Search PubMed⌕ Search

Biomedical subjects

R Sperling

Publications and source records attributed to R Sperling.

86 records · Page 5Linked to original sources
PubMed1974

Self assembly of histone F2a1.

Purified F(2)a(1) histone molecules assemble into organized structures observable by electron microscopy. The basic structure observed at pH 8 and ionic strength of 0.15 has the shape of a bent rod with an average width of 22 A. The average circumferential length of the rod is 220 A and the average distance between the tips of the rod is 150 A. When the ionic strength is increased the rods align lengthwise into intertwined fiber-like structures. In some cases bent rods assemble "face-to-face" to give circular structures. At high protein concentrations the long fibers form paracrystalline arrays. Examination of these arrays by optical diffraction yielded a meridional reflection with a spacing of 150 A. The main additional reflections are compatible with a structure having a repeat unit of 300 A. We suggest that in chromatin the DNA is packed around organized periodic histone structures and that the periodicity of the histone structure may dictate the periodicity of the repeating unit in chromatin.

Centrifugation, Density Gradient↗
PubMedDate not supplied

Rofecoxib, a new cyclooxygenase 2 inhibitor, shows sustained efficacy, comparable with other nonsteroidal anti-inflammatory drugs: a 6-week and a 1-year trial in patients with osteoarthritis. Osteoarthritis Studies Group.

INTRODUCTION: Rofecoxib, a cyclooxygenase 2 inhibitor (sometimes known as a specific cyclooxygenase 2 inhibitor or Coxib), is used in osteoarthritis (OA). Published information indicates rofecoxib's improved gastrointestinal safety profile over nonselective nonsteroidal anti-inflammatory agents (NSAIDs). OBJECTIVE: To evaluate the efficacy and safety of rofecoxib in treating OA in 2 studies. METHODS: Two randomized, double-blind, parallel-group studies in patients with OA of the knee or hip were conducted using identical entry criteria and end points. A 6-week placebo-controlled trial in 736 patients compared 12.5 and 25 mg of rofecoxib once daily with 800 mg of ibuprofen 3 times daily, and a 1-year study compared 12.5 and 25 mg of rofecoxib once daily with 50 mg of diclofenac 3 times daily in 693 patients. RESULTS: Rofecoxib, at 12.5 and 25 mg, demonstrated efficacy clinically comparable with ibuprofen, assessed by 3 primary end points according to predefined comparability criteria. Both rofecoxib doses and ibuprofen provided significantly greater efficacy than placebo on all primary end points at 6 weeks. Both rofecoxib doses and diclofenac showed similar efficacy over 1 year. All treatments were well tolerated. CONCLUSIONS: Rofecoxib is effective in treating OA with once-daily dosing for 6 weeks and 1 year. Rofecoxib was generally safe and well-tolerated in OA patients for 6 weeks and 1 year. Arch Fam Med. 2000;9:1124-1134

Adult↗
PubMedDate not supplied

Juvenile dermatomyositis: serial studies of circulating autoantibodies to a 56kD nuclear protein.

In this study we report that circulating antibodies recognising a 56kD protein, which is a component of large nuclear ribonuclear particles, are commonly found in children with juvenile onset dermatomyositis (JDM). These autoantibodies, as detected by Western blotting, were present in over 90% (24/26) of sera from JDM patients, which exceeds the number of patients with adult onset myositis who express this antibody (up to 85%). In addition, they were not found in healthy controls. Serial bleeds taken during the course of the disease in eleven children with JDM enabled us to follow the titre of anti-56kD autoantibodies. Sera were also tested by indirect immunofluorescence for anti-nuclear antibodies (ANA) using Hep2 cells as substrate. These studies revealed two distinct patient groups: Group 1 with anti-56kD antibody positive and ANA positive; and Group 2 with anti-56kD antibody positive and ANA negative. In Group 1 there was some correlation between disease activity and anti-56kD levels which was absent among patients in Group 2.

Antibodies, Antinuclear↗