Changes in Electrical Connection During Cell Fusion in the Heliozoan, Echinosphaerium Akamae

1988 ◽  
Vol 135 (1) ◽  
pp. 183-191
Author(s):  
TAKAKO NISHI ◽  
TSUKASA GOTOW ◽  
MAKOTO KOBAYASHI
Keyword(s):  
Membrane Fusion ◽  
Cell Fusion ◽  
Cell Body ◽  
Intracellular Recording ◽  
Early Stage ◽  
The Other ◽  
Electrical Connection ◽  
Advanced Stages ◽  
Unicellular Organisms ◽  
Paired Cell

The electrophysiology of cell fusion in the heliozoan, Echinosphaetium akamae, was studied by intracellular recording from two unicellular organisms undergoing fusion. Fusion was preceded by the electrical connection of axopodia of each cell to the cell body of the other. In the early stages of the fusion process, spikes evoked in one cell body failed to invade the other, but electrotonic potentials (subthreshold depolarizations) did pass to the other cell. When background depolarizing currents were injected into the organism into which the potentials had invaded, these potentials developed into spikes. In advanced stages of fusion, spikes were transmitted in both directions from one organism to the other, in the absence of polarizing current. At this time, application of appropriate hyperpolarizing currents to either of the two organisms prevented spikes produced in one from invading the other. These results suggest that in the early stage of fusion, relatively few axopodia were bridged by membrane fusion between paired cell bodies, and that the number of such bridged axopodia increased as fusion proceeded, allowing spikes to be transmitted between the two organisms.

scholarly journals Reorganization of cytoplasmic structures during cell fusion

1991 ◽  
Vol 100 (3) ◽  
pp. 431-442 ◽  
Author(s):  
Q.A. Zheng ◽  
D.C. Chang
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Fusion ◽  
Intermediate Filaments ◽  
Early Stage ◽  
Cytoskeletal Proteins ◽  
The Other ◽  
Primary Role ◽  
Cytoplasmic Bridges ◽  
Cytoskeletal Networks ◽  
Cytoplasmic Structures

In order to provide a better understanding of the dynamic process of cell fusion, we studied the reorganization of cytoplasmic structures in electro-fused CV-1 cells. Using fluorescence microscopy and double staining methods, we examined correlations between the structural patterns of the major cytoskeletal proteins (microtubules, actin and vimentin intermediate filaments) and the distribution of various organelles (endoplasmic reticulum, mitochondria and nuclei) at different stages of cell fusion. Our results suggest that microtubules appear to play a primary role in the process of cytoplasmic reorganization. At the early stage of cell fusion, microtubules were observed to infiltrate rapidly into the newly formed cytoplasmic bridges and establish a connection between the cytoskeletal networks of fusing cells. The reorganization of microtubules was found to be correlated with the redistribution of endoplasmic reticulum (ER), vimentin intermediate filaments, mitochondria, and the aggregation of nuclei. The F-actin system, on the other hand, appeared to be independent of the reorganization of the other cytoplasmic structures. The principal function of F-actin during cell fusion is probably to widen the cytoplasmic bridges by lamellipodial extension.

LRIG1 and squamous epithelial uterine cervical cancer: correlation to prognosis, other tumor markers, sex steroid hormones, and smoking

2008 ◽  
Vol 18 (2) ◽  
pp. 312-317 ◽  
Author(s):  
A. K. Lindström ◽  
K. Ekman ◽  
U. Stendahl ◽  
T. Tot ◽  
R. Henriksson ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Tumor Markers ◽  
Early Stage ◽  
Clinical Stage ◽  
High Serum ◽  
The Other ◽  
Smoking History ◽  
Serum Progesterone ◽  
Stage Ib ◽  
Advanced Stages

