The increased susceptibility of mouse cells to fluorescent light-induced chromatid damage following their spontaneous malignant transformation in culture could result from loss or inactivation of catalase that decomposes the photoproduct H2O2 or from impaired capacities to repair DNA damage. No consistent change in catalase activity with respect to neoplastic state could be established. To inte...

In This Issue In This Issue Saying NO to muscular dystrophy ccording to the prevailing model for Duchenne muscular dystrophy (DMD) pathogenesis, a lack of dystrophin protein makes muscle cells susceptible to mechanical damage, leading to muscle breakdown. On page 123, Wehling et al. suggest that the major damage in DMD may actually be caused by a secondary consequence of dystrophin loss: destru...

The cohesin complex topologically encircles chromosomes and mediates sister chromatid cohesion to ensure accurate chromosome segregation upon cell division. Cohesin also participates in DNA repair and gene transcription. The Nipped-B-Mau2 protein complex loads cohesin onto chromosomes and the Pds5-Wapl complex removes cohesin. Pds5 is also essential for sister chromatid cohesion, indicating tha...

An automatic system for detecting and counting sister chromatid exchanges in human chromosomes has been developed. Metaphase chromosomes from lymphocytes which had incorporated 5-bromodeoxyuridine for two replication cycles were treated with the dye 33258 Hoechst and photodegraded so that the sister chromatids exhibited differential Giemsa staining. A computer-controlled television-microscope s...

Abnormally high levels of spontaneous and mitomycin C or diepoxybutane induced chromosome breakage were observed in lymphocytes from eight out of nine previously undescribed patients clinically diagnosed as having Fanconi's anaemia. The results suggest that the combination of spontaneous and induced chromosome breakage is a good aid in the differential diagnosis and we suggest that increased ch...

Literature dealing with the mechanisms of hair breakage in combing and brushing published so far has been reviewed as a background for the critical evaluation of the method and data analysis of the paper “Statistical Analysis of Hair Breakage. II” by Evans and Park (1). Accumulated knowledge about hair breakage in these grooming processes indicates that hair breakage in combing and brushing res...

Rationale: Cardiac progenitor cells (CPCs) in the adult heart are used for cell-based treatment of myocardial damage, but factors determining stemness, self-renewal, and lineage commitment are poorly understood. Immortal DNA strands inherited through asymmetric chromatid segregation correlate with self-renewal of adult stem cells, but the capacity of CPCs for asymmetric segregation to retain im...

Sister-chromatid cohesion, the process of pairing replicated chromosomes during mitosis and meiosis, is mediated through the essential cohesin complex and a number of nonessential cohesion genes, but the specific roles of these nonessential genes in sister-chromatid cohesion remain to be clarified. We analyzed sister-chromatid cohesion in double mutants of mrc1Delta, tof1Delta, and csm3Delta an...

PURPOSE To determine the number of initial chromatid breaks induced by low- or high-LET irradiations, and to compare the kinetics of chromatid break rejoining for radiations of different quality. MATERIAL AND METHODS Exponentially growing human fibroblast cells AG1522 were irradiated with gamma-rays, energetic carbon (290MeV/u), silicon (490MeV/u) and iron (200 and 600 MeV/u). Chromosomes wer...

the effective factors of forward speed, cylinder rotation, and clearance between a combine’s cylinder and concave on wheat kernel breakage and seed germination were studied in karaj area using a 955 model john dear combine. this study was conducted on three levels of adjustment for each of the variables, 1.2, 1.8 and 2.5 km/hr for forward speed, 800, 900, 1000 rpm for cylinder rotation as well ...