A quantitative study of the chorioallantoic membrane reaction in the chick embryo

1966 ◽  
Vol 163 (993) ◽  
pp. 555-563 ◽  
Keyword(s):  
Chick Embryo ◽  
Chorioallantoic Membrane ◽  
Cell Types ◽  
Variable Number ◽  
Logarithmic Scale ◽  
Focal Lesions ◽  
Specific Test ◽  
The Individual ◽  
Response Line ◽  
Different Cell Types

When a suspension of living adult chick leucocytes is placed in contact with the chorioallantoic membrane (CAM) of a developing chick embryo, a variable number of white focal lesions appear a few days later. The number of foci is positively correlated with the number of cells in the inoculum. The phenomenon is known to be an expression of an immunological reaction of the grafted cells against the host. F. M. Burnet and his colleagues have suggested that each focus results from the immunological activity of one and only one cell. If this presumption were confirmed the CAM system would gain in usefulness, in particular for the isolation of clones of immunologically competent cells. In the present work this ‘single-hit’ hypothesis has been subjected to a specific test of its biometrical consequences. On the single-hit model the response should be proportional to the dose. Equivalently, on the logarithmic scale of measurement adopted in these experiments, the fitted dose-response line should show a slope of unity. When suitable precautions were taken to ensure thorough dispersion of donor cells, it was possible to verify the predicted relationship. The only qualification which should be attached to the conclusions concerns the possibility of co-operative action between two different cell types, one of which is very abundant relative to the other. With this proviso, it may be concluded that the individual focus observed in the CAM reaction does indeed result from the activity of a single cell.

Role of Transcriptional Read-Through in PRE Activity in Drosophila melanogaster

Acta Naturae ◽  
2016 ◽  
Vol 8 (2) ◽  
pp. 79-86 ◽  
Author(s):  
P. V. Elizar’ev ◽  
D. V. Lomaev ◽  
D. A. Chetverina ◽  
P. G. Georgiev ◽  
M. M. Erokhin
Keyword(s):  
Dna Sequences ◽  
Cell Types ◽  
Transcription Terminator ◽  
Response Elements ◽  
Polycomb Response Elements ◽  
The Individual ◽  
Multicellular Organisms ◽  
Different Cell Types ◽  
Main Factor

Maintenance of the individual patterns of gene expression in different cell types is required for the differentiation and development of multicellular organisms. Expression of many genes is controlled by Polycomb (PcG) and Trithorax (TrxG) group proteins that act through association with chromatin. PcG/TrxG are assembled on the DNA sequences termed PREs (Polycomb Response Elements), the activity of which can be modulated and switched from repression to activation. In this study, we analyzed the influence of transcriptional read-through on PRE activity switch mediated by the yeast activator GAL4. We show that a transcription terminator inserted between the promoter and PRE doesnt prevent switching of PRE activity from repression to activation. We demonstrate that, independently of PRE orientation, high levels of transcription fail to dislodge PcG/TrxG proteins from PRE in the absence of a terminator. Thus, transcription is not the main factor required for PRE activity switch.

scholarly journals The Microtubule Plus-End Proteins EB1 and Dynactin Have Differential Effects on Microtubule Polymerization

2003 ◽  
Vol 14 (4) ◽  
pp. 1405-1417 ◽  
Author(s):  
Lee A. Ligon ◽  
Spencer S. Shelly ◽  
Mariko Tokito ◽  
Erika L.F. Holzbaur
Keyword(s):  
Cultured Cells ◽  
Cell Types ◽  
Microtubule Dynamics ◽  
In Vitro Assays ◽  
Nucleation Effect ◽  
Microtubule Polymerization ◽  
The Individual ◽  
Different Cell Types ◽  
Dynactin Complex

