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Biomedical subjects

A R Ricci

Publications and source records attributed to A R Ricci.

6 recordsLinked to original sources
PubMed1986

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↗
PubMed1984

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↗
PubMed1976

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↗
PubMedDate not supplied

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↗
PubMedDate not supplied

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↗