Biomedical subjects

J Bednar

Publications and source records attributed to J Bednar.

23 records · Page 2Linked to original sources

PubMed1990

Clinical and pathologic studies of twenty-six patients with penetrating foreign body injury to the joints, bursae, and tendon sheaths.

Foreign body synovitis has been neglected in the rheumatology literature. We describe 26 patients in whom arthritis, bursitis, or tenosynovitis appeared within 1 day to 7 years after an initial injury by a penetrating foreign body. Twenty-two patients presented with acute synovitis, which was followed by chronic or recurrent inflammation mimicking septic arthritis, osteomyelitis, monarticular juvenile rheumatoid arthritis, bone tumor, or apatite deposition disease. Foreign bodies were not seen in 5 inflammatory synovial fluids studied, but were seen in the synovium or periarticular tissues of 17 patients. Excisional biopsy was required in most patients for precise diagnosis and treatment.

Adolescent↗

PubMed1990

TMJ imaging.

Explore the source record for details and available documents.

Arthrography↗

PubMed1989

The effects of demineralized bone matrix and direct current on an "in vivo" culture of bone marrow cells.

Bone marrow cells (BMCs) from rabbit femora and tibiae were grown in diffusion chambers implanted in rabbit muscle. At 42 days 80% of the BMC chambers exhibited cartilage formation within them. Demineralized bone matrix added to the marrow cell suspension in the chamber accelerated the appearance and increased the number of chambers with cartilage. Mineralization of the cartilage also occurred earlier in the chambers with bone matrix. In a second experiment, a 5-microA direct current cathode in the bone marrow chamber increased the number of chambers containing cartilage from 50 to 80% at day 25. Mineralization also occurred earlier in the chambers with direct current.

Animals↗

PubMed1986

Gentamicin-induced ototoxicity complicating treatment of chronic osteomyelitis.

Ototoxicity, though a significant disabling complication of aminoglycoside antibiotic therapy, is monitored infrequently. Chronic osteomyelitis patients treated with an aminoglycoside are in a group at higher risk due to the length of therapy and large total dose of drug required for treatment. Serum levels of gentamicin should be maintained within therapeutic ranges but below toxic levels. Gentamicin ototoxicity is vestibular in two thirds of patients and cochlear in one third. One half of the patients with cochlear toxicity also have vestibular symptoms. Symptoms are often vague, insidious in onset, and masked by the critical presentation of the primary infectious process. Symptoms may occur immediately upon initiation of therapy, any time during the course of treatment, or after administration has been completed. The development of toxicity should be monitored on a regular basis by specifically asking the patient whether there has been any subjective hearing loss, ear fullness, tinnitus, or vertigo supplemented by pretreatment and follow-up audiogram and electronystagmogram (ENG). Therapy should be discontinued at the first sign of alteration of cochlear or vestibular function. Ototoxic recovery occurs in only about 50% of the patients affected.

Adult↗

PubMedDate not supplied

DNA at the entry-exit of the nucleosome observed by cryoelectron microscopy.

Whereas the DNA path inside the nucleosome is well established, it is essentially unknown in the "entry-exit" region, a missing piece in our understanding of the chromatin fiber's folding. The three-dimensional structure of "linker" DNA was investigated here on single nucleosomes reconstituted without H1 on a 256-bp DNA fragment. Cryoelectron microscopy and three-dimensional reconstruction of the DNA axis reveal these nucleosomes as 1.61 +/- 0.15 left-handed superhelical turn particles whose DNA arms bend away from the core particle, thus preventing the occurrence of a crossing in the entry-exit region.

Animals↗