Several microtubule-binding proteins including EB1, dynactin, APC, and CLIP-170 localize to the plus-ends of growing microtubules. Although these proteins can bind to microtubules independently, evidence for interactions among them has led to the hypothesis of a plus-end complex. Here we clarify the interaction between EB1 and dynactin and show that EB1 binds directly to the N-terminus of the p150Glued subunit. One function of a plus-end complex may be to regulate microtubule dynamics. Overexpression of either EB1 or p150Glued in cultured cells bundles microtubules, suggesting that each may enhance microtubule stability. The morphology of these bundles, however, differs dramatically, indicating that EB1 and dynactin may act in different ways. Disruption of the dynactin complex augments the bundling effect of EB1, suggesting that dynactin may regulate the effect of EB1 on microtubules. In vitro assays were performed to elucidate the effects of EB1 and p150Glued on microtubule polymerization, and they show that p150Gluedhas a potent microtubule nucleation effect, whereas EB1 has a potent elongation effect. Overall microtubule dynamics may result from a balance between the individual effects of plus-end proteins. Differences in the expression and regulation of plus-end proteins in different cell types may underlie previously noted differences in microtubule dynamics.

Comparative studies of insulin binding to receptor from adipocytes, hepatocytes, monocytes and erythrocytes from the pig

1988 ◽  
Vol 118 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Elisabeth Hjøllund ◽  
Bjørn Richelsen ◽  
Oluf Pedersen
Keyword(s):  
Steady State ◽  
Receptor Binding ◽  
Specific Binding ◽  
Insulin Binding ◽  
Cell Types ◽  
Target Cells ◽  
Suitable Model ◽  
The Individual ◽  
Different Cell Types ◽  
Specific Insulin

Abstract. We have described the receptor binding of A 14-labelled [125I]insulin to viable adipocytes, hepatocytes, monocytes and erythrocytes from the pig. For all cell types the binding was of high affinity, specific for insulin, the non-specific binding low and degradation of insulin in the medium was minimal. At 24°C, steady state insulin binding was achieved in all four cell types. At 37°C, steady state insulin binding could be measured to adipocytes and hepatocytes. Specific insulin binding levels and receptor affinity for blood and fat cells from the pig are comparable to that in human cells, whereas differences, especially according to affinity, exist between pig and rat cell insulin receptor binding. It is therefore concluded that the pig is a more suitable model for studies of insulin binding in man than rodents. Finally, no correlations between the individual binding levels to the different cell types were observed. Hence, measurement of insulin binding to the easier available blood cells cannot replace studies of insulin binding to target cells of insulin.

scholarly journals SYNERGISTIC ACTION OF HEMOPHILUS INFLUENZAE SUIS AND THE SWINE INFLUENZA VIRUS ON THE CHICK EMBRYO

1943 ◽  
Vol 77 (1) ◽  
pp. 7-20 ◽  
Author(s):  
Frederik B. Bang
Keyword(s):  
Influenza Virus ◽  
Chick Embryo ◽  
Synergistic Effect ◽  
Swine Influenza Virus ◽  
Chorioallantoic Membrane ◽  
Swine Influenza ◽  
Human Influenza ◽  
Human Influenza Virus ◽  
Hemophilus Influenzae ◽  
The Individual

The synergistic effect of Hemophilus influenzae suis and swine influenza virus in the pig can be reproduced by the inoculation of these agents on the chorioallantoic membrane of 9 to 10 day old chick embryos. Two strains of human influenza virus that were studied failed to substitute for the swine virus in the synergistic reaction. No loss of synergistic effect was noted when the swine influenza virus was put through 11 chick embryo passages. Recently isolated and old stock strains of Hemophilus were equally able to enhance the effect of the virus. Heat-killed cultures of H. influenzae suis can be substituted for the bacterial component of the reaction. Infection of the embryo with swine influenza virus predisposes to infection with H. influenzae suis. The combination of H. influenzae suis and swine influenza virus causes a selective destruction of the embryo lungs, not produced by the individual components. This pneumonia exhibits the essential features of the natural disease.

Auditory and Cytocochlear Correlates of Inner Ear Disorders

1994 ◽  
Vol 110 (6) ◽  
pp. 530-538 ◽  
Author(s):  
Harold F. Schuknecht
Keyword(s):  
Pure Tone ◽  
Organ Of Corti ◽  
Cell Types ◽  
Cell Type ◽  
Focal Lesions ◽  
Frequency Scale ◽  
Principal Effect ◽  
Single Cell Type ◽  
Different Cell Types ◽  
Pure Tone Threshold

