Sister DNA Entrapment between Juxtaposed Smc Heads and Kleisin of the Cohesin Complex.

Cohesin entraps sister DNAs within tripartite rings created by pairwise interactions between Smc1, Smc3, and Scc1. Because Smc1/3 ATPase heads can also interact with each other, cohesin rings have the potential to form a variety of sub-compartments. Using in vivo cysteine cross-linking, we show that when Smc1 and Smc3 ATPases are engaged in the presence of ATP (E heads), cohesin rings generate a "SMC (S) compartment" between hinge and E heads and a "kleisin (K) compartment" between E heads and their associated kleisin subunit.

Xenobiotics in vitro: the influence of L-cystine, pantothenat, and miliacin on metabolic and proliferative capacity of keratinocytes.

To investigate the effect of cell growth-stimulating agents on human epidermal keratinocytes, we exposed monolayers of normal human keratinocytes derived from foreskin to different concentrations of the amino acid L-cystine, the member of the vitamin B family D-pantothenat, the phytosterol miliacin, and a combination thereof in keratinocyte growth medium. As a test system for the metabolic capacity, we used the activity of mitochondrial deyhdrogenases as measured by XTT, and for the cell proliferation, we determined the BrdU-uptake. The additives, active ingredients of the hair growth drug PRIORIN, were added in the presence of fully supplemented keratinocyte growth medium or a deficient medium without L-cystine, L-methionine, L-histidin, D-pantothenat, epidermal growth factor, and bovine pituary gland extract.

Folic acid treatment in males and females with fragile-(X)-syndrome.

Ten males with the fragile X (fra(X] syndrome were treated with folic acid (10 mg/day) for 4 months in a double-blind design study. To eight heterozygotes with mental impairment and fra(X), folic acid was given for 4 months (10 mg/day) in an effort to study possible beneficial effects of folic acid. Psychological and cytogenetic testing were carried out during the trial.