scholarly journals Cyclic Adenosine Monophosphate and Alteration of Chinese Hamster Ovary Cell Morphology: a Rapid, Sensitive In Vitro Assay for the Enterotoxins of Vibrio cholerae and Escherichia coli

1974 ◽  
Vol 10 (2) ◽  
pp. 320-327 ◽  
Author(s):  
Richard L. Guerrant ◽  
Laurence L. Brunton ◽  
Terry C. Schnaitman ◽  
Lionel I. Rebhun ◽  
Alfred G. Gilman
Keyword(s):  
Escherichia Coli ◽  
Cell Morphology ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
In Vitro Assay ◽  
Ovary Cell ◽  
Vitro Assay

scholarly journals Rapid Bioassay for Detection of Thyroid-Stimulating Antibodies Using Cyclic Adenosine Monophosphate-Gated Calcium Channel and Aequorin

2015 ◽  
Vol 4 (1) ◽  
pp. 14-19 ◽  
Author(s):  
Naohiro Araki ◽  
Mitsuru Iida ◽  
Nobuyuki Amino ◽  
Shinji Morita ◽  
Akane Ide ◽  
...  
Keyword(s):  
Calcium Channel ◽  
Hormone Receptor ◽  
Chinese Hamster ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Thyroid Stimulating Hormone ◽  
Ovary Cell ◽  
Intracellular Camp ◽  
Thyroid Stimulating Antibodies ◽  
Stimulating Hormone

Background: Thyroid-stimulating antibodies (TSAb) are known to be responsible for hyperthyroidism in Graves' disease (GD). The conventional methods to measure TSAb depend on cell-based assays that require cumbersome procedures and a sterilized tissue culture technique. The aim of the present study was to develop a ready-to-use cell-based assay for measuring TSAb activity without requiring sterilized conditions. Methods: We developed a new assay kit using a frozen Chinese hamster ovary cell line expressing the thyroid-stimulating hormone receptor, cyclic adenosine monophosphate (cAMP)-gated calcium channel and aequorin, tentatively named the aequorin TSAb assay. Activated stimulatory G-protein-coupled adenylate cyclase increases intracellular cAMP, which then binds to the cyclic nucleotide-gated calcium channel. Activation of this channel allows Ca2+ to enter the cell, and the influx of Ca2+ can be measured with aequorin, which is quantified by a luminometer. Results can be obtained in only 4 h without sterilized conditions. TSAb activities were expressed by international units using the NIBSC 08/204 standard. Results: Positive results of aequorin TSAb were obtained in 197 of 199 (98.9%) of untreated patients with GD. Only 1 of 42 (2.3%) patients with painless thyroiditis had a weakly positive aequorin TSAb. All 45 patients with subacute thyroiditis and 185 normal subjects showed negative aequorin TSAb. As for chronic thyroiditis, all 52 euthyroid patients showed negative aequorin TSAb, but 8 of 50 (16.0%) hypothyroid patients had a positive reaction. However, these positive reactions were not induced by serum thyroid-stimulating hormone (TSH) and were thought to be induced by the stimulating activity of anti-TSH receptor immunoglobulins. Conventional porcine TSAb and Elecsys thyroid-stimulating hormone receptor antibodies were positive in 69.3 and 95.5% of GD, respectively. Conclusion: The aequorin TSAb assay was positive in 98.9% of GD and was more sensitive than the conventional assay. This assay can be conducted in only 4 h without sterilized conditions and is practically useful in general clinical laboratories.

THE ACTION OF DIBUTYRYL CYCLIC 3′,5′-ADENOSINE MONOPHOSPHATE ON THE MOUSE THYROID GLAND IN VITRO

1970 ◽  
Vol 47 (3) ◽  
pp. 333-338 ◽  
Author(s):  
PAT KENDALL-TAYLOR ◽  
D. S. MUNRO
Keyword(s):  
Thyroid Gland ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Adenosine Monophosphate ◽  
Thyroid Stimulating Hormone ◽  
In Vitro Assay ◽  
Vitro Assay ◽  
Layer Chromatography ◽  
Mouse Thyroid

SUMMARY The effects of dibutyryl cyclic 3′,5′-adenosine monophosphate (DBc-AMP) on the mouse thyroid gland have been investigated in the in-vitro assay of Brown & Munro (1967). The distribution of 131I-labelled compounds in the glands and the supporting medium have been analysed by thin-layer chromatography and the changes induced by cyclic 3′,5′-adenosine monophosphate (c-AMP), DBc-AMP or thyroid-stimulating hormone (TSH) compared. The release of 131I was increased when the glands were incubated with DBc-AMP, c-AMP or TSH. The potency of DBc-AMP was approximately 50 times that of c-AMP on a basis of molarity. Like TSH, DBc-AMP increased the proportion of iodothyronines in the system as a whole, whereas c-AMP had little effect. The possible explanations for this are discussed.

Further characterization of the in vitro assay for inhibitors of metabolic cooperation in the Chinese hamster V79 cell line

1985 ◽  
Vol 6 (3) ◽  
pp. 361-366 ◽  
Author(s):  
C. Jone ◽  
J.E. Trosko ◽  
C.F. Aylsworth ◽  
L. Parker ◽  
C.C. Chang
Keyword(s):  
Cell Line ◽  
Chinese Hamster ◽  
In Vitro Assay ◽  
Metabolic Cooperation ◽  
Vitro Assay ◽  
V79 Cell

scholarly journals Chinese hamster ovary cell mutants with temperature-sensitive defects in endocytosis. I. Loss of function on shifting to the nonpermissive temperature.

