Biomedical subjects

H Freed

Publications and source records attributed to H Freed.

13 recordsLinked to original sources

PubMed1992

Diagnostic efficacy of digitized images vs plain films: a study of the joints of the fingers.

Four hundred fifteen finger joints from 30 patients were evaluated for the presence of joint-space erosion, narrowing, and degenerative spurring on plain films, low-resolution digitized images (1024 x 840 bytes x 12 bit matrix), and high-resolution digitized images (2048 x 1680 bytes x 12 bit matrix). Three hundred four joints were abnormal. Low- and high-resolution digital images were displayed on a 1K x 1K monitor with the ability to change level, window, orientation, and brightness. Five radiologists interpreted images. The presence or absence of each abnormality was determined by consensus of two skeletal radiologists who did not otherwise participate in the study. Receiver-operating-characteristic analysis was used to obtain an area and a true-positive rate at a 0.10 false-positive rate for each interpreter. Randomized block analysis of variance with interpreters as blocks was used to compare areas and true-positive rates among imaging techniques for each type of abnormality; no statistically significant differences were found. In conclusion, the efficacy of display of digitized images on high- and low-resolution modes is not significantly different from that of plain films in the detection of erosions, joint-space narrowing, or degenerative spurring in small joints of the hands.

Analysis of Variance↗

PubMed1990

Total knee replacement: radiologic findings in failure of porous-coated metal-backed patellar component.

One technique for replacing the articular surface of the patella in total knee replacement is the use of a cementless porous-coated metal-backed polyethylene component. Anteroposterior, lateral, and Merchant or skyline radiographs in 10 cases of porous-coated metal-backed components that failed were evaluated for component alignment, component displacement, radiolucencies, loose beads, and integrity of the patellar component. Component failure was documented by surgery in all 10 cases. Seven cases of failure involved the patellar pegs or junction of the pegs with the metal backing and three cases involved the polyethylene portion. In the seven cases of peg-metal backing failure, three cases showed loose beads before failure and seven cases showed displacement of the metal backing at time of failure. All three cases of polyethylene failure showed narrowing or displacement of the polyethylene portion. Our experience shows that displacement of the metal backing, displacement of the polyethylene, and disruption of patellar pegs are seen in failed porous-coated metal-backed patellar components. Loose beads may be seen before peg-metal backing failure.

Humans↗

PubMed1989

Special diagnostic procedures in sports medicine.

In summary, there are a number of imaging procedures available to support the physician in his or her evaluation of sports injuries. Conventional radiographs remain the primary imaging examination. Specialized radiographic projections will often provide additional pertinent information. A fluoroscopic examination or conventional tomography may provide a cost-effective method of clarifying subtle post-traumatic changes. The use of the more sophisticated and costly imaging procedures should be reserved for those cases in which a diagnosis cannot be made with simpler technology. CT scanning, by virtue of its ability to image in the axial plane, has proved to be an effective method of documenting injuries particularly in complex bony anatomy such as the spine, wrist, elbow, and hips. CT arthrography provides diagnostic information about intra-articular structures. MRI is emerging as an excellent method of noninvasively imaging injuries to soft-tissue structures such as tendons, ligaments, and cartilage. The advancements in MRI technology that are projected for the future may expand the range of usefulness of this modality and decrease the current high cost of these procedures. Radionuclide scanning with Tc99m diphosphonate compounds has proved to be an efficient method of localizing subtle bone pathology and providing a "road map" for further analysis with additional imaging techniques. The cost-effective use of all of these imaging procedures is predicated on an understanding of their usefulness in the diagnosis of each clinical problem and the judicious use of each procedure to fit the needs of the individual patient.

Athletic Injuries↗

PubMed1979

Maintenance of adult rat hepatocytes on C3H/10T1/2 cells.

A procedure is described for maintaining primary cultures of adult rat hepatocytes on a layer of irradiated C3H/10T1/2 cells. These hepatocytes were capable of metabolizing the liver carcinogen N-2-acetylaminofluorene to water-soluble products and after 14 days in culture could still metabolize approximately 70% of the Day 1 level. Hepatocytes maintained on the C3H/10T1/2 cells were inducible for the liver-specific enzyme tyrosine aminotransferase, and exhibited approximately a 4-fold induction by hydrocortisone during a 10-day culture period. Morphologically, these hepatocytes retained many characteristics of hepatocytes in vivo. By contrast, hepatocytes maintained on plastic lost both N-2-acetylaminofluorene-metabolizing ability and tyrosine aminotransferase activity by Day 5. This was presumably due to degeneration of the hepatocytes and an overgrowth by fibroblasts. The maintenance of morphologically and biochemically functional hepatocytes in culture on feeder cells may provide a valuable approach for studying drug metabolism and liver cell transformation in vitro.

2-Acetylaminofluorene↗

PubMed1979

Developmental imperatives in the latter half of life: some clinical implications.

In the latter half of life men tend to shift from active to passive mastery, women the opposite. Four cases are described clinically and are discussed from the point of view of this thesis.

Adaptation, Psychological↗

PubMed1970