Long-term preservation of transfecting activity of avian sarcoma proviral DNA.

The integrated proviral DNA of avian sarcoma virus (ASV) in host cell chromosomes has been isolated and stored in saline sodium citrate (SSC) solution or in 70% ethanol at 4 degrees C in a refrigerator over 4 years. This DNA was assayed by transfection of chick embryo cells(CEC). The biological activity of cellular transformation by the stored DNA was compared with that of a fresh isolate of the proviral DNA. The efficiency of the transfection by each DNA was almost the same.</p

Effect of glucosamine on phenotype mixing of vesicular stomatitis virus with avian sarcoma virus

The effect of glucosamine on phenotypic mixing between vesicular stomatitis virus (VSV) and avian sarcoma virus (ASV) was studied. Phenotypic mixing decreased with increase in glucosamine concentration, and, in the presence of 20 mM glucosamine, was no longer detectable. In the presence of 20 mM glucosamine, cells still produced 10(2)--10(3) focus forming units (FFU) of ASV and 10(6) plaque forming units (PFU) of VSV per milliliter. These results suggest that cells producing a relatively large amount of ASV (more than 10(3) FFU/ml) are essential for phenotypic mixing of VSV with ASV.</p

Establishment and characterization of a virus-free chick cell line.

A line of chick embryo cells (CEC) was obtained from CEC treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The cells, designated CHCC-OU2, were contact-inhibited, formed no colony in soft agar and did not produce tumors when inoculated into syngeneic chickens. The electron microscopic examination and reverse transcriptase assay showed no virus production from the cells. Subgroup A avian sarcoma virus (ASV) and Newcastle disease virus replicated well in the cells of this cell line.</p

Rescue of infectious virus from nonproducer Rous cells by chick cellular DNA.

The rescue of infectious virus from nonproducer BH RSV(-) cells by chick cellular DNA was attempted in order to investigate the functional state of endogenous and exogenous retroviral genes integrated within the cellular DNA. No infectious virus was rescued by transfection with DNAs of chick helper factor (chf)-negative chick embryo cells (CEC), chf-positive CEC or uninfected CEC producing endogenous Rous associated virus (RAV-0). On the other hand, infectious Rous viruses with the phenotype of RAV-0 and RAV-1 were rescued by transfection with DNAs of CEC which had been infected with RAV-0 and RAV-1. From these results, it seems that exogenous retroviral genes integrated in the cellular DNA are expressed rather easily by transfection while those present endogenously are not.</p

Fluorescence and Electron Microscopic Studies of the Cytoskeletal Organi­zation of Normal, Established and Transformed Chick Embryo Cells

The cytoskeletons of two established chick embryo cell (CEC) lines were examined by fluorescence and electron microscopy and compared with those of control cells and cells transformed by Rous sarcoma virus (RSV). In normal CEC, many stress fibers were observed. On the other hand, stress fibers were disorganized in nontransformed spontaneously established CEC, non-tumorigenic CEC partially transformed with a chemical carcinogen, and tumorigenic RSV-transformed CEC. In the normal CEC, actin filaments formed several bundles along the processes of the cell. Stereo-images of the peripheral region revealed bundles of filaments which were located along the attached side to the substrate. A fine well preserved network of filaments was also observed. On the other hand, in spontaneously established, partially transformed and RSV-transformed CEC, a fine network of filaments, but no actin cables, was found. These results support previous evidence that the cytoskeletal changes themselves are not directly related to the transformation or tumorigenicity of cells. </p

Human papillomavirus DNA in cell lines derived from malignancies.

The presence of high-risk types of human papillomavirus (HPV) 16, 18 and 33 in cell lines established from several malignancies including 5 of cervical cancer and 6 of head and neck cancer was studied. HPV DNA, either type 16 or 18, was detected by polymerase chain reaction, and by Southern blot hybridization in all of the cell lines derived from cervical cancers. The hybridization patterns of HPV DNA after endonuclease digestion differed among cell lines, suggesting that all of these cell lines were independent isolates. Accordingly, high-risk types of HPV DNA seem to be ubiquitous in cervical cancer. HPV DNA was not detected in the cell lines derived from head and neck cancers or from any other malignancies besides cervical cancer in this study.</p

V-src genes in two cell lines of so-called RSV-transformed human cells are defective and inactive.

Trial of Rous sarcoma virus (RSV) induction by cell fusion with chick embryo cells (CEC) and wing web test from so-called RSV-transformed human cells, KC and RSb cells, was unsuccessful. The loss of RSV inducibility was also confirmed by DNA transfection method. Southern blot and northern blot hybridization of DNA and RNA from those cells with the v-src probe revealed that the v-src genes in those cells were defective and not expressed. On the other hand, the v-src gene in RSV-transformed mouse and rat cells was complete and transforming virus was inducible from them.&#60;/P&#62;</p

Effects of tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate on morphology and anchorage-independent growth of normal and established chick embryo cells.

The effects of 12-O-tetradecanoyl-phorbol-13-acetate (TPA) on the organization of cytoskeleton and growth of normal and established chick embryo cells (CEC) were studied. The cytoskeleton of normal CEC formed stress fibers, while that of the CEC lines established in our laboratory formed no stress fibers. TPA treatment of normal CEC resulted in disorganization of the stress fibers into amorphous structure, while that of the established CEC lines induced no reorganization of the cytoskeleton. TPA had no promotional effect in vitro or in vivo on tumor growth in normal or the established CEC.</p

Significance of IgG4-positive cells in severe eosinophilic chronic rhinosinusitis

Background: IgG4 production is regulated by type 2 (IL-4 and IL-13) and regulatory (IL-10) cytokines involved in the pathophysiology of chronic rhinosinusitis (CRS). We sought to determine the pathophysiological characteristics of IgG4-positive cells in sinonasal tissues in CRS, especially eosinophilic CRS (ECRS). Methods: IgG4-positive cells in uncinate tissues (UT) and nasal polyps (NP) were examined by immunohistochemistry. Associations between the number of IgG4-positive cells and clinicopathological factors were analyzed. Receiver operating characteristics (ROC) analysis was performed to determine the cut-off value of IgG4-positive cells in tissue that can predict the post-operative course. Results: IgG4 was mainly expressed in infiltrating plasma and plasmacytoid cells, and the number of IgG4-positive cells was significantly higher in NP, especially those from severe ECRS patients, than in UT. In CRS patients, the number of IgG4-positive cells significantly and positively correlated with blood and tissue eosinophilia, radiological severity, and serum level of total IgE. The number of infiltrating IgG4-positive cells was significantly higher in patients with a poor post-operative course (sustained sinus shadow 6 months after surgery) than in those with a good one. The number of IgG4-positive cells in NP could discriminate patients with a good or a poor post-operative course (area under the curve: 0.769). Also, 73.3% sensitivity and 82.5% specificity were achieved when the cut-off value was set at 17 cells/high-power field. Conclusions: Our results suggest that the local expression of IgG4 on cells may be used as a biomarker that reflects the pathophysiology of CRS, including the post-operative course