VARIATION IN SENSITIVITY OF AN INTERFERON ASSAY SYSTEM

1967 ◽  
Vol 13 (11) ◽  
pp. 1421-1425
Author(s):  
Robert B. Stewart ◽  
Sunidhkumar S. Gandhi
Keyword(s):  
Chick Embryo ◽  
Cell Cultures ◽  
Dose Response ◽  
Sindbis Virus ◽  
Primary Cultures ◽  
Assay System ◽  
Response Curves ◽  
Challenge Virus ◽  
Embryo Cells ◽  
Altered Sensitivity

Repeated assays of standard preparations of interferon carried out for over a year using primary cultures of chick-embryo cells and Sindbis virus in an assay system showed that cell cultures varied in their sensitivity to interferon. This altered sensitivity was not due to a change in the challenge virus nor to the time of exposure of cells to interferon. An analysis of the data showed that the slope of the dose–response curves remained constant although they could be displaced, indicating changes in sensitivity. Information was also obtained demonstrating that sensitivity of cells to interferon could vary within a single assay.

Effect of interferon on Sindbis virus growth in chick-embryo cell cultures

1969 ◽  
Vol 15 (6) ◽  
pp. 605-610 ◽  
Author(s):  
Robert B. Stewart ◽  
Edward T. Sheaff
Keyword(s):  
Chick Embryo ◽  
Cell Cultures ◽  
Sindbis Virus ◽  
Embryo Cell ◽  
Virus Growth ◽  
Chick Embryo Cell ◽  
Embryo Cells ◽  
Number Of Cells

A study of the effect of interferon on the growth of Sindbis virus in cultures of chick-embryo cells has shown that interferon forms an association with cells (uptake) and that the action of interferon is concentration rather than amount dependent. Evidence has also been obtained that interferon acts to reduce the yield of virus from cells, but does not reduce the number of cells synthesizing virus (all or none effect).

Morphological Examination of a Herpes-type Virus Indigenous for Tree Shrews

1970 ◽  
Vol 28 ◽  
pp. 160-161
Author(s):  
J. P. Brunschwig ◽  
R. M. McCombs ◽  
R. Mirkovic ◽  
M. Benyesh-Melnick
Keyword(s):  
Electron Microscopy ◽  
Soft Tissue ◽  
Chick Embryo ◽  
Soft Tissue Sarcoma ◽  
Cell Cultures ◽  
Tree Shrew ◽  
Type Virus ◽  
Morphological Examination ◽  
Tree Shrews ◽  
Embryo Cells

A new virus, established as a member of the herpesvirus group by electron microscopy, was isolated from spontaneously degenerating cell cultures derived from the kidneys and lungs of two normal tree shrews. The virus was found to replicate best in cells derived from the homologous species. The cells used were a tree shrew cell line, T-23, which was derived from a spontaneous soft tissue sarcoma. The virus did not multiply or did so poorly for a limited number of passages in human, monkey, rodent, rabbit or chick embryo cells. In the T-23 cells, the virus behaved as members of the subgroup B of herpesvirus, in that the virus remained primarily cell associated.

Differential response of primary cultures of breast carcinomas to lapatinib in an in vitro chemoresponse assay

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 1115-1115
Author(s):  
L. M. Hancher ◽  
P. R. Ervin ◽  
S. L. Brower
Keyword(s):  
Cell Lines ◽  
Dose Response ◽  
Response Rate ◽  
Primary Cultures ◽  
Breast Carcinomas ◽  
Human Breast ◽  
Response Curves ◽  
Her 2 ◽  
Dose Response Curves

1115 Background: Lapatinib (Tykerb) is a small molecule tyrosine kinase inhibitor that targets the intracellular domain of the epidermal growth factor receptor and HER-2, thereby inhibiting both growth and survival signaling pathways. Lapatinib is currently FDA-approved to treat HER-2-positive breast cancer previously treated with anthracycline and taxane therapies and trastuzumab. Due to the low population response rate of lapatinib, an integrated biomarker that can identify patients with an increased likelihood for response would be of great clinical utility. The current study describes an in vitro chemoresponse assay developed to predict sensitivity and resistance of primary cultures of human breast tumor specimens to lapatinib. Methods: The chemoresponse assay (ChemoFx) for lapatinib was developed using four different immortalized carcinoma cell lines (SK-OV3, BT474, MDA-MB-231, MCF7). In addition to cell lines, the chemoresponse assay was also performed on 55 first passage primary cultures of human breast carcinomas. All cultures were confirmed to contain keratin-positive epithelial cells using fluorescence immunocytochemistry. Cell lines and specimens were treated with a 10 dose concentration range of lapatinib for 72 hours and stained with DAPI; remaining live cells were counted on an inverted fluorescent imaging system. Resulting dose-response curves were analyzed and categorized as responsive, intermediate responsive, or non-responsive using a proprietary scoring algorithm. Results: All four cell lines (BT474, MDA-MB-231, MCF7, SK-OV3) were responsive to lapatinib treatment, with EC50 values of approximately 10 uM. Dose-response curves of the 55 primary breast cultures revealed that 9% of the specimens tested were responsive to lapatinib, 15% had an intermediate response, and 76% were non-responsive. These results are consistent with a reported clinical response rate of 10% for lapatinib. Conclusions: Initial results with the described integrated cell-based assay demonstrate that in vitro chemoresponse testing may be useful in predicting patient response to lapatinib. This type of in vitro biomarker is likely to increase the efficacy of the current chemotherapy decision-making process for oncologists and their patients. No significant financial relationships to disclose.