The aim is to evaluate LRIG1 as a prognosis predictor and correlations to cofactors in squamous cell cervical cancer. LRIG1 expression was studied in 128 cervical carcinomas and was compared with expression of nine other tumor markers. Smoking history was registered and pretreatment serum estradiol and progesterone levels were evaluated in 79 women. At clinical stage IB, 58% of the tumors showed LRIG1 expression, but there was a decline by increasing stage (33% in stage IV). Ninety percent of women with stage IB cancer and LRIG1 positivity survived, as compared to 64% without expression (P= 0.02). LRIG1 expression did not predict prognosis in advanced stages, but in stage IIA there was a marked relative difference, with 75% survival in tumors expressing LRIG1, as compared to 43% in those without. No correlation was found between LRIG1 and the other nine tumor markers studied. A high serum progesterone and smoking correlated to absent LRIG1 expression. We conclude that LRIG1 appears to be a significant prognosis predictor in early-stage cervical cancer, independent of the other tumor markers that were studied. Diminished expression in advanced stages and the inverse correlation to serum progesterone and smoking indicates that LRIG1 is a tumor suppressor in cervix.

scholarly journals An Early Stage of Membrane Fusion Mediated by the Low pH Conformation of Influenza Hemagglutinin Depends upon Membrane Lipids

1997 ◽  
Vol 136 (1) ◽  
pp. 81-93 ◽  
Author(s):  
Leonid V. Chernomordik ◽  
Eugenia Leikina ◽  
Vadim Frolov ◽  
Peter Bronk ◽  
Joshua Zimmerberg
Keyword(s):  
Membrane Fusion ◽  
Lipid Bilayers ◽  
Cell Fusion ◽  
Membrane Lipids ◽  
Early Stage ◽  
Molecular Shape ◽  
Membrane Lipid ◽  
Low Ph ◽  
Fusion Pore ◽  
Influenza Hemagglutinin

While the specificity and timing of membrane fusion in diverse physiological reactions, including virus–cell fusion, is determined by proteins, fusion always involves the merger of membrane lipid bilayers. We have isolated a lipid-dependent stage of cell–cell fusion mediated by influenza hemagglutinin and triggered by cell exposure to mildly acidic pH. This stage preceded actual membrane merger and fusion pore formation but was subsequent to a low pH–induced change in hemagglutinin conformation that is required for fusion. A low pH conformation of hemagglutinin was required to achieve this lipid-dependent stage and also, downstream of it, to drive fusion to completion. The lower the pH of the medium applied to trigger fusion and, thus, the more hemagglutinin molecules activated, the less profound was the dependence of fusion on lipids. Membrane-incorporated lipids affected fusion in a manner that correlated with their dynamic molecular shape, a characteristic that determines a lipid monolayer's propensity to bend in different directions. The lipid sensitivity of this stage, i.e., inhibition of fusion by inverted cone–shaped lysophosphatidylcholine and promotion by cone-shaped oleic acid, was consistent with the stalk hypothesis of fusion, suggesting that fusion proteins begin membrane merger by promoting the formation of a bent, lipid-involving, stalk intermediate.

Interneurones Co-Ordinating the Ventilatory Movements of the Thoracic Spiracles in the Locust

1982 ◽  
Vol 97 (1) ◽  
pp. 385-400
Author(s):  
MALCOLM BURROWS
Keyword(s):  
Cell Body ◽  
Synaptic Input ◽  
Intracellular Recording ◽  
The Other ◽  
Constant Frequency ◽  
Initial Frequency ◽  
Inspiratory Phase ◽  
Metathoracic Ganglion ◽  
Motor Neurones ◽  
The Right

