Positive tetracycline control of expression of p15INK4B from an Epstein-Barr autonomous plasmid in a human melanoma cell line.

Homozygous deletions in the region of chromosome 9p21 are frequent in human melanoma. Mutations in the p16INK4A cyclin-dependent kinase inhibitor (CDI) gene at this locus have implicated the product of this gene as a tumor suppressor. Less attention has been focused on the homologous, closely linked p15INK4B gene.

Inflammatory nevus comedonicus in children.

More than 100 years has passed since the first report of a nevus comedonicus. The earliest reports emphasized the inflammatory aspect of the nevus comedonicus as being the most significant problem. In the past 30 years, publications have ignored the inflammatory aspect of nevus comedonicus while emphasizing a variety of associated malformations.

Uncoordinate regulation of collagenase, stromelysin, and tissue inhibitor of metalloproteinases genes by prostaglandin E2: selective enhancement of collagenase gene expression in human dermal fibroblasts in culture.

The degradative effects of interleukin-1 (IL-1) on the extracellular matrix of connective tissue are mediated primarily by metalloproteinases and prostaglandins. Clinical observations suggest that these effects can be prevented, to some extent, by the use of non-steroidal anti-inflammatory drugs. We have examined the role of prostaglandin E2 (PGE2) in IL-1-induced gene expression by human skin fibroblasts in culture.

Effects of secretin and caerulein on pancreatic digestive enzymes in cultured rat acinar cells.

Caerulein is proposed to regulate the synthesis of pancreatic proteases and amylase. Similarly, secretin is implicated in the regulation of pancreatic lipase synthesis. Evidence of these regulations is predominantly from in vivo studies.

Acceleration of asynchronous enzyme transport in the rat exocrine pancreas following hormonal stimulation in vivo.

We have measured the rate of secretion in vitro of individual rat exocrine pancreatic enzymes and proenzymes from cells in pancreatic lobules of control animals and animals subjected to 24 h optimal hormonal prestimulation with cerulein, in vivo. With the controls secreted proteins were first detectable at 20 to 25 min of chase after a 5-min pulse label, and the amount of total secretion increased slowly thereafter. With stimulated lobules secretion was first detectable at 10 to 15 min postpulse.

Isolation and sequence of the canine pancreatic phospholipase A2 gene.

A genomic library has been constructed in EMBL3 lambda phage using high molecular mass DNA isolated from canine spleen. A cDNA clone, shown to code for preprophospholipase A2 which is processed to the prosecretory form prior to release from secretory cells, was used to identify a lambda clone which contains the complete phospholipase A2 gene. Restriction enzyme and DNA sequence analysis indicate that the primary transcriptional unit for the phospholipase gene, approximately 9.

Lipase synthesis in the rat pancreas is regulated by secretin.

Conscious rats were infused with optimal doses of secretin (16 clinical units [CU]/kg/h), cerulein (0.25 microgram/kg/h), and both for varying periods of time over 24 h. The presence of zymogen granules in acinar cells and the tissue content of enzymes showed progressive decreases over 3 and 12 h for cerulein and secretin stimulation, respectively.

In-vivo stimulation of rat pancreatic acinar cells by infusion of secretin. II. Changes in individual rates of enzyme and isoenzyme biosynthesis.

Intravenous infusion of synthetic secretin for periods up to 24 h in conscious rats was combined with in-vitro amino acid incorporation in isolated pancreatic lobules and high-resolution separation of individual enzyme proteins by two-dimensional isoelectric focusing and SDS gel electrophoresis. With this method persistent changes in the biosynthesis of ten enzyme and isoenzyme proteins can be studied as a result of prolonged secretin stimulation. Three major patterns of response were observed: progressive increases in the synthetic rates were found in six out of ten enzyme proteins with most pronounced changes in the synthetic rates of lipase (4.

In-vivo stimulation of rat pancreatic acinar cells by infusion of secretin. I. Changes in enzyme content, pancreatic fine structure and total rate of protein synthesis.

Infusion of synthetic secretin in conscious unrestricted rats for periods up to 24 h was used to study the structural and functional adaptation of pancreatic acinar cells to this secretagogue. Initial dose-response studies established 16 clinical units (CU) per kg and h (corresponding to 4.64 micrograms X kg-1 X h-1) as optimal dose for persistent stimulation of enzyme discharge.