Use of an in vitro chemoresponse assay to define a subset of colorectal carcinomas responsive to cetuximab

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e15127-e15127
Author(s):  
S. D. Rice ◽  
P. R. Ervin ◽  
S. L. Brower
Keyword(s):  
Cell Lines ◽  
Dose Response ◽  
Response Rate ◽  
Primary Cultures ◽  
Colorectal Tumor ◽  
Colorectal Carcinomas ◽  
Response Curves ◽  
Drug Mechanism ◽  
Dose Response Curves

e15127 Background: Cetuximab (Erbitux) is a chimeric monoclonal antibody that binds to the extracellular domain of the epidermal growth factor receptor. This interaction interferes with ligand binding and activation of the receptor blocking the downstream signaling of EGFR and impairing cell growth and proliferation. Cetuximab also has been shown to mediate antibody dependent cellular cytotoxicity. Thus, a singular approach to drug mechanism likely would not capture the true effects of cetuximab. Cetuximab is FDA-approved to treat head and neck cancer and colorectal carcinomas and is being evaluated for use in non-small cell lung and endometrial cancer. Due to the low population response rate of cetuximab, an integrated biomarker that can identify patients with an increased likelihood for response would be of great clinical utility. The current study describes an in vitro chemoresponse assay to predict response of primary cultures of human colorectal tumor specimens to cetuximab. Methods: The chemoresponse assay (ChemoFx) was developed using four different immortalized carcinoma cell lines (NCI-H292, NCI-H522, NCI-H1666, Calu3). The chemoresponse assay was also performed on 54 first passage primary cultures of human colorectal tumor specimens. Cell lines and specimens were treated with a 10 dose concentration range of cetuximab for 72 hours, stained with a nuclear dye, and remaining post-treatment live cells were counted. Resulting dose-response curves were analyzed. Results: Two of the examined cell lines showed response to cetuximab treatment; EC50 values for NCI-H292 and NCI-H1666 were 825nM and 13nM, respectively. NCI-H522 and Calu3 were deemed non-responsive to cetuximab. Dose-response curves of the 54 primary colorectal cultures revealed that 8% of the cultures tested were responsive to cetuximab, 22% had an intermediate response, and 70% were deemed non-responsive. These results are consistent with a reported clinical response rate of 11% for cetuximab in colorectal carcinoma patients. Conclusions: Initial results demonstrate that in vitro chemoresponse testing may be useful in predicting patient response to cetuximab. This could increase the efficacy of the current chemotherapy decision-making process for oncologists and their patients. No significant financial relationships to disclose.

UV irradiation of interferon-treated chick embryo cells enhances sindbis virus growth

1976 ◽  
Vol 52 (4) ◽  
pp. 351-354
Author(s):  
Y. Umino ◽  
S. Kohno ◽  
S. Saito
Keyword(s):  
Chick Embryo ◽  
Uv Irradiation ◽  
Sindbis Virus ◽  
Virus Growth ◽  
Embryo Cells

Secretion of transferrin in ovine seminiferous tubule cell cultures in response to FSH: influence of breed, season of birth and age of lambs

1993 ◽  
Vol 5 (1) ◽  
pp. 83 ◽  
Author(s):  
C Monet-Kuntz ◽  
I Fontaine
Keyword(s):  
Cell Cultures ◽  
Dose Response ◽  
Sertoli Cells ◽  
Seminiferous Tubule ◽  
Seminiferous Tubules ◽  
Testis Weight ◽  
Season Of Birth ◽  
Tubule Cell ◽  
Response Curves ◽  
Testicular Weight

The response of lamb Sertoli cells to follicle stimulating hormone (FSH) was investigated by measuring transferrin secretion in seminiferous tubule cell cultures throughout the non-pubertal and the prepubertal periods. Cells could be cultured from birth until they attained a testicular weight of 19 g. The characteristics of individual dose-response curves were compared according to the breed, season of birth and testicular weight of the lambs. At the same season of birth and within a given testis weight range, dose-response curves of Romanov and Ile-de-France lambs were similar. Within a given testis weight range, spring-born animals exhibited a higher maximal transferrin secretion than autumn-born lambs, but the ED50 was similar. The main factor of variation of the dose-response curve parameters was the testicular weight of the lambs: the amplitude of FSH response increased 3-fold from a testicular weight of 6 g onwards, i.e. from the appearance of spermatogonia in seminiferous tubules. The ED50 increased 5-fold from 11 g onwards, i.e. from the beginning of the prepubertal period. Thus, Sertoli cells become less sensitive to FSH as spermatogenesis develops in seminiferous tubules. This phenomenon is largely the result of higher phosphodiesterase activity and is greatly reduced by 1-methyl-3-isobutyl-xanthine (MIX).

Sign in / Sign up

Export Citation Format

Share Document