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Biomedical subjects

R M Bernstein

Publications and source records attributed to R M Bernstein.

137 records · Page 8Linked to original sources
PubMedDate not supplied

Myositis autoantibody inhibits histidyl-tRNA synthetase: a model for autoimmunity.

In autoimmune disorders such as rheumatoid arthritis and systemic lupus erythematosus (SLE), autoantibodies are generated against a variety of macromolecules. Myositis is a human autoimmune disease characterized by weakness and wasting of muscle. In American studies, antibodies directed against soluble cellular constituents were detected by immunodiffusion in about 60% of cases; the commonest of these, found in 25% of patients, was antibody to the Jo-1 antigen. An antibody system referred to as PL-1 was recognized at a similar frequency in a series of patients studied at Hammersmith Hospital, London. We show here that this system is identical with the Jo-1 system and demonstrate that the antigen is a polypeptide of molecular weight (Mr) 50,000. The protein is immunoprecipitated with tRNA His and appears to be histidyl-tRNA synthetase. The identity of the Jo-1 antigen, the first of the RNA-associated antigens familiar in autoimmune disease to be characterized as a specific enzyme, suggests a model for virus involvement in autoantibody generation.

Amino Acyl-tRNA Synthetases↗
PubMedDate not supplied

Identity of the proliferating cell nuclear antigen and cyclin.

Studies of growth regulation and cellular transformation will be assisted by the identification of proteins that are preferentially synthesized in dividing cells. The 'proliferating cell nuclear antigen' ( PCNA ), distinguished by its apparent association with cell division, is defined by reaction with an antibody found in the autoimmune disease systemic lupus erythematosus (SLE). This antibody reacts with proliferating cells including tumour cells but gives weak or undetectable immunofluorescence with resting cells of normal tissues. Peripheral blood lymphocytes are devoid of PCNA until activated by mitogen in vitro. In synchronized cultures its level and distribution fluctuate through the cell cycle, with a striking accumulation in the nucleolus late in the G1 phase and early in the S phase. Many of these properties are shared by ' cyclin '. This nuclear protein, identified by its position in a two-dimensional separation of cell proteins, is also transformation-sensitive and is preferentially synthesized in the S phase. We establish here that PCNA and cyclin are identical, and show that PCNA is an acidic nuclear protein of apparent molecular weight 35,000.

Animals↗
PubMedDate not supplied

Nonunion of a Hoffa fracture in a child.

The authors report a case of a Hoffa fracture of the lateral femoral condyle that subsequently went on to nonunion in an eight-year-old child. The child presented with symptoms of knee pain and snapping five years after a motor vehicle accident. The nonunion fragment involved most of the lateral femoral condylar articular surface but spared the physis. After treatment by open reduction and limited internal fixation, the nonunion has healed, and the child has virtually full range of motion of the knee and no evidence of growth disturbance.

Bone Screws↗
PubMedDate not supplied

Rod diameter prediction in patients with osteogenesis imperfecta undergoing primary osteotomy.

SUMMARY: Because the cross-sectional shape of the long bones of patients with osteogenesis imperfecta is often elliptical, the use of preoperative radiographs to determine intramedullary rod diameter in these patients undergoing osteotomy may be misleading. To investigate this, the authors correlated the narrowest inner bone diameter (NID) on preoperative radiographs to the rod diameter (RD) on postoperative radiographs. The authors evaluated 79 bones in 27 patients undergoing primary osteotomy with intramedullary fixation. Only 5% of the bones had an equal NID and RD, with 81% of bones having a smaller RD than the measured NID. Although a positive correlation was found between RD and NID (correlation coefficient 0.76), measurement of the NID on preoperative radiographs did not provide a good prediction of the actual RD used in this series of children with osteogenesis imperfecta.

Adolescent↗