Exonuclease III as a probe of chromatin structure in vivo.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
A R Ricci
Publications and source records attributed to A R Ricci.
Cloning and development expression of Choristoneura hormone receptor 75: a homologue of the Drosophila E75A gene.
Cloning and characterization of a cDNA of the spruce budworm, Choristoneura fumiferana, that showed high amino acid similarity with the deduced amino acid sequences of E75 cDNAs cloned from Manduca sexta, Galleria melonella, and Drosophila melanogaster are described. Initially, a cDNA fragment and then a full length cDNA were cloned from C. fumiferana. The longest open reading frame of this cDNA had 690 codons and its deduced amino acid sequence had all five domains typical of a steroid hormone nuclear receptor. The deduced amino acid sequence of this cDNA showed the highest identity with the deduced amino acid sequence of E75A cDNAs cloned from M. sexta, G. melonella, and D. melanogaster, and is therefore named Choristoneura hormone receptor 75A (CHR75A). The CHR75A cDNA probe detected a 2.6 kb mRNA that was abundant at the time of the ecdysteroid peaks during molting in the embryonic, larval and pupal stages. In the sixth instar larvae, CHR75 mRNA was detected in the epidermis, fat body and midgut, and maximum expression was observed during the prepupal peak of ecdysteroids in the hemolymph. CHR75 mRNA was induced in ecdysone treated CF-203 cells and in the midgut, fat body and epidermis of larvae that were fed the non-steroidal ecdysteroid agonist, RH-5992. In vitro transcription and translation of the CHR75A cDNA yielded a 79 kDa protein that bound to the retinoic acid receptor related orphan receptor response element (RORE).
Amino Acid Sequence↗
An automated high pressure reaction vessel for routine preparation of short-lived radiopharmaceuticals.
A remote, automated high-pressure/temperature system for preparation of radiopharmaceuticals is described. The system was routinely employed in our laboratories in the production of multimillicurie amounts of 11C labeled D,L-amino acids in more than 90 production runs, with typical final D,L-product activities of 240-400 mCi. The high pressure system, however, is not restricted only to the production of 11C labeled amino acids, but for application in any synthetic procedure requiring high pressure (approximately 300 psia) and temperature (greater than 300 degrees C).
Carbon Radioisotopes↗
Prospects for both precision and accuracy in positron emission tomography.
Reproducibility or precision was measured for a current positron emission tomographic (PET) system and was simulated by both computer and experimental methods for potential future systems. The present and potential future precision of PET systems is on the order of 1 to 2% for equilibrium studies (such as fluorodeoxyglucose metabolism measurements) with a few million counts per image, and better than 10% for dynamic studies with a few hundred thousand counts per image. To take advantage of this high precision, the instrumental accuracy of PET systems should match or better the precision of the measurements. The major sources of inaccuracy in PET, outside of deficiencies in electronic or computer hardware and software, are poor resolution, nonuniform resolution, and scatter. The use of narrow bismuth germanate detectors, adequately large detector ring diameters, and properly designed interplane septa will provide substantial improvements in all of these deficiencies.
Brain↗
The Mark IV system for radionuclide computed tomography of the brain.
The Mark IV scanning system is a simple four-sided arrangement of 32 independent detectors which rotate continously as a unit, detecting, processing, and displaying the reconstructed data while the study progresses. Detection is by single photon counting and is compatible with commercially available radionuclides. An empirical correction is applied for attenuation, difference in detector response, and scatter. It is a high-sensitivity device with approximately uniform resolution throughout the section plane. There is good reproducibility and accuracy for absolute quantification of radionuclide concentration in the brain. Clinical applications include scans of 99mTcO4, 99mTc-RBC, 123I-iodoantipyrine, 99mTc-diphosphonate, and 111In-DTPA.
Adolescent↗
Quantitative section scanning using orthogonal tangent correction.
Explore the source record for details and available documents.
Adult↗
The effect of chlorpheniramine on asthma.
Patients with stable asthma can tolerate antihistamines without any significant deleterious effects both on a short- and a long-term basis. In addition, patients with steroid-dependent asthma appear to tolerate antihistamines without any significant deleterious effects. Therefore, oral chlorpheniramine does not appear to have ill effects on patients with asthma. Warning labels required by the FDA for antihistamine use in asthmatics are unnecessary.
Adult↗
Delayed nasal mucociliary clearance in patients with nonallergic rhinitis and nasal eosinophilia.
This study investigated nasal mucociliary clearance as related to nasal eosinophilia in nonallergic rhinitis patients using the technique of nasal saccharin challenge. Fifty-six consecutive patients with nonallergic rhinitis were evaluated with nasal cytology and saccharin challenge. A saccharin challenge time of greater than 25 minutes was considered abnormal. Twelve of 56 patients (21.4%) had nasal eosinophilia. Fifteen of 56 patients (26.8%) had prolonged nasal circulation times greater than 25 minutes, indicating delayed mucociliary clearance. Although 7 of 12 patients (58.3%) with nasal eosinophilia had delayed mucociliary clearance, only 8 of 44 patients (18.2%) without eosinophilia had circulation times longer than 25 minutes. The correlation of nasal eosinophilia with prolongation of the nasal circulation time is statistically significant (chi square 5.84, P = .0156). We postulate that damage to the nasal mucociliary system may be an etiologic factor for a subset of patients with nonallergic rhinitis and that this damage may be mediated by eosinophils.
Adult↗