1986 ◽  
Vol 103 (6) ◽  
pp. 2283-2297 ◽  
Author(s):  
C F Roff ◽  
R Fuchs ◽  
I Mellman ◽  
A R Robbins
Keyword(s):  
Chinese Hamster Ovary Cell ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster ◽  
Ovary Cell ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Nonpermissive Temperature ◽  
Phenotypic Changes ◽  
Endosomal Acidification

We have isolated three independent Chinese hamster ovary cell mutants (B3853, I223, and M311) with temperature-sensitive, pleiotropic defects in receptor-mediated endocytosis. Activities affected at 41 degrees C include uptake via the D-mannose 6-phosphate receptor, accumulation of Fe from diferric transferrin, uptake of alpha 2-macroglobulin, compartmentalization of newly synthesized acid hydrolases, resistance to ricin, and sensitivity to diphtheria and Pseudomonas toxins and modeccin. The three mutants also displayed decreased sialylation of some secreted glycoproteins at 41 degrees C, reminiscent of the nonconditional mutant DTG1-5-4 that showed both endocytic and Golgi-associated defects (Robbins, A.R., C. Oliver, J.L. Bateman, S.S. Krag, C.J. Galloway, and I. Mellman, 1984, J. Cell Biol., 99:1296-1308). Phenotypic changes were detectable within 30 min after transfer of the mutants to 41 degrees C; maximal alteration of most susceptible functions was obtained 4 h after temperature shift. At 39 degrees C, the mutants exhibited many but not all of the changes manifested at 41 degrees C; resistance to diphtheria and Pseudomonas toxins required the higher temperature. Analysis of cell hybrids showed that B3853 and DTG1-5-4 are in one complementation group ("End1"); M311 and I223 are in another ("End2"). In the End1 mutants, loss of endocytosis correlated with complete loss of ATP-dependent endosomal acidification in vitro; in the End 2 mutants partial loss of acidification was observed. At the nonpermissive temperature, residual levels of endocytic activity in B3853 and M311 were nearly identical; thus, we conclude that the differences measured in endosomal acidification in vitro reflect the different genetic loci affected, rather than the relative severity of the genetic lesions. The mutations in M311 and I223 appear to have different effects on the same protein; in I223 (but not in M311) the full spectrum of phenotypic changes could be produced at the permissive temperature by inhibition of protein synthesis.

scholarly journals Characterization of a Chinese Hamster Ovary Cell Line Developed by Retroviral Insertional Mutagenesis That Is Resistant to Sindbis Virus Infection

1999 ◽  
Vol 73 (6) ◽  
pp. 4919-4924 ◽  
Author(s):  
Jia-Tsrong Jan ◽  
Andrew P. Byrnes ◽  
Diane E. Griffin
Keyword(s):  
Heparan Sulfate ◽  
Cell Line ◽  
Virus Replication ◽  
Chinese Hamster Ovary ◽  
Sindbis Virus ◽  
Insertional Mutagenesis ◽  
Cultured Cells ◽  
Chinese Hamster ◽  
Ovary Cell

ABSTRACT The alphavirus Sindbis virus (SV) has a wide host range and infects many types of cultured cells in vitro. The outcome of infection is dependent on the strain of virus used for infection and the properties of the cells infected. To identify cellular determinants of susceptibility to SV infection we mutagenized Chinese hamster ovary (CHO) cells by retroviral insertion with a vector containing the neomycin resistance gene that allowed selection for integration into transcriptionally active genes. Cells were then selected for survival after infection with SV. The most resistant cell line (CHO-18.4m) exhibited delayed virus replication and virus-induced cell death, had a single retroviral insertion, and was defective in SV binding to the cell surface. Further analysis revealed that CHO-18.4m cells were deficient in the expression of the sulfated glycosaminoglycans heparan sulfate and chondroitin sulfate. This further confirms the importance of heparan sulfate as an attachment molecule for SV in vitro and demonstrates the usefulness of this technique for identifying cellular genes that are important for virus replication.

scholarly journals Evaluating the toxicity of TiO2-based nanoparticles to Chinese hamster ovary cells and Escherichia coli: a complementary experimental and computational approach

2017 ◽  
Vol 8 ◽  
pp. 2171-2180 ◽  
Author(s):  
Alicja Mikolajczyk ◽  
Natalia Sizochenko ◽  
Ewa Mulkiewicz ◽  
Anna Malankowska ◽  
Michal Nischk ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Chinese Hamster Ovary ◽  
Second Generation ◽  
Bimetallic Nanoparticles ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Computational Approach ◽  
Toxicity Tests ◽  
Surface Modified

Titania-supported palladium, gold and bimetallic nanoparticles (second-generation nanoparticles) demonstrate promising photocatalytic properties. However, due to unusual reactivity, second-generation nanoparticles can be hazardous for living organisms. Considering the ever-growing number of new types of nanoparticles that can potentially contaminate the environment, a determination of their toxicity is extremely important. The main aim of presented study was to investigate the cytotoxic effect of surface modified TiO2-based nanoparticles, to model their quantitative nanostructure–toxicity relationships and to reveal the toxicity mechanism. In this context, toxicity tests for surface-modified TiO2-based nanoparticles were performed in vitro, using Gram-negative bacteria Escherichia coli and Chinese hamster ovary (CHO-K1) cells. The obtained cytotoxicity data were analyzed by means of computational methods (quantitative structure–activity relationships, QSAR approach). Based on a combined experimental and computational approach, predictive models were developed, and relationships between cytotoxicity, size, and specific surface area (Brunauer–Emmett–Teller surface, BET) of nanoparticles were discussed.

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