Bloom syndrome is an autosomal recessive genetic disease. Cells from patients with this disease are characterized by high levels of chromosome aberrations and sister chromatid exchanges. We show here that the frequency of these chromosomal changes is markedly reduced when the cells are grown in the presence of certain protease inhibitors. In relation to other published data, our results suggest...

Although Blm and Top3α are known to form a minimal dissolvasome that can uniquely undo a double Holliday junction structure, the details of the mechanism remain unknown. It was originally suggested that Blm acts first to create a hemicatenane structure from branch migration of the junctions, followed by Top3α performing strand passage to decatenate the interlocking single strands. Recent eviden...

Cell lines derived from seven patients with Bloom syndrome all contain a DNA ligase I with unusual properties. Six lines were shown to have a reduced level of this enzyme activity and the residual enzyme was anomalously heat-labile. The seventh line contained a dimeric rather than monomeric form of ligase I. Several cell lines representative of other inherited human syndromes have apparently no...

Werner syndrome and Bloom syndrome result from defects in the RecQ helicases Werner (WRN) and Bloom (BLM), respectively, and display premature aging phenotypes. Similarly, XFE progeroid syndrome results from defects in the ERCC1-XPF DNA repair endonuclease. To gain insight into the origin of cellular senescence and human aging, we analyzed the dependence of sister chromatid exchange (SCE) frequ...

Loss of Werner syndrome helicase-exonuclease (WRN) or of its homolog Bloom syndrome helicase (BLM) results in different inherited disorders. Whereas Werner syndrome is characterized by premature onset of aging and age-associated diseases, Bloom syndrome involves developmental abnormalities and increased predisposition to diverse malignancies. To identify biochemical differences between WRN and ...

Bloom syndrome and Werner syndrome are genome instability disorders, which result from mutations in two different genes encoding helicases. Both enzymes are members of the RecQ family of helicases, have a 3' --> 5' polarity, and require a 3' single strand tail. In addition to their activity in unwinding duplex substrates, recent studies show that the two enzymes are able to unwind G2 and G4 tet...

OBJECTIVE To determine whether general cognitive ability, basic mathematic processing, and mathematic attainment are universally affected by gestation at birth, as well as whether mathematic attainment is more strongly associated with cohort-specific factors such as schooling than basic cognitive and mathematical abilities. STUDY DESIGN The Bavarian Longitudinal Study (BLS, 1289 children, 27-...

In 1981, employees in medium and large size establishments received, on average, about 10 paid holidays each year and nearly 16 days of paid vacation annually after 10 years of service. For 3 of 5 participants in a life insurance plan, coverage was based on earnings, with the prevalence of earnings-related plans much higher among white-collar employees. Seventy-one percent of the workers covere...