Right thoracic curvature in the normal spine

<p>Abstract</p> <p>Background</p> <p>Trunk asymmetry and vertebral rotation, at times observed in the normal spine, resemble the characteristics of adolescent idiopathic scoliosis (AIS). Right thoracic curvature has also been reported in the normal spine. If it is determined that the features of right thoracic side curvature in the normal spine are the same as those observed in AIS, these findings might provide a basis for elucidating the etiology of this condition. For this reason, we investigated right thoracic curvature in the normal spine.</p> <p>Methods</p> <p>For normal spinal measurements, 1,200 patients who underwent a posteroanterior chest radiographs were evaluated. These consisted of 400 children (ages 4-9), 400 adolescents (ages 10-19) and 400 adults (ages 20-29), with each group comprised of both genders. The exclusion criteria were obvious chest and spinal diseases. As side curvature is minimal in normal spines and the range at which curvature is measured is difficult to ascertain, first the typical curvature range in scoliosis patients was determined and then the Cobb angle in normal spines was measured using the same range as the scoliosis curve, from T5 to T12. Right thoracic curvature was given a positive value. The curve pattern was organized in each collective three groups: neutral (from -1 degree to 1 degree), right (> +1 degree), and left (< -1 degree).</p> <p>Results</p> <p>In child group, Cobb angle in left was 120, in neutral was 125 and in right was 155. In adolescent group, Cobb angle in left was 70, in neutral was 114 and in right was 216. In adult group, Cobb angle in left was 46, in neutral was 102 and in right was 252. The curvature pattern shifts to the right side in the adolescent group (p < 0.01) and in adult group (p < 0.001) compared to the child group. There was no significant difference in curvature pattern between adolescent and adult group.</p> <p>Conclusions</p> <p>Based on standing chest radiographic measurements, a right thoracic curvature was observed in normal spines after adolescence.</p

DNA Replication of Simian virus 40 chromatin in permeable CV-1 cells treated with lysolecithin.

Simian virus 40 (SV40) chromatin has a nucleosome structure similar to that of cellular chromatin and serves as a useful system for studying replication of cellular chromatin. A method for selectively permeabilizing African green monkey kidney cells (CV-1) with lysolecithin and DNA replication of SV40 chromatin in this permeable cell system are described. CV-1 cells treated with lysolecithin were markedly swollen but retained the basic morphology. This permeable cell system was successfully applied to the study of SV40 DNA synthesis as a single cell cycle event in CV-1 cells. SV40 DNA was synthesized with host polymerase α when supplied with appropriate substrates, which do not penetrate intact cells. Autoradiography of agarose gels indicated that replicating SV40 DNA completed replication in lysolecithin-treated permeable cells without the addition of cytosol. SV40 DNA of catenated dimers, both circules being nicked and gapped, were recovered from the agarose gel by freezing and squeezing gel slices