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Biomedical subjects

R B Hoffman

Publications and source records attributed to R B Hoffman.

At least 19 recordsLinked to original sources
PubMed1991

Anti-kickback rules place physicians in unsettled waters.

The Resource-based Relative value scale, RBRVS, the sweeping reform in how physicians will be paid, is not the only change being made in Medicare. The federal government has just issued new rules and a new "Fraud Alert" interpreting Medicare's anti-kickback statute, focusing on the business relationships between medical providers and suppliers.

Conflict of Interest↗
PubMed1989

Coronary artery bypass grafts: new universal markers.

This report describes a new system to facilitate the identification of coronary artery bypass grafts during repeat coronary angiography. Geometric markers (square, triangle, circle, hexagon) are placed over the aortic end of the graft, with each geometric shape designating the target vessel of the graft, e.g. square, right coronary; triangle, anterior descending. This system significantly simplifies cannulation of the postoperative patient and also allows immediate recognition of specific vessels bypassed by mere perusal of the chest film.

Angiography↗
PubMed1980

Piracetam and fish orientation during parabolic aircraft flight.

Goldfish were flown in parabolic Keplerian trajectories in a KC-135 aircraft to assay both the effectiveness of piracetam as an anti-motion sickness drug and the effectiveness of state-dependent training during periods of oscillating gravity levels. Single-frame analyses of infrared films were performed for two classes of responses--roll rates in hypogravity or hypogravity orienting responses (LGR) and climbing responses in hypergravity or hypergravity orienting responses (HGR). In Experiment I, preflight training with a vestibular stressor facilitated suppression of LGR by the 10th parabola. An inverse correlation was found between the magnitudes of LGR and HGR. Piracetam was not effective in a state-dependent design, but the drug did significantly increase HGR when injected into trained fish shortly before flight. In Experiment II, injections of saline, piracetam, and modifiers of gamma-aminobutyric acid (GABA)--aminooxyacetic acid (AOAA) and isonicotinic acid (INH)--did not modify LGR. AOAA did significantly increase HGR. Thus, the preflight training had a beneficial effect in reducing disorientation in the fish in weightlessness, but the drugs employed were ineffective.

Aminooxyacetic Acid↗
PubMed1978

Computed tomography diagnosis of renal angiomyolipoma.

Angiomyolipomas with a high fat content can be diagnosed by CT, thus eliminating the need for angiography. Surgery can then be tailored for maximal renal tissue preservation. One unilateral and two bilateral surgically confirmed cases of renal angiomyolipoma are presented with a typical fourth case in which surgery was cancelled based on the pathognomonic CT findings.

Adult↗
PubMed1978

Effect of prehatching weightlessness on adult fish behavior in dynamic environments.

At 16-17 months of age, three groups of fish from the embryonated eggs in the ASTP killifish experiment were subjected to postflight tests consisting of rapidly changing environments. It was found that the group of fish with the least amount of development at orbital insertion (A-32) had a decreased rheotropism for both the moving background and the rotating water current tests when compared to ground control fish. Exposure to parabolic aircraft flight conditions revealed that the A-32 fish were less disoriented during zero gravity periods and were hypersensitive to high-gravity periods. These results suggested a modified vestibular competency due to a 9-d prehatching weightlessness exposure.

Adaptation, Physiological↗
PubMed1977

Behavioral analyses of killifish exposed to weightlessness in the Apollo-Soyuz test project.

Two groups of killifish, Fundulus heteroclitus, which were flown aboard Apollo-Soyuz, were subjected to postflight behavioral testing. The first group examined consisted of a graded series of embryos representing key developmental stages at orbital insertion (32-h, 66-h, and 128-h stages; pre-liftoff fertilization times). The tests revealed that the young adults from the flight 32-h stage had a significantly decreased positive geotaxis and increased negative phototaxis when compared with ground controls. These findings suggested a greater sensitization of the least-developed flight stage to post-hatching environmental influences. The second group consisted of 21-d old juveniles which were subjected to light orientation tests soon after recovery. No significant differences were detected.

Animals↗
PubMed1975

Abdominal cystic lymphangiomatosis: report of a case involving the liver and spleen and illustration of two cases with origin in the greater omentum and root of the mesentery.

B-scan ultrasonic examination of a 10-year-old Mexican-American female with multiple avascular hepatic and splenic defects on both isotopic and angiographic evaluation revealed numerous cystic lesions, a few of which contained numerous internal echoes. Subsequent pathological examination revealed lymphangiomatosis of the liver and spleen. Some of the cysts contained caseous material as predicted only by the ultrasonic examination. Cystic lymphangiomatosis of the spleen is a rare condition and only a few cases of involvement of both the spleen and liver have reported. This is the first such case evaluated by ultrasound. Two cases are also illustrated of cystic lymphangiomatosis with origin in the greater omentum and root of the mesentery.

Adolescent↗