Human Cu/Zn superoxide dismutase gene family: molecular structure and characterization of four Cu/Zn superoxide dismutase-related pseudogenes.

Four distinct human Cu/Zn superoxide dismutase (SOD1; EC 1.15.1.

In vitro expression of human p53 cDNA clones and characterization of the cloned human p53 gene.

The human p53 gene was cloned and characterized by using a battery of p53 DNA clones. A series of human cDNA clones of various sizes and relative localizations to the mRNA molecule were isolated by using the human p53-H14 (2.35-kilobase) cDNA probe which we previously cloned.

Linear simian virus 40 DNA fragments exhibit a propensity for rolling-circle replication.

A linear simian virus 40 origin-containing DNA fragment replicated in monkey COS cells, generating tandemly repeated (head-to-tail) structures. Electron microscopy revealed circle-and-tail configurations characteristic of rolling-circle replication intermediates. Circularization of the same DNA before transfection led to a theta type of replication which generated supercoiled DNA molecules.

Cartilage surface charge. A possible determinant in aging and osteoarthritic processes.

Polycationic labels such as cationized ferritin and colloidal iron were used to evaluate the surface negative charges over the mandibular condyles of ICR mice. The effects of neuraminidase, hyaluronidase, pronase, and collagenase on the binding of cationized ferritin and colloidal iron particles to the condylar articular surface were also studied. The results of this study clearly indicate that the surface area of the cartilaginous condyle is negatively charged and that its composition consists mainly of a collagenous material embedded within a proteinaceous matrix.

Architecture and anatomy of the chromosomal locus in human chromosome 21 encoding the Cu/Zn superoxide dismutase.

The SOD-1 gene on chromosome 21 and approximately 100 kb of chromosomal DNA from the 21q22 region have been isolated and characterized. The gene which is present as a single copy per haploid genome spans 11 kb of chromosomal DNA. Heteroduplex analysis and DNA sequencing reveals five rather small exons and four introns that interrupt the coding region.

Evidence for a mechanical coupling of glycoprotein microfibrils with collagen fibrils in Wharton's jelly.

Wharton's jelly of human umbilical cord is known to contain hyaluronic acid and sulphated glycosaminoglycans (probably as proteoglycans) immobilized in an insoluble collagen fibril network. A secondary, independent, insoluble network based on glycoprotein microfibrils of 13 nm diameter and interpenetrated with the collagen network has now been found in amounts corresponding to 9% of the weight of collagen. Elastin, however, is absent.

Net albumin transport across the wall of the rabbit common carotid artery perfused in situ.

We have studied the transport of radioactively labelled albumin in the rabbit common carotid artery perfused in situ at 100 cm H2O luminal pressure in the anaesthetized living animal, assessing the distribution of concentration across the wall by means of sequential frozen sectioning. We have compared the findings with those of experiments in which we have attempted to saturate the wall with label. Our findings support the belief that there is a net transport of macromolecules across the arterial wall.

Surface charge and flow properties of endothelial membranes in aging rats.

The morphological features, surface charge and fluid properties of the membranes of aortic endothelial cells of young and old Wistar rats were studied by electron microscopy. Remarkable structural changes in the endothelial cells and subendothelial layer were observed in the aorta of old rats, due to accumulation of fibrillar and granular substances and cellular debris. Analysis of the possible age-related alterations in the permeability properties of the aortic endothelium indicated that positively charged macromolecules such as cationized ferritin are more rapidly transported through the endothelium of old rat aorta, as compared to young rats, thereby leading to their accumulation in the aortic intima of the old animal.

Age-related changes in aortic intima of rats.

The aortic intima of young and old Wistar rats was studied by light and electron microscopy. The endothelial cells of young rats are flat and regular and lie adjacent to the internal elastic lamina (IEL). Endothelial cells of old rats have irregular shapes and sizes and bulge into the lumen.