Pure-tone threshold audiograms showing sensorineural hearing loss, when plotted on a data-based anatomic frequency scale, show a close spatial correlation with their respective cytocochieograms. Whereas most of the cochleae show pathology of several different cell types, a sufficient number show losses that involve predominantly a single cell type, which permits the following deductions: (1) focal lesions of the organ of Corti are strongly tonotopic and are responsible for those instances of abrupt pure-tone threshold losses; (2) lesions of the stria vascuiaris show no tonotopic organization but lead to flat pure-tone threshold losses; and (3) the principal effect of neuronal losses is a diminished capability for word recognition. There Is an indeterminate group where no pathologic correlate can be identified by light microscopy.

scholarly journals Anthracyclins Increase PUFAs: Potential Implications in ER Stress and Cell Death

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1163
Author(s):  
David Balgoma ◽  
Fredrik Kullenberg ◽  
Carlemi Calitz ◽  
Maria Kopsida ◽  
Femke Heindryckx ◽  
...  
Keyword(s):  
Cell Death ◽  
Er Stress ◽  
Cell Lines ◽  
De Novo ◽  
Primary Liver Cancer ◽  
Cell Types ◽  
De Novo Lipogenesis ◽  
The Individual ◽  
Different Cell Types ◽  
The Relationship

Metabolic and personalized interventions in cancer treatment require a better understanding of the relationship between the induction of cell death and metabolism. Consequently, we treated three primary liver cancer cell lines with two anthracyclins (doxorubicin and idarubin) and studied the changes in the lipidome. We found that both anthracyclins in the three cell lines increased the levels of polyunsaturated fatty acids (PUFAs) and alkylacylglycerophosphoethanolamines (etherPEs) with PUFAs. As PUFAs and alkylacylglycerophospholipids with PUFAs are fundamental in lipid peroxidation during ferroptotic cell death, our results suggest supplementation with PUFAs and/or etherPEs with PUFAs as a potential general adjuvant of anthracyclins. In contrast, neither the markers of de novo lipogenesis nor cholesterol lipids presented the same trend in all cell lines and treatments. In agreement with previous research, this suggests that modulation of the metabolism of cholesterol could be considered a specific adjuvant of anthracyclins depending on the type of tumor and the individual. Finally, in agreement with previous research, we found a relationship across the different cell types between: (i) the change in endoplasmic reticulum (ER) stress, and (ii) the imbalance between PUFAs and cholesterol and saturated lipids. In the light of previous research, this imbalance partially explains the sensitivity to anthracyclins of the different cells. In conclusion, our results suggest that the modulation of different lipid metabolic pathways may be considered for generalized and personalized metabochemotherapies.

The expression of human interferon alpha genes

1984 ◽  
Vol 307 (1132) ◽  
pp. 217-226 ◽  
Keyword(s):  
Cell Types ◽  
Human Interferon ◽  
Striking Difference ◽  
Cell Type ◽  
Flanking Sequence ◽  
Major Fraction ◽  
Leukaemic Cells ◽  
Ifn Γ ◽  
The Individual ◽  
Different Cell Types

We have determined the levels of mRNAs for IFN-β, IFN-γ and various α-IFNs (IFN-α1, -α2, -α4, -α5, -α6, -α7, -α8 and -α14) in normal and leukaemic human blood leucocytes and several cell lines induced in different fashions. The ratio of α to β IFN transcripts varied greatly, depending on the cell type. The levels of the individual IFN-α RNAs were very different: IFN-α1, -α2 and -α4 RNAs constituted the major fraction of the IFN-α transcripts measured, while IFN-α6, -α7, -α8 and -α14 were minor components in normal, induced leucocytes. M oreover, there was a striking difference in the proportion of individual IFN-α mRNA species in different cell types, in particular between normal and leukaemic cells; for example all cases of myeloblastic leukaemia examined showed a high expression of IFN-α14. Use of different induction protocols did not significantly affect the proportion of IFN mRNAs. Analysis of the human IFN -α1 gene by reversed genetics led to the identification of a segment of 5' flanking sequence between positions 117 and 68 upstream of the cap site which is required for inducibility by virus.