A pair of interneurones has been identified by intracellular recording and staining which co-ordinates the movements of the thoracic spiracles in the ventilatory rhythm. An interneurone has its cell body on the left or on the right side of the metathoracic ganglion and an axon which ascends to the other thoracic ganglia in the contralateral connective. Each interneurone produces bursts of spikes in time with the inspiratory phase of ventilation. These spikes evoke inhibitory post-synaptic potentials (IPSPs) in thoracic spiracular closer motor neurones. Both interneurones synapse upon the closer motor neurones in each thoracic segment. These connexions, which may be direct, inhibit the spiking of the closer motor neurones during inspiration. The interneurones do not appear to have an innate rhythmicity but instead receive a periodic synaptic input which inhibits their spikes during expiration. The underlying cause of the spikes is less clear. Apart from brief periods at the start and end of a burst, the spikes occur at a constant frequency that is independent of the ventilatory rate. The pattern of the spiracular motor output could be altered by manipulating the frequency and number of spikes in an interneurone. When the frequency of spikes in the interneurone was raised, the motor bursts had a higher initial frequency and were of briefer duration; when the frequency was lowered, the motor bursts were of lower initial frequency and of longer overall duration. Altering the spikes in one interneurone, however, could not affect the frequency of the ventilatory rhythm, or reset the rhythm.

Cognitive Functioning and Other Discriminatory Variables in Anorexic Patients

2005 ◽  
Vol 27 (1) ◽  
pp. 191-210 ◽  
Author(s):  
Carmen García-Alba
Keyword(s):  
Cognitive Functioning ◽  
Research Study ◽  
Early Stage ◽  
Developmental Period ◽  
The Other ◽  
Model Synthesis ◽  
Consistent Function ◽  
Current Article ◽  
Rorschach Variables ◽  
Underlying Pathology

This study is part of a larger research study (doctoral dissertation), in which a comparative study with adolescent samples is done: 50 anorexic restricting patients (ANP), 50 patients diagnosed with depression (DP) and 50 non patients (NP). The proposed objective is two-fold: 1) To try to clarify the existing relationship between Anorexia (AN) and Depression (D), investigated from diverse disciplines but without conclusive results. 2) To detect in the ANP personality different traits from those of other groups, which should, if possible, allow to detect them at an early stage for an adequate prognosis. The current article presents the Rorschach findings in relation to the cognitive functioning of the ANP. In them, the following has been detected: (1) An information processing similar to that of the other groups, even with a more complete (L ≤ .99), more complex (DQ+↑) and better discriminated (Zd↑) grasp of the stimulus; (2) Mediating processes very similar to those of the other groups, sharing with them the perceptive maladjustments (X–%↑) and an excessive individualism (Xu%↑); (3) A clearly differentiating ideation disorder. Definitely, the ANP use predominantly ideation (M↑), but their thought, usually well-adjusted (MQo↑), presents eventual operations of delusional type (MQnone↑). Above that, their thinking is marked by a great passivity (Mp↑), which makes them more vulnerable to accept ideas without criticizing them and it results in a very inefficient thinking, which spins around these concepts without finding solutions, entering into a sort of ruminating which is completely unproductive. The differences toward the obsessive pathology are established. The discriminant analysis conducted with all the Rorschach variables that resulted as significant throughout the research, provides quite a consistent function which discriminates the ANP: MQnone↑, Mp↑, FD↓, Ma↑, MQo↑, AdjD↑, Sum H↑, (H)↑. Based on this we can understand that these adolescents, being in a developmental period of big changes and disorientations in relation with their own image, confronted with life events, and possibly starting off with some biologic vulnerability: (1) Due to the alterations of their ideation, accept without criticism (Mp) irrational ideas dominating in our culture, in which slimness appears as the only model, synthesis of intelligence, beauty and success; remaining captured in this type of mental activity (MQnone), which they cannot escape nor criticize (Mp), despite they reason adequately on other topics (MQo); (2) Their alterations of self-perception [(H)] make them hide themselves in a fantasized image, which is the axis of their interests and the only thing that really matters to them; (3) The resources they have to decide on behaviors and to finish these deliberately (AdjD), and their scarce tendency to the introspection (FD) lead to their decision of not eating, based on distorted and passively accepted thinking, which has great power and thus, so difficult to modify. Finally, based on the Rorschach data obtained, the hypothesis of a personality disorder as underlying pathology is pointed out.

