ions. Both sodium chloride and potassium chloride produced a greater inhibition than did lithium chloride. From the various sodium salts tested, it was found that the anion may be of more importance than the cation in determining the degree of inhibition, although the cation also has some effect.

scholarly journals ELECTRON MICROSCOPY OF PLASMA-CELL TUMORS OF THE MOUSE

1961 ◽  
Vol 9 (2) ◽  
pp. 353-368 ◽  
Author(s):  
D. F. Parsons ◽  
E. B. Darden ◽  
D. L. Lindsley ◽  
Guthrie T. Pratt
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Plasma Cell ◽  
Electron Microscope Study ◽  
Plasma Cells ◽  
Granular Body ◽  
Virus Particles ◽  
Cytoplasmic Structure ◽  
Large Numbers ◽  
C3h Mice

An electron microscope study was made of a series of transplanted MPC-1 plasma-cell tumors carried by BALB/c mice. Large numbers of particles similar in morphology to virus particles were present inside the endoplasmic reticulum of tumor plasma cells. Very few particles were seen outside the cells or in ultracentrifuged preparations of the plasma or ascites fluid. In very early tumors particles were occasionally seen free in the cytoplasm adjacent to finely granular material. In general, the distribution of these particles inside endoplasmic reticulum is similar in early and late tumors. A few transplanted X5563 tumors of C3H mice were also examined. Large numbers of particles were found in the region of the Golgi apparatus in late X5663 tumors. A newly described cytoplasmic structure of plasma cells, here called a "granular body," appears to be associated with the formation of the particles. Particles present in MPC-1 tumors are exclusively of a doughnut form, whereas some of those in the inclusions of the late X5563 tumors show a dense center. Normal plasma cells, produced by inoculation of a modified Freund adjuvant into BALB/c mice. have been compared morphologically with tumor plasma cells of both tumor lines.

scholarly journals Demonstration of a Cytoplasmic Structure in Plasma Cells

Blood ◽  
1953 ◽  
Vol 8 (10) ◽  
pp. 916-922 ◽  
Author(s):  
H. BRAUNSTEINER ◽  
K. FELLINGER ◽  
F. PAKESCH
Keyword(s):  
Electron Microscopy ◽  
Bone Marrow ◽  
Plasma Cells ◽  
Filamentous Structure ◽  
Cytoplasmic Structure

Abstract In normal and pathologic plasma cells of the bone marrow, a specific filamentous structure of the cytoplasm has been revealed by electron microscopy. The significance of this structure is briefly discussed.

Cellular analyses of sea urchin metamorphosis

Zygote ◽  
1999 ◽  
Vol 8 (S1) ◽  
pp. S77-S78
Author(s):  
Yukiko Sato ◽  
Ikuko Yazaki
Keyword(s):  
Electron Microscopy ◽  
Fatty Acids ◽  
Squamous Epithelium ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Chromatin Condensation ◽  
Environmental Cues ◽  
Nuclear Chromatin ◽  
Intracellular Changes ◽  
Hemicentrotus Pulcherrimus

Larvae of marine invertebrates undergo metamorphosis in response to environmental cues (Chia & Burke, 1978). In sea urchins, free fatty acids (Kitamura et al., 1993), dibromomethane (Taniguchi et al., 1994), pheromonal peptides (Burke, 1984) and L-glutamine (Yazaki & Harashima, 1994; Yazaki, 1995) have been known as metamorphosis-inducing substances. The mechanisms by which cells respond to these cues and how the larval tissues are absorbed have not been clear, however. In the present study, we used L-glutamine (Gln) and a natural cue, green algae (Ulvella sp.), to induce metamorphosis of Hemicentrotus pulcherrimus and Anthocidaris crassispina, and investigated the intracellular changes during metamorphosis.After being subjected to 10−5–10−3 M Gln for 10–24 h, larvae cease swimming, settle, begin to retract their larval arms, extrude the primary podia and finally evert their echinus rudiment (ER). In H. pulcherrimus, larvae retracted their arms from 6 h to 24 h after the start of Gln treatment and then everted the ER. A. crassispina larvae underwent similar processes to those of H. pulcherrimus. The larval surface is composed of squamous epithelium and columnar epithelium. The epithelium of the ciliary bands or epaulets is columnar.In the squamous epithelium, the nuclear chromatin in the larval arms and body, and in the oesophagus, markedly condensed after treatment with Gln for 24 h. Electron microscopy revealed swelling of both nuclei and mitochondria, while their membranes seemed to be intact. In the cytoplasm, lipid-like structures and electron-dense substances appeared. A further 24 h after Gln treatment, the chromatin condensation had progressed. Most nuclei in which chromatin had condensed were positive to the TUNEL assay, which detects DNA fragmentation. These results suggest that cell death in the squamous epithelium is apoptotic rather than necrotic.