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

Processing and Characterization of Recombinant von Willebrand Factor Expressed in Different Cell Types Using a Vaccinia Virus Vector

1992 ◽  
Vol 67 (01) ◽  
pp. 154-160 ◽  
Author(s):  
P Meulien ◽  
M Nishino ◽  
C Mazurier ◽  
K Dott ◽  
G Piétu ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Von Willebrand Factor ◽  
Human Fibroblasts ◽  
Active Form ◽  
Cell Types ◽  
Biologically Active ◽  
L Cells ◽  
Von Willebrand ◽  
Different Cell Types ◽  
Willebrand Factor

SummaryThe cloning of the cDNA encoding von Willebrand factor (vWF) has revealed that it is synthesized as a large precursor (pre-pro-vWF) molecule and it is now clear that the prosequence or vWAgll is responsible for the intracellular multimerization of vWF. We have cloned the complete vWF cDNA and expressed it using a recombinant vaccinia virus as vector. We have characterized the structure and function of the recombinant vWF (rvWF) secreted from five different cell types: baby hamster kidney (BHK), Chinese hamster ovary (CHO), human fibroblasts (143B), mouse fibroblasts (L) and primary embryonic chicken cells. Forty-eight hours after infection, the quantity of vWF antigen found in the cell supernatant varied from 3 to 12 U/dl depending on the cell type. By SDS-agarose gel electrophoresis, the percentage of high molecular weight forms of vWF varied from 39 to 49% relative to normal plasma for BHK, CHO, 143B and chicken cells but was less than 10% for L cells. In all cell types, the two anodic subbands of each multimer were missing. The two cathodic subbands were easily detected only in BHK and L cells. By SDS-PAGE of reduced samples, pro-vWF was present in similar quantity to the fully processed vWF subunit in L cells, present in moderate amounts in BHK and CHO and in very low amounts in 143B and chicken cells. rvWF from all cells bound to collagen and to platelets in the presence of ristocetin, the latter showing a high correlation between binding efficiency and degree of multimerization. rvWF from all cells was also shown to bind to purified FVIII and in this case binding appeared to be independent of the degree of multimerization. We conclude that whereas vWF is naturally synthesized only by endothelial cells and megakaryocytes, it can be expressed in a biologically active form from various other cell types.

Investigation of duck plague virus in hoar areas of Bangladesh

2020 ◽  
Vol 26 (1-2) ◽  
pp. 73-78
Author(s):  
A Hossen ◽  
MH Rahman ◽  
MZ Ali ◽  
MA Yousuf ◽  
MZ Hassan ◽  
...  
Keyword(s):  
Cytopathic Effect ◽  
Clinical Sample ◽  
Chorioallantoic Membrane ◽  
Clinical Samples ◽  
Isolation And Identification ◽  
Duck Plague Virus ◽  
Pcr Method ◽  
Polymerase Chain ◽  
The Individual ◽  
Free Ranging

Duck plague (DP) is the most important infectious disease of geese, ducks and free-ranging water birds. The present study was conducted to determine the prevalence of duck plague virus followed by isolation and identification. For these purposes, a total of 155 cloacal swabs samples were collected randomly from duck of different haor areas of Bangladesh including 45 (41 surveillance and 4 clinical) samples from Netrokona; 42 (40 surveillance and 2 clinical) samples from Kishoregonj; 30 samples from Brahmanbaria and 38 samples from Sunamganj. The samples were processed and pooled (1:5 ratio) for initial screening of target polymerase gene of duck plague virus by polymerase chain reaction (PCR) method. All the samples of a positive pool were then tested individually for identifying the individual positive samples. The result showed that out of 155 samples, 41 (26.45%) were found positive in which 17 were from Netrokona, where 15 (36.58%) were from surveillance samples and 2 (50%) were from clinical sample; 16 were from Kishoregonj, where 14 (35%) were from surveillance samples and 2 (100%) were from clinical sample; 2 (6.6%) were from Brahmanbaria and 5 (13.15%) were from Sunamganj. These positive samples were inoculated into 9-10 days embryonated duck eggs (EDE) through chorioallantoic membrane (CAM) route for the isolation of virus. The EDE died earlier was also chilled, and in a similar way, the CAMs were collected and again performed PCR for id entification of virus. Out of 41 PCR positive samples, 26 samples were isolated and reconfirmed by PCR. Subsequently, DPV was isolated in primary duck embryo fibroblasts cell culture and confirmed by observing cytopathic effect (CPE). Bang. J. Livs. Res. Vol. 26 (1&2), 2019: P. 73-78

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