The Application of UX Research in New Energy Vehicle Innovation

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Menghan TAO ◽  
Ning XIAO ◽  
Xingfu ZHAO ◽  
Wenbin LIU
Keyword(s):  
Early Stage ◽  
Rapid Expansion ◽  
The Other ◽  
Innovative Product ◽  
Stage Of Development ◽  
New Energy ◽  
New Energy Vehicle ◽  
The One ◽  
New Energy Vehicles ◽  
Degree Of Innovation

New energy vehicles(NEV) as a new thing for sustainable development, in China, on the one hand has faced the rapid expansion of the market; the other hand, for the new NEV users, the current NEVs cannot keep up with the degree of innovation. This paper demonstrates the reasons for the existence of this systematic challenge, and puts forward the method of UX research which is different from the traditional petrol vehicles research in the early stage of development, which studies from the user's essence level, to form the innovative product programs which meet the needs of users and being real attractive.

scholarly journals Relative COVID-19 Viral Persistence and Antibody Kinetics

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 752
Author(s):  
Chung-Guei Huang ◽  
Avijit Dutta ◽  
Ching-Tai Huang ◽  
Pi-Yueh Chang ◽  
Mei-Jen Hsiao ◽  
...  
Keyword(s):  
Early Stage ◽  
Severe Disease ◽  
Serum Antibody ◽  
Viral Persistence ◽  
Viral Clearance ◽  
The Other ◽  
Cytokines And Chemokines ◽  
Virus Clearance ◽  
Antibody Kinetics ◽  
Deceased Patient

A total of 15 RT-PCR confirmed COVID-19 patients were admitted to our hospital during the in-itial outbreak in Taiwan. The average time of virus clearance was delayed in seven patients, 24.14 ± 4.33 days compared to 10.25 ± 0.56 days post-symptom onset (PSO) in the other eight pa-tients. There was strong antibody response in patients with viral persistence at the pharynx, with peak values of serum antibody 677.2 ± 217.8 vs. 76.70 ± 32.11 in patients with delayed versus rapid virus clearance. The patients with delayed viral clearance had excessive antibodies of compromised quality in an early stage with the delay in peak virus neutralization efficacy, 34.14 ± 7.15 versus 12.50 ± 2.35 days PSO in patients with rapid virus clearance. Weak antibody re-sponse of patients with rapid viral clearance was also effective, with substantial and comparable neutralization efficacy, 35.70 ± 8.78 versus 41.37 ± 11.49 of patients with delayed virus clearance. Human Cytokine 48-Plex Screening of the serial sera samples revealed elevated concentrations of proinflammatory cytokines and chemokines in a deceased patient with delayed virus clear-ance and severe disease. The levels were comparatively less in the other two patients who suf-fered from severe disease but eventually survived.

scholarly journals Synovium-Synovial Fluid Axis in Osteoarthritis Pathology: A Key Regulator of the Cartilage Degradation Process

Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 989
Author(s):  
Dhanashri Ingale ◽  
Priya Kulkarni ◽  
Ali Electricwala ◽  
Alpana Moghe ◽  
Sara Kamyab ◽  
...  
Keyword(s):  
Synovial Fluid ◽  
Early Stage ◽  
Challenge Test ◽  
Degradation Process ◽  
Cartilage Degradation ◽  
Gene Expressions ◽  
Inflammatory Microenvironment ◽  
Protein Levels ◽  
Advanced Stages ◽  
Inflammatory Milieu

Failure of conventional anti-inflammatory therapies in osteoarthritis (OA) underlines the insufficient knowledge about inflammatory mechanisms, patterns and their relationship with cartilage degradation. Considering non-linear nature of cartilage loss in OA, a better understanding of inflammatory milieu and MMP status at different stages of OA is required to design early-stage therapies or personalized disease management. For this, an investigation based on a synovium-synovial fluid (SF) axis was planned to study OA associated changes in synovium and SF along the progressive grades of OA. Gene expressions in synovial-biopsies from different grades OA patients (N = 26) revealed a peak of IL-1β, IL-15, PGE2 and NGF in early OA (Kellgren–Lawrence (KL) grade-I and II); the highest MMP levels were found in advanced stages (KL grade-III and IV). MMPs (MMP-1, 13, 2 and 9) abundance and FALGPA activity estimated in forty SFs of progressive grades showed the maximum protein levels and activity in KL grade-II and III. In an SF challenge test, SW982 and THP1 cells were treated with progressive grade SFs to study the dynamics of MMPs modulation in inflammatory microenvironment; the test yielded a result pattern, which matched with FALGPA and the protein-levels estimation. Inflammatory mediators in SFs served as steering factor for MMP up-regulation. A correlation-matrix of IL-1β and MMPs revealed expressional negative correlation.

