PubMed Health⌕ Search

Biomedical subjects

J Abbate

Publications and source records attributed to J Abbate.

8 recordsLinked to original sources
PubMed2001

Bifunctional protein conferring enhanced green fluorescence and puromycin resistance.

A new genetic marker was created in which sequences from enhanced green fluorescent protein were fused to those of puromycin N-acetyl transferase. The resulting fusion protein (EGFP-puro) conferred both green fluorescence and resistance to puromycin when expressed in mammalian cells. The utility of EGFP-puro as a selectable/screenable marker was demonstrated by the ease with which a recombinant guinea pig cytomegalovirus containing EGFP-puro was isolated by a combination of puromycin selection and screening for green fluorescence. We conclude that EGFP-puro is a compact and versatile marker that should prove useful for recombinant virus and transgenic cell line construction, particularly in applications in which coding capacity is limited.

Animals↗
PubMed1979

Identification of tertiary base pair resonances in the nuclear magnetic resonance spectra of transfer ribonucleic acid.

The low-field hydrogen-bond ring NH proton nuclear magnetic resonance (NMR) spectra of several transfer ribonucleic acids (tRNAs) related to yeast tRNAPhe have been examined in detail. Several resonances are sensitive to magnesium ion and temperature, suggesting that they are derived from tertiary base pairs. These same resonances cannot be attributed to cloverleaf base pairs as shown by experimental assignment and ring current shift calculation of the secondary base pair resonances. The crystal structure of yeast tRNAPhe reveals at least six tertiary base pairs involving ring NH hydrogen bonds, which we conclude are responsible for the extra resonances observed in the low-field NMR spectrum. In several tRNAs with the same tertiary folding potential and dihydrouridine helix sequence as yeast tRNAPhe, the extra resonances from tertiary base pairs are observed at the same position in the spectrum.

Arginine↗
PubMed1977

High-resolution nuclear magnetic resonance determination of transfer RNA tertiary base pairs in solution. 1. Species containing a small variable loop.

Eight class I tRNA species have been purified to homogeneity and their proton nuclear magnetic resonance (NMR) spectra in the low-field region (-11 to -15 ppm) have been studied at 360 MHz. The low-field spectra contain only one low-field resonance from each base pair (the ring NH hydrogen bond) and hence directly monitor the number of long-lived secondary and tertiary base pairs in solution. The tRNA species were chosen on the basis of their sequence homology with yeast phenylalanine tRNA in the regions which form tertiary base pairs in the crystal structure of this tRNA. All of the spectra show 26 or 27 low-field resonances approximately 7 of which are derived from tertiary base pairs. These results are contrary to previous claims that the NMR spectra indicate the presence of resonances from secondary base pairs only, as well as more recent claims of only 1-3 tertiary resonances, but are in good agreement with the number of tertiary base pairs expected in solution based on the crystal structure. The tertiary base pair resonances are stable up to at least 46 degrees C. Removal of magnesium ions causes structural changes in the tRNA but does not result in the loss of any secondary or tertiary base pairs.

Binding Sites↗
PubMed1976

Immune evaluation of lung cancer patients undergoing radiation therapy.

Immunocompetence, as determined by skin reactivity to five microbial antigens, dinitrochlorobenzene (DNCB), and percent and absolute number of total T and B rosette-forming cells (RFC), was assessed before and up to 180 days after radiotherapy in 29 patients with carcinoma of the lung. Pretherapy evaluation showed a depressed response to microbial antigens (only 38% positive), to DNCB (50% positive), and lower level of T-RFC. Postradiotherapy determinations were further depressed. Patients with positive pretherapy responses to microbial antigens and DNCB and higher than median absolute numbers at total T-RFC had significantly longer survival. These data suggest that pretherapy immune evaluation is a good prognostic indicator. No prognostic significance was found in B-RFC evaluation. No correlation was seen between the stage of disease (locally advanced or with distant metastases) and the pretherapy immune response.

Adenocarcinoma↗
PubMed1976

Serial studies of immunocompetence in head and neck cancer patients undergoing radiation therapy.

Studies of the immunocompetence of patients undergoing radiation therapy were carried out before and after treatment. The immunological evaluation is a valuable prognostic tool for patients with squamous cell carcinomas of the head and neck. The degree of immunoresponsiveness is not related to the stage of the primary tumor, but it definitely correlates with the extent of lymph node involvemnt. This evaluation may permit identification of those cases for which immunotherapy is indicated.

Adult↗