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41.
Erwin Märtlbauer Ewald Usleber Richard Dietrich Elisabeth Schneider 《Mycotoxin Research》2009,25(4):175-186
In a long-term study (1990–1997) on ochratoxin A (OTA) in human blood serum, 102 serum samples from 36 persons of the Munich
Institute for Hygiene and Technology of Food of Animal Origin were analysed by enzyme immunoassay (EIA), and by high performance
liquid chromatography (HPLC) for control. Detection limits were at 50 pg/ml (EIA) and 50–70 pg/ml (HPLC), recoveries were
80–120% (EIA) and 30–60% (LC). OTA was detected in 98% (EIA, 368 ± 217 pg/ml) and 93% (HPLC, 271 ± 170 pg/ml) of samples (maximum
1,290 pg/ml). Using published conversion factors for serum/intake estimates (1.34 or 1.97), the mean daily OTA intake of these
36 persons was 493–725 pg/kg bw. Long-term individual mean OTA levels of nine persons ranged from 162 ± 80 pg/ml to 549 ± 172 pg/ml.
Our data were compared with published OTA serum levels (1985–2008) for apparently healthy persons from a total of 30 countries.
On a worldwide basis, the mean of means for OTA in human serum was estimated to be 700 pg/ml, corresponding to a mean daily
OTA intake of 940–1380 pg/kg bw. This level, which was relatively stable over the last decades, is well below published tolerable
daily intake values (14,000–18,000 pg/kg bw). 相似文献
42.
Antonio Cabrera Umesh R. Rosyara Paolo De Franceschi Audrey Sebolt Suneth S. Sooriyapathirana Elisabeth Dirlewanger Jose Quero-Garcia Mirko Schuster Amy F. Iezzoni Esther van der Knaap 《Tree Genetics & Genomes》2012,8(2):237-247
The Rosaceae Conserved Orthologous Set (RosCOS) provides a gene-based genome-wide set of markers that have been used in comparative
analyses of peach (Prunus persica), apple (Malus × domestica), and strawberry (Fragaria spp.). In order to extend the use of these RosCOS to sweet cherry (Prunus avium L.), we identified markers that are polymorphic in breeding germplasm. Ninety-five percent (595/627) of previously designed
RosCOS primer pairs amplified a product in six sweet cherry cultivars predicted to represent the range of genetic diversity
in breeding germplasm. A total of 45% (282/627) RosCOS were polymorphic among the six cultivars, and allele number ranged
from 2 to 6, with a genome-wide mean of 2.35. A subset of 92 genome-wide single nucleotide polymorphisms (SNPs) corresponding
to 76 RosCOS was analyzed in 36 founder accessions and progeny. The expected and observed heterozygosity suggested that 83%
of the RosCOS were in Hardy–Weinberg equilibrium, implying that most RosCOS behave as neutral markers. Principal coordinate
analysis (PCO) identified one wild accession and two Spanish landraces that clustered differently from the other accessions.
The relatively high number of unique alleles found in the three differentially clustered selections suggested that their use
as parents has potential to increase the genetic diversity in future US-bred cultivars. Of the 92 RosCOS SNPs, 81 SNPs that
represented 68 genome-wide RosCOS segregated in four mapping populations. These RosCOS were mapped in four F1 populations, thereby greatly improving the genetic linkage map of sweet cherry. 相似文献
43.
Multimeric BLM is dissociated upon ATP hydrolysis and functions as monomers in resolving DNA structures 总被引:1,自引:0,他引:1
Ya-Nan Xu Nicolas Bazeille Xiu-Yan Ding Xi-Ming Lu Peng-Ye Wang Elisabeth Bugnard Virginie Grondin Shuo-Xing Dou Xu Guang Xi 《Nucleic acids research》2012,40(19):9802-9814
Bloom (BLM) syndrome is an autosomal recessive disorder characterized by an increased risk for many types of cancers. Previous studies have shown that BLM protein forms a hexameric ring structure, but its oligomeric form in DNA unwinding is still not well clarified. In this work, we have used dynamic light scattering and various stopped-flow assays to study the active form and kinetic mechanism of BLM in DNA unwinding. It was found that BLM multimers were dissociated upon ATP hydrolysis. Steady-state and single-turnover kinetic studies revealed that BLM helicase always unwound duplex DNA in the monomeric form under conditions of varying enzyme and ATP concentrations as well as 3′-ssDNA tail lengths, with no sign of oligomerization being discerned. Measurements of ATPase activity further indicated that BLM helicase might still function as monomers in resolving highly structured DNAs such as Holliday junctions and D-loops. These results shed new light on the underlying mechanism of BLM-mediated DNA unwinding and on the molecular and functional basis for the phenotype of heterozygous carriers of BLM syndrome. 相似文献
44.