scholarly journals Regulation of membrane fusion by the membrane-proximal coil of the t-SNARE during zippering of SNAREpins

2002 ◽  
Vol 158 (5) ◽  
pp. 929-940 ◽  
Author(s):  
Thomas J. Melia ◽  
Thomas Weber ◽  
James A. McNew ◽  
Lillian E. Fisher ◽  
Robert J. Johnston ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Fusion Proteins ◽  
The Other ◽  
Proximal Portion ◽  
Intrinsic State ◽  
Temporal Control ◽  
Helical Bundle ◽  
Proximal Half

We utilize structurally targeted peptides to identify a “tC fusion switch” inherent to the coil domains of the neuronal t-SNARE that pairs with the cognate v-SNARE. The tC fusion switch is located in the membrane-proximal portion of the t-SNARE and controls the rate at which the helical bundle that forms the SNAREpin can zip up to drive bilayer fusion. When the fusion switch is “off” (the intrinsic state of the t-SNARE), zippering of the helices from their membrane-distal ends is impeded and fusion is slow. When the tC fusion switch is “on,” fusion is much faster. The tC fusion switch can be thrown by a peptide that corresponds to the membrane-proximal half of the cognate v-SNARE, and binds reversibly to the cognate region of the t-SNARE. This structures the coil in the membrane-proximal domain of the t-SNARE and accelerates fusion, implying that the intrinsically unstable coil in that region is a natural impediment to the completion of zippering, and thus, fusion. Proteins that stabilize or destabilize one or the other state of the tC fusion switch would exert fine temporal control over the rate of fusion after SNAREs have already partly zippered up.

Direct Nucleation of Crystalline SiGe on Substrates by Reactive Thermal CVD with Si2H6 and GeF4

1997 ◽  
Vol 467 ◽  
Author(s):  
Fumio Yoshizawa ◽  
Kunihiro Shiota ◽  
Daisuke Inoue ◽  
Jun-ichi Hanna
Keyword(s):  
Growth Rate ◽  
Gas Phase ◽  
Heterogeneous Nucleation ◽  
Homogeneous Nucleation ◽  
Film Growth ◽  
Early Stage ◽  
Gaseous Mixture ◽  
The Other ◽  
Thermal Cvd ◽  
Initial Deposition

ABSTRACTPolycrystalline SiGe (poly-SiGe) film growth by reactive thermal CVD with a gaseous mixture of Si2H6 and GeF4 was investigated on various substrates such as Al,Cr, Pt, Si, ITO, ZnO and thermally grown SiO2.In Ge-rich film growth, SEM observation in the early stage of the film growth revealed that direct nucleation of crystallites took place on the substrates. The nucleation was governed by two different mechanisms: one was a heterogeneous nucleation on the surface and the other was a homogeneous nucleation in the gas phase. In the former case, the selective nucleation was observed at temperatures lower than 400°C on metal substrates and Si, where the activation of adsorbed GeF4 on the surface played a major role for the nuclei formation, leading to the selective film growth.On the other hand, the direct nucleation did not always take place in Si-rich film growth irrespective of the substrates and depended on the growth rate. In a growth rate of 3.6nm/min, the high crystallinity of poly-Si0.95Ge0.05in a 220nm-thick film was achieved at 450°C due to the no initial deposition of amorphous tissue on SiO2 substrates.

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