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Biomedical subjects

A D Goren

Publications and source records attributed to A D Goren.

18 recordsLinked to original sources
PubMed2000

Updated quality assurance self-assessment exercise in intraoral and panoramic radiography. American Academy of Oral and Maxillofacial Radiology, Radiology Practice Committee.

This updated self-assessment exercise for the dental team by the Radiology Practice Committee of the American Academy of Oral and Maxillofacial Radiology is intended to produce the highest quality diagnostic radiographs while keeping patient exposure as low as is reasonably achievable. To continue to provide the best radiographic services to patients, those involved in dental radiography need to be aware of the latest changes and advances in dental radiography and need to use them in their practice.

Credentialing↗
PubMed1999

Causes of excessive bitewing exposure: results of a survey regarding radiographic equipment in New York.

OBJECTIVE: The purpose of this study was to identify the causes of excessive exposure in those dental practices that were found to use exceptionably high levels of radiation in bitewing radiography. STUDY DESIGN: Using the parameters of the Dental Exposure Normalization Technique survey, certified radiation equipment safety officers conducted on-site inspections of 186 intraoral x-ray machines in 77 dental facilities. RESULTS: In 23 facilities, the safety officers identified 43 units (23.1%) that delivered entrance exposures greater than 10% in excess of the upper limit of recommended exposures. For each of 27 (63%) of these units, the cause of the elevated exposure was clearly identifiable. CONCLUSIONS: The factors contributing to increased exposure, listed from most frequent to least frequent, were as follows: improper processing, kilovoltage miscalibration, use of D-speed techniques with E-speed film, use of newly installed units with default timer settings that were too high, exposure timer failure, and insufficient half-value layer. Only 18% of the facilities surveyed reported using E-speed film.

Child↗
PubMed1997

Processor quality assurance using digital imaging.

The purpose of this study was to develop and test a computer imaging method for assessing longitudinal processor variability. A technique called adaptive histogram equalization was used to test deviation in automatic processing when a test film is compared with a time-temperature processed standard at two different kVp's and film speeds. In a 14-day study we found that the density ranges for the standard film did not change, while the density range of the automatically processed films changed by a factor of two. These results suggest that if automatic processing is to be used for films taken as part of a longitudinal study-for example, subtraction-then processor variation can potentially lead to incorrect inference of bone gain or loss.

Absorptiometry, Photon↗
PubMed1989

Survey of radiologic practices among dental practitioners.

The purpose of this study was to determine the factors that influence and contribute to patient exposure in radiologic procedures performed in the offices of 132 staff members within the dental department of a teaching hospital. A questionnaire was prepared in which data were requested on brands of film used, type of x-ray unit used, processing, and use of leaded apron, cervical shield, and film holder. Offices were also visited to evaluate performance of existing dental x-ray equipment. Both the Dental Radiographic Normalizing and Monitoring Device and the Dental Quality Control Test Tool were evaluated. The average exposure was equivalent to the class D film (220 mR), but only 13% of those surveyed used the faster class E film, which would reduce patient exposure in half. The survey indicates that dentists are not using the newer low-exposure class E film in their practices.

Attitude of Health Personnel↗
PubMed1987

Effect of beta-amino-propionitrile on the regenerating newt limb evaluated by uptake of 3H-proline and 3H-lysine.

Newt forelimbs were unilaterally amputated and Beta-amino propionitrile (BAPN) was added to the water in which the newts were maintained. Sixty-three days after amputation, animals were injected with either 3H-proline or 3H-lysine. Forelimbs distal to the elbow of both amputated and non-amputated sides were removed 72 hours later. Uptake of 3H-proline and 3H-lysine in whole limbs was assessed by liquid scintillation and in cartilage cells and matrix by autoradiography. Amputation was a potent stimulus to both collagen formation and maturation during regeneration. BAPN reduced the stimulatory effect of amputation on collagen formation but not on its maturation. Collagen synthesis and maturation are independent events and, in intact non-regenerating limbs, BAPN adversely affected collagen maturation while collagen synthesis was unaltered.

Aminopropionitrile↗
PubMed1983

Autoradiographic and liquid scintillation assessment of beta-amino-propionitrile-induced inhibition of collagen maturation using 3H-proline and 3H-lysine.

BAPN (0.1 mg/day) was injected into chick embryos for 4 days starting on the 7th day of incubation. On the 11th day, the embryos were administered either 3H-proline or 3H-lysine. 36 h later, the incorporation of each isotope by the periosteal osteogenic cells as well as into bone matrix was investigated by autoradiography. The incorporation of the two isotopes into whole bones was assessed by liquid scintillation counting. 3H-proline incorporation into the cellular or matrical compartments was unaffected by treatment. As compared to the controls, 3H-lysine label in BAPN-treated embryonic bones was significantly higher in the cellular compartment but was reduced over the bone matrix. The data provide the first direct morphological evidence that BAPN probably induces certain changes in the maturation of collagen involving lysyl residues which result in an inhibition of cross-linkage formation in collagen.

Aminopropionitrile↗