Cryopreserved human haematopoietic stem cells retain engraftment potential after extended (5-14 years) cryostorage 总被引:3,自引:0,他引:3
Harvesting of stem cells during the early phases of treatment with no immediate intention to perform a stem cell transplant is becoming an increasingly common practice. Such "insurance" harvests are often stored for many years before being needed for transplant in a subsequent relapse. The effect of long-term cryostorage (5-14 years) on the viability and functional capacity of haematopoietic stem cells (HSCs) was investigated in 40 bone marrow and peripheral blood harvests using standard in vitro methods, the colony forming unit-granulocyte/macrophage (CFU-GM) assay and a single platform viable CD34(+) cell absolute count by flow cytometry. Forty percent of harvests had CD34(+) HSC counts of at least 0.7 x 10(6)/kg bodyweight and 85% had CFU-GM counts of at least 1.0 x 10(5)/kg bodyweight, these values representing our institutional minimum requirements for safe transplantation. Based on these results, it appears that HSC collections can remain adequate for safe transplantation after up to 14 years of cryostorage. However, as deterioration of HSC quality and viability may occur, some precautions may be warranted, namely harvesting higher than normal numbers of HSCs in collections intended for long-term storage and repeating in vitro assays on harvests after long-term storage prior to transplantation. 相似文献
45.
Elisabeth Ekener-Petersen Göran Finnveden 《The International Journal of Life Cycle Assessment》2013,18(1):127-143
Purpose
A generic hotspot assessment of social impacts from a product was conducted, using a laptop computer as a case. The aims of the case study were to identify social hotspots of the laptop and to test and evaluate the methodology.Methods
The case study was based on the social LCA methodology described in the Guidelines for social LCA and included the product system from ‘cradle to grave’ as well as the impacts on all relevant stakeholders. We focused on a simplified list of materials and used mainly country-specific data.Results and discussion
A new method for impact assessment of hotspots was developed. The total activity in each phase was distributed among countries. The countries were divided into groups related to the extent of activity in the product system, as well as to their performance on a subcategory. High values in both groups were highlighted and hotspots were identified. The results revealed some hotspots, some hot countries and some hot issues, all indicating a risk of negative social impacts in the product system of a laptop. It also identified workers and the local community as the stakeholders most at risk of negative social impacts. Among the hotspots identified, the following subcategories were of importance: safe and healthy living conditions, social benefit/social security, access to material resources, involvement in areas with armed conflicts, community engagement (lack of), corruption, and access to immaterial resources.Conclusions
The study showed it is possible to conduct a social LCA on a generic complex product using the Guidelines, even though data collection was impaired by lack of data and low data quality. It identified methodological issues that need further attention, for example the indicator impact pathways. Still, it is clear that new insights can be gained by social LCA, where the life cycle perspective and the systematic approach help users identify potentially important aspects that could otherwise have been neglected. 相似文献46.
Christiane Elisabeth S?rensen Katerina Tritsaris Jesper Reibel Martin Lauritzen Erik Lykke Mortensen Merete Osler Anne Marie Lynge Pedersen 《PloS one》2016,11(3)
Background
The cell-cycle inhibitor and tumor suppressor cyclin dependent kinase inhibitor, p16ink4a, is one of the two gene products of the ink4a/ARF (cdkn2a) locus on chromosome 9q21. Up-regulation of p16ink4a has been linked to cellular senescence, and findings from studies on different mammalian tissues suggest that p16ink4a may be a biomarker of organismal versus chronological age.Objective
The aim of this study was to examine the immunolocalization pattern of p16ink4a in human labial salivary gland (LSG) tissue, and to analyze whether its expression level in LSGs is a peripheral correlate of cognitive decline in late midlife.Methods
The present study was a part of a study of causes and predictors of cognitive decline in middle-aged men in a Danish birth cohort. It is based on data from 181 male participants from the Danish Metropolit birth cohort, born in 1953, who were examined for age-associated alterations in cognition, dental health, and morphological and autonomic innervation characteristics of the LSGs. The participants were allocated to two groups based on the relative change in cognitive performance from young adulthood to late midlife. LSG biopsies were analyzed by qRT-PCR for the expression level of p16ink4a. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded sections of LSGs.Results
p16ink4a immunoreactivity was observed in LSG ductal, myoepithelial, and stromal cells, but not in acinar cells. The mean relative expression of p16ink4a in LSGs was higher in the group of participants with decline in cognitive performance. A logistic regression analysis revealed that the relative p16 expression was predictive of the participant’s group assignment. A negative correlation was found between relative p16ink4a expression and the participant’s standardized regression residuals from early adulthood to late midlife cognitive performance scores.Conclusions
p16ink4a expression in human LSGs may constitute a potential peripheral correlate of cognitive decline. Human labial salivary glands seem suitable for studies on organismal as opposed to chronological age. 相似文献47.