Hvem and Internal Oxidation Studies of Lithiated Nickel

1983 ◽  
Vol 27 ◽  
Author(s):  
K. Seshan ◽  
P. Baldo ◽  
H. Wiedersich
Keyword(s):  
Electron Microscopy ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Pure Nickel ◽  
High Dose ◽  
Polycrystalline Nickel ◽  
Lithium Ions ◽  
Helium Bubbles ◽  
Implantation Damage ◽  
The Difference

ABSTRACTPure, polycrystalline nickel samples were implanted with lithium to doses up to 5 × 1017 lithium ions per square centimeter, at a temperature of 500°C, such that the implantation damage would anneal. These samples were then prepared for electron microscopy and examined at 1 MeV, in the Argonne National Laboratory HVEM facility. It was observed that compared to pure nickel, the lithium implanted nickel showed a different radiation damage behaviour. A plausible explanation for the difference in behaviour is presented in this paper.The lithium implanted nickel, in the high dose samples, also showed an unusual form of precipitation. Electron microscopy revealed the precipitates to have truncated octahedral shapes with {111} planes for sides and {100} planes truncating the corners. They resemble voids and helium bubbles in nickel. The precipitates appear to be associated with dislocations. The lithium implanted nickel was internally oxidized in order to obtain evidence for the presence of lithium. Electron diffraction analysis of the internally oxidized lithiated nickel showed the presence of a topo-taxial compound being formed, with an ordered NaCl-structure. Possible interpretations of this diffraction pattern are discussed.

scholarly journals THE ACTION OF EXCESS OF VITAMIN A ALCOHOL ON THE FINE STRUCTURE OF RAT DERMAL FIBROBLASTS

1966 ◽  
Vol 30 (3) ◽  
pp. 465-475 ◽  
Author(s):  
Mary R. Daniel ◽  
J. T. Dingle ◽  
Audrey M. Glauert ◽  
J. A. Lucy
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Vitamin A ◽  
Respiratory Activity ◽  
Dermal Fibroblasts ◽  
Rapid Decline ◽  
Primary Action ◽  
Membranous Material

Rat dermal fibroblasts were grown as monolayers, and changes in the fine structure of the cells that occurred during 12 hr incubation in a medium containing protein and excess of retinol (vitamin A alcohol) were studied by electron microscopy. There is little change during the first 6 hr, although some of the nuclei have highly convoluted membranes. During the subsequent 3 hr, there is some disorganization of the mitochondrial cristae; the cisternae of the rough-surfaced endoplasmic reticulum diminish in number; and the amount of smooth membranous material and free ribosomes increases. There is a rapid decline in the respiratory activity of the cells after 6 hr exposure to the vitamin. It is concluded that the primary action of excess of retinol is to cause alterations in the membranes of the cells and that these alterations affect the functions of the mitochondria and endoplasmic reticulum.

scholarly journals Novel Functionality of Lithium-Impregnated Titania as Nanocatalyst

Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 943
Author(s):  
Indu Ambat ◽  
Varsha Srivastava ◽  
Esa Haapaniemi ◽  
Mika Sillanpää
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
Acid Methyl Ester ◽  
Optical Emission ◽  
Waste Cooking Oil ◽  
Catalytic Performance ◽  
Physical Parameters ◽  
Lithium Ions ◽  
13C Nuclear Magnetic Resonance ◽  
Bet Analysis

The present work incorporates the synthesis of a multifunctional catalyst for the transesterification of waste cooking oil (WCO) to biodiesel and recovery of rare earth elements (REEs). For this purpose, TiO2 nanoparticles and TiO2 doped with lithium ions were prepared. The influence of lithium ions on the catalytic performance of TiO2 was attained by impregnation of the different molar ratios of lithium hydroxide to bare TiO2. Then each catalyst was screened for catalytic conversion of WCO to fatty acid methyl ester (FAME) and also for REEs recovery. All synthesized materials were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) analysis, and Hammett indicator for the basicity test. The obtained biodiesel was characterized by gas chromatography with mass spectrometry (GC-MS), 1H, and 13C nuclear magnetic resonance (NMR). Moreover, the physical parameters of the synthesized biodiesel were also determined. The REEs recovery efficiency of synthesized nanomaterials was investigated, and the percentage of REEs removal was determined by inductively-coupled plasma optical emission spectroscopy (ICP-OES).

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