Unexpected reduction in reproduction of Collembola exposed to an arsenic-contaminated soil.

To assess the problems posed by ecological testing of the toxicity of polluted soils, we applied the Collembola reproduction test to the soil from a mining site polluted by metals. Our aim was to quantify the chronic toxicity of contaminated soil using the Folsomia candida reproduction test. Briefly, the polluted soil, which contains in particular large quantities of arsenic, is mixed in various proportions with a reference soil, and the number of juveniles is counted five weeks later.

Repression of transcription at the human T-cell receptor Vbeta2.2 segment is mediated by a MAX/MAD/mSin3 complex acting as a scaffold for HDAC activity.

The identification of protein components in complex networks of co-regulators responsible for the modulation of proliferation versus differentiation modes of cell growth is a major problem. We use a combination of surface enhanced laser desorption/ionization mass spectrometry, surface plasmon resonance coupled to electrospray mass spectrometry, and immunoelectromobility shift assays to identify members of the MAX/MAD family binding to a specific DNA silencer fragment involved in the regulation of transcription for the human T-cell receptor Vbeta2.2 segment.

Alternative lengthening of telomeres is characterized by high rates of telomeric exchange.

Telomere maintenance activity is a hallmark of cancer. In some telomerase-negative tumors, telomeres become lengthened by alternative lengthening of telomeres (ALT), a recombination-mediated DNA replication process in which telomeres use other telomeric DNA as a copy template. Using chromosome orientation fluorescence in situ hybridization, we found that postreplicative exchange events involving a telomere and another TTAGGG-repeat tract occur at remarkably high frequencies in ALT cells (range 28-280/100 metaphases) and rarely or never in non-ALT cells, including cell lines with very long telomeres.

The shortest telomeres drive karyotype evolution in transformed cells.

Maintenance of telomeres is essential for chromosome stability. In the absence of telomerase, telomeres shorten with cell division until they approach a stability threshold, at which point cells enter senescence. When senescence-signaling pathways are inactive, further telomere shortening leads to chromosome instability characterized by telomeric fusions and breakage-fusion-bridge (BFB) cycles.

Differences in telomere length between homologous chromosomes in humans.

Telomeres are important structures for DNA replication and chromosome stability during cell growth. Telomere length has been correlated with the division potential of human cells and has been found to decrease with age in healthy individuals. Nevertheless, telomere lengths within the same cell are heterogeneous and certain chromosome arms typically have either short or long telomeres.

Molecular characterization of germline NF2 gene rearrangements.

Neurofibromatosis type 2 (NF2) is an autosomal dominant disease that causes a predisposition to nervous system tumors. Deleterious point mutations have been found in about 55% of NF2 patients, and large genomic deletions account for approximately 33% of NF2 gene alterations. The majority of these deletions are larger than 50 kb, with a breakpoint usually lying outside the NF2 gene.

NF2 gene in neurofibromatosis type 2 patients.

Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder that predisposes to nervous system tumors. The schwannomin (also termed merlin) protein encoded by the NF2 gene shows a close relationship to the family of cytoskeleton-to-membrane proteins linkers ERM (ezrin-radixin-moesin proteins). Even though penetrance of the disease is >95% and no genetic heterogeneity has been described, point mutations in the NF2 gene have been observed in only 34-66% of the screened NF2 patients, depending on the series.

Comparison of the enzyme activities between the thickest and the thinnest parts of the abdominal pannus.

Objective: According to some reports, there are variations in metabolism in adipocytes from different areas of the body. The purpose of this study was to determine if there are differences in some of the lipid assimilating enzyme activities between the thickest (overhang) and the thinnest (upper margin) parts of the abdominal pannus.

Methods: The abdominal panniculectomy activities of sn-glycerol-3-phosphate dehydrogenase (31 subjects, spectrophotometric method), fatty acid synthetase (14 subjects, spectrophotometric method) and lipoprotein lipase (18 subjects, radioactive method) were determined in the thickest and the thinnest parts of the pannus of lipectomy patients.

Activation of the human homologue of the Drosophila sina gene in apoptosis and tumor suppression.

Developmentally regulated genes in Drosophila, which are conserved through evolution, are potential candidates for key functions in biological processes such as cell cycle, programmed cell death, and cancer. We report cloning and characterization of the human homologue of the Drosophila seven in absentia gene (HUMSIAH), which codes for a 282 amino acids putative zinc finger protein. HUMSIAH is localized on human chromosome 16q12-q13.

Isolation of 10 differentially expressed cDNAs in p53-induced apoptosis: activation of the vertebrate homologue of the drosophila seven in absentia gene.

We report the isolation of 10 differentially expressed cDNAs in the process of apoptosis induced by the p53 tamor suppressor. As a global analytical method, we performed a differential display of mRNA between mouse M1 myeloid leukemia cells and derived clone LTR6 cells, which contain a stably transfected temperature-sensitive mutant of p53. At 32 degrees C wild-type p53 function is activated in LTR6 cells, resulting in programmed cell death.

Effect of Abdominal Lipectomy on Lipid Profile, Glucose Handling and Blood Pressure in Patients with Truncal Obesity.

BACKGROUND: Previous studies have found that people with apple (android)-shaped body fat distribution are at risk of developing cardiovascular disease, impaired glucose tolerance and hypertension. METHODS: To investigate the effects of lipectomy, we measured lipid and lipoprotein levels, indices associated with glucose tolerance and blood-pressure. The tests were performed pre-operatively and 3 and 12 months post-operatively in 34 subjects (obese lipectomy patients with android-shaped body fat distribution) and 23 controls (obese breast reduction patients).