PubMed HealthSearch

PubMed · 6881762

Basic performance tests on the CERVIFIP linear array prescreener.

Abstract

CERVIFIP is a computer image-analysis prescreener for cervical cytology specimens. It is based on the Fast Interval Processor (FIP), a high-speed image analyzer, which uses a linear, charge-coupled, photodiode array scanner and a hardwired image data preprocessor unit for image data reduction prior to input to a computer. The software for CERVIFIP carries out real-time measurements and hierarchic classification of cells based on nuclear DNA content, morphologic and densitometric features for artifact rejection and operator review of cells suspected of being atypical. Preliminary tests have shown that the system is capable of accurate measurement of integrated optical density and positional information on cells at rates in excess of 30,000 cells per minute.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

J H Tucker, G Shippey. 1983. Basic performance tests on the CERVIFIP linear array prescreener.. https://pubmed.ncbi.nlm.nih.gov/6881762/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Decoding ALS from the tail end of RNA.

In this issue of Cell Genomics, McKeever et al.1 generate a single-nucleus transcriptomic atlas of ALS/FTLD brain and reveal widespread alternative polyadenylation changes. Their findings highlight 3' end RNA processing as a central integrator of stress responses, cell-type specificity, and disease susceptibility, offering new mechanistic insight and potential therapeutic directions.

Cell Nucleus

Lipopolysaccharide-induced interleukin-8 gene expression in human granulocytes: transcriptional inhibition by interferon-gamma.

We recently showed that lipopolysaccharide (LPS) is a potent inducer of interleukin-8 (IL-8) expression in human polymorphonuclear leucocytes (PMN), at the level of both mRNA and protein, and that interferon-gamma (IFN gamma) inhibits IL-8 mRNA accumulation in stimulated PMN. To further define the molecular basis of the regulation of IL-8 gene expression in PMN, we investigated the effects of LPS and IFN gamma at both the transcriptional and post-transcriptional levels. As determined by Northern blot analysis, new protein synthesis was not required for the induction of IL-8 mRNA expression by LPS. Neither did the half-life of IL-8 mRNA in LPS-treated PMN differ from that observed in untreated cells. However, nuclear run-on analysis revealed that LPS increased the transcription of the IL-8 and IL-1 beta genes and that, in LPS-activated cells, IFN gamma markedly inhibited the rate of IL-8 gene transcription, but not that of IL-1 beta. IFN gamma did not affect IL-8 mRNA stability in LPS-treated PMN, indicating that the cytokine does not regulate LPS-induced IL-8 gene expression through post-transcriptional events. These results provide the first evidence that human granulocytes can actively transcribe the IL-8 gene, and that transcriptional inhibition is the mechanism by which IFN gamma inhibits IL-8 gene expression in PMN.

Cell Nucleus

Cellular and molecular barriers to gene transfer by a cationic lipid.

Cationic lipids are widely used for gene transfer in vitro and show promise as a vector for in vivo gene therapy applications. However, there is limited understanding of the cellular and molecular mechanisms involved. We investigated the individual steps in cationic lipid-mediated gene transfer to cultured cell lines. We used DMRIE/DOPE (a 1:1 mixture of N-[1-(2,3-dimyristyloxy) propyl]-N,N-dimethyl-N-(2-hydroxyethyl)ammonium bromide (DMRIE) and dioleoyl phosphatidylethanolamine (DOPE) as a model lipid because of its efficacy and because it is being used for clinical trials in humans. The data show that cationic lipid-mediated gene transfer is an inefficient process. Part of the inefficiency may result from the fact that the population of lipid-DNA complexes was very heterogeneous, even under conditions that have been optimized to produce the best transfection. Inefficiency was not due to inability of the complex to enter the cells because most cells took up the DNA. However, in contrast to previous speculation, the results indicate that endocytosis was the major mechanism of entry. After endocytosis, the lipid-DNA aggregated into large perinuclear complexes, which often showed a highly ordered tubular structure. Although much of the DNA remained aggregated in a vesicular compartment, there was at least a small amount of DNA in the cytoplasm of most cells. That observation plus results from direct injection of DNA and lipid-DNA into the nucleus and cytoplasm indicate that movement of DNA from the cytoplasm to the nucleus may be one of the most important limitations to successful gene transfer. Finally, before transcription can occur, the data show that lipid and DNA must dissociate. These results provide new insights into the physical limitations to cationic lipid-mediated gene transfer and suggest that attention to specific steps in the cellular process may further improve the efficiency of transfection and increase its use in a number of applications.

Cell Nucleus