Biomedical subjects

E F Petricoin

Publications and source records attributed to E F Petricoin.

41 records · Page 3Linked to original sources

PubMed1991

Analysis of the lsi region involved in lipooligosaccharide biosynthesis in Neisseria gonorrhoeae.

The genetic locus (lsi-1) responsible for the transformation of the lipooligosaccharide (LOS)-defective Neisseria gonorrhoeae mutant FA5100 to LOS expression was studied by deletion mutagenesis and sequence analysis. An open reading frame that was preceded by a leader sequence containing regions with the potential to form hairpin loops was identified. A perfect sigma 70 promoter consensus sequence was found upstream from this open reading frame. Promoter function was screened for functionality by using lac fusion cassettes and in vitro transcription-translation analysis. A frameshift mutation in the lsi-1 gene was constructed by site-directed mutagenesis and introduced into the chromosome of FA19, the LOS-expressing isogenic parent strain of FA5100. The mutant was characterized by Southern blotting, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and Western blotting (immunoblotting) and found to be phenotypically identical to FA5100.

Amino Acid Sequence↗

PubMed1989

Molecular analysis of lipooligosaccharide biosynthesis in Neisseria gonorrhoeae.

A HindIII gene bank of Neisseria gonorrhoeae MUG116 was constructed in the cosmid vector pHC79. A cosmid (pSY81) was isolated that was able to convert N. gonorrhoeae FA5100 to reactivity with monoclonal antibody (MAb) 2-1-L8. Several MAb-reactive transformants were isolated and characterized with respect to lipooligosaccharide (LOS) production as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, their ability to react with two other LOS-specific MAbs (3F11 and O6B4), and Southern blot analysis. Escherichia coli containing the clone had altered lipopolysaccharide expression as determined by electrophoretic analysis; however, no reactivity was seen with gonococcus-specific MAbs. The introduction of pSY81 into FA5100 had a pleiomorphic effect, giving rise to transformants having the full parental phenotype or transformants lacking reactivity to a combination of LOS-specific MAbs. Southern blot analysis indicated that the LOS biosynthetic mutation in FA5100 was not due to chromosomal rearrangement or large deletions.

Blotting, Southern↗

PubMed1988

Use of transformation to construct Neisseria gonorrhoeae strains with altered lipooligosaccharides.

DNA isolated from a nalidixic acid- and rifampin-resistant derivative of Neisseria gonorrhoeae serum-resistant strain 302 (MUG116), a strain that reacts with monoclonal antibody (MAb) 2-1-L8, was used to transform N. gonorrhoeae DOV, a serum-sensitive strain, to antibiotic resistance and/or reactivity with the MAb. MAb 2-1-L8 binds to a 3.6-kilodalton lipooligosaccharide (LOS). Reactivity with MAb 2-1-L8 transformed as a single marker and was unlinked to either of the antibiotic resistance markers. Immunoblot analysis of LOSs separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that new LOSs were synthesized in the transformed cells and that these LOSs corresponded to those of the DNA donor. Although multiple LOS components were made by the transformants, the MAb recognized only one. All transformants that were selected for on the basis of strong reactivity with MAb 2-1-L8 were serum resistant; however, the level of resistance correlated with the apparent loss of recipient LOS components. MAb 2-1-L8-reactive transformants that still produced DOV LOS components remained serum sensitive.

Blood Bactericidal Activity↗

PubMedDate not supplied

The role of tissue microdissection in cancer research.

Tissue microdissection is a laboratory method that is used to procure specific cells or cell populations from a histology slide under direct microscopic visualization. The recovered cells can be studied with a variety of DNA, messenger RNA, and protein analysis methods, including new high-throughput gene expression and proteomics technologies. This approach is permitting investigators to comprehensivelyexamine the molecular anatomy of cells in tissue sections forthe first time. This article reviews the development and evolution of tissue microdissection techniques, summarizes examples of research studies, and discusses related challenges that the research community must address. Additional information and complete laboratory protocols are available on a website at http://cgap-mf.nih.gov/.

DNA, Neoplasm↗

PubMedDate not supplied

Cancer proteomics: from biomarker discovery to signal pathway profiling.

In the post-genomic era of science, the field of proteomics promises the discovery of new molecular targets for therapy, biomarkers for early detection, and new endpoints for therapeutic efficacy and toxicity. Patient-specific targeted therapeutics with reduced toxicity and increased efficacy, the ultimate goal for rational drug development, can only be achieved if direct analyses of the tissue cells in the actual human malignancy are analyzed. To that end, technologies such as Laser Capture Microdissection (LCM), is providing unparalleled access to the purified diseased human cells directly from tissue specimens. However, limited availability of patient material is a challenge towards the development of new highly sensitive proteomic methodologies. Two-dimensional gel electrophoresis (2D-PAGE), still the mainstay of most proteomic analysis of disease, is being complemented, and in some instances replaced by new exciting approaches to multiparametric protein characterization. The use of rapid, high throughput mass spectrometric-based fingerprints of peptides and proteins may prove to be valuable for new molecular classification of human tumors and disease stages. Coupled with LCM, high-density protein arrays, antibody arrays, and small molecular arrays, could have a substantial impact on proteomic profiling of human malignancies. Finally, detailed real-time knowledge about the states of intracellular signaling circuitry and pathways in the normal and malignant cells before, during and after therapy will yield invaluable information about mechanism of action and efficacy of existing and novel therapeutics for the treatment of human cancer.

Biomarkers↗