48.
Roger Miras Isabelle Morin Florent Guillain Elisabeth Mintz 《Journal of biological inorganic chemistry》2008,13(2):195-205
Copper is both an essential element as a catalytic cofactor and a toxic element because of its redox properties. Once in the
cell, Cu(I) binds to glutathione (GSH) and various thiol-rich proteins that sequester and/or exchange copper with other intracellular
components. Among them, the Cu(I) chaperone Atx1 is known to deliver Cu(I) to Ccc2, the Golgi Cu–ATPase, in yeast. However,
the mechanism for Cu(I) incorporation into Atx1 has not yet been unraveled. We investigated here a possible role of GSH in
Cu(I) binding to Atx1. Yeast Atx1 was expressed in Escherichia coli and purified to study its ability to bind Cu(I). We found that with an excess of GSH [at least two GSH/Cu(I)], Atx1 formed
a Cu(I)-bridged dimer of high affinity for Cu(I), containing two Cu(I) and two GSH, whereas no dimer was observed in the absence
of GSH. The stability constants (log β) of the Cu(I) complexes measured at pH 6 were 15–16 and 49–50 for CuAtx1 and Cu2I(GS−)2(Atx1)2, respectively. Hence, these results suggest that in vivo the high GSH concentration favors Atx1 dimerization and that Cu2I(GS−)2(Atx1)2 is the major conformation of Atx1 in the cytosol. 相似文献
49.
Larval gonads of Drosophila hydei, homozygous for the lethal gene l(3)pl (lethal-polyploid), were cultured in normal hosts. Ovaries of the late third larval instar were implanted into metamorphosing larvae. These can attach to the gonoduct system of the host and transform into adult ovarian structures but the spectrum of their capacity to differentiate varies largely. In favourable cases mature oocytes can be formed which are fertile. More frequently mitotic disturbances in the follicle cells and cystocytes lead to the formation of abortive egg chambers and abnormally shaped oocytes. Testes of the middle third larval instar were cultured for 2 weeks in adult females. Primary spermatocytes are able to sustain meiotic divisions and form early spermatids, even though the occurrence of fractionated nuclei in post-meiotic germ cells indicates defective meiotic divisions. Post-meiotic differentiation is blocked in mutant spermatids which fail to elongate. The mutant gene l(3)pl thus, not only affects cell divisions, but also interacts in certain cytodifferentiation processes such as spermatid elongation and egg shaping. All cellular processes found so far to be abnormal in mutant tissues involve microtubular function. This suggests that the gene l(3)pl interacts with the microtubular system and several aspects of this interpretation are discussed. 相似文献
50.
Lundin KE Ge R Svahn MG Törnquist E Leijon M Brandén LJ Smith CI 《Biomolecular engineering》2004,21(2):51-59
Peptide nucleic acid (PNA) is a DNA analog with broad biotechnical applications, and possibly also treatment applications. Its suggested uses include that of a specific anchor sequence for biologically active peptides to plasmids in a sequence-specific manner. Such complexes, referred to as Bioplex, have already been used to enhance non-viral gene transfer in vitro. To investigate how hybridization of PNAs to supercoiled plasmids would be affected by the binding of multiple PNA-peptides to the same strand of DNA, we have developed a method of quantifying the specific binding of PNA using a PNA labeled with a derivative of the fluorophore thiazole orange (TO). Cooperative effects were found at a distance of up to three bases. With a peptide present at the end of one of the PNAs, steric hindrance occurred, reducing the increase in binding rate when the distance between the two sites was less than two bases. In addition, we found increased binding kinetics when two PNAs binding to overlapping sites on opposite DNA strands were used, without the use of chemically modified bases in the PNAs. 相似文献