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1.
Sergio Cardoso Laura Valverde Miguel A. Alfonso-Sánchez Leire Palencia-Madrid Xabier Elcoroaristizabal Jaime Algorta Susana Catarino David Arteta Rene J. Herrera María Teresa Zarrabeitia José A. Pe?a Marian M. de Pancorbo 《PloS one》2013,8(7)
The European genetic landscape has been shaped by several human migrations occurred since Paleolithic times. The accumulation of archaeological records and the concordance of different lines of genetic evidence during the last two decades have triggered an interesting debate concerning the role of ancient settlers from the Franco-Cantabrian region in the postglacial resettlement of Europe. Among the Franco-Cantabrian populations, Basques are regarded as one of the oldest and more intriguing human groups of Europe. Recent data on complete mitochondrial DNA genomes focused on macrohaplogroup R0 revealed that Basques harbor some autochthonous lineages, suggesting a genetic continuity since pre-Neolithic times. However, excluding haplogroup H, the most representative lineage of macrohaplogroup R0, the majority of maternal lineages of this area remains virtually unexplored, so that further refinement of the mtDNA phylogeny based on analyses at the highest level of resolution is crucial for a better understanding of the European prehistory. We thus explored the maternal ancestry of 548 autochthonous individuals from various Franco-Cantabrian populations and sequenced 76 mitogenomes of the most representative lineages. Interestingly, we identified three mtDNA haplogroups, U5b1f, J1c5c1 and V22, that proved to be representative of Franco-Cantabria, notably of the Basque population. The seclusion and diversity of these female genetic lineages support a local origin in the Franco-Cantabrian area during the Mesolithic of southwestern Europe, ∼10,000 years before present (YBP), with signals of expansions at ∼3,500 YBP. These findings provide robust evidence of a partial genetic continuity between contemporary autochthonous populations from the Franco-Cantabrian region, specifically the Basques, and Paleolithic/Mesolithic hunter-gatherer groups. Furthermore, our results raise the current proportion (≈15%) of the Franco-Cantabrian maternal gene pool with a putative pre-Neolithic origin to ≈35%, further supporting the notion of a predominant Paleolithic genetic substrate in extant European populations. 相似文献
2.
Background
Radial chromosome positioning in interphase nuclei is nonrandom and can alter according to developmental, differentiation, proliferation, or disease status. However, it is not yet clear when and how chromosome repositioning is elicited. 相似文献3.
4.
Joanna Nakonieczna Ewelina Michta Magda Rybicka Mariusz Grinholc Anna Gwizdek-Wiśniewska Krzysztof P Bielawski 《BMC microbiology》2010,10(1):323
Background
Staphylococcus aureus, a major human pathogen causes a wide range of disease syndromes. The most dangerous are methicillin-resistant S. aureus (MRSA) strains, resistant not only to all β-lactam antibiotics but also to other antimicrobials. An alarming increase in antibiotic resistance spreading among pathogenic bacteria inclines to search for alternative therapeutic options, for which resistance can not be developed easily. Among others, photodynamic inactivation (PDI) of S. aureus is a promising option. Photodynamic inactivation is based on a concept that a non toxic chemical, called a photosensitizer upon excitation with light of an appropriate wavelength is activated. As a consequence singlet oxygen and other reactive oxygen species (e.g. superoxide anion) are produced, which are responsible for the cytotoxic effect towards bacterial cells. As strain-dependence in photodynamic inactivation of S. aureus was observed, determination of the molecular marker(s) underlying the mechanism of the bacterial response to PDI treatment would be of great clinical importance. We examined the role of superoxide dismutases (Sod) in photodynamic inactivation of S. aureus as enzymes responsible for oxidative stress resistance. 相似文献5.
Nathan Downs Alfio Parisi Joanna Turner David Turnbull 《Photochemical & photobiological sciences》2008,7(6):700-710
A technique has been developed to represent erythemally effective ultraviolet radiation exposure within a school environment. The technique models the erythemally effective exposure onto a horizontal plane representation of a mapped school environment located in Hervey Bay (25 degrees S, 153 degrees E), Australia. The input parameters used to model the ultraviolet exposures received within the school playground included the measured sky view, ground albedo and standing surface albedo. Estimates of the erythemally effective ultraviolet exposure received within the school playground during morning tea and lunch time meal breaks during a winter and summer school day are presented. The influence of tree shade and building structure was found to vary significantly with solar zenith angle modelled over the winter and summer school meal break times with horizontal plane exposures predicted to vary from between 0 and 7 SED at different locations within the playground. The technique presented provides a method that can be followed to examine the effect of surrounding buildings and surface structures of real environments on the predicted horizontal plane ultraviolet exposure. 相似文献
6.
Carroll D. Arnett Joanna S. Fowler Robert R. MacGregor David J. Schlyer Alfred P. Wolf Bengt Långström Christer Halldin 《Journal of neurochemistry》1987,49(2):522-527
The distribution of carbon-11-labeled L-deprenyl, an irreversible inhibitor of monoamine oxidase type B (MAO-B), was determined in the baboon brain by positron emission tomography. The irreversible blood-to-brain transfer constant (influx constant, Ki) was measured using a complete metabolite-corrected arterial plasma concentration curve. This influx constant was used as a measure of functional enzyme activity for sequential determinations of MAO-B recovery following a single high dose of unlabeled l -deprenyl. The half-life for turnover of MAO-B was thus determined to be 30 days. Using appropriate irreversible inhibitors, this procedure should be generally useful for determining enzyme turnover rates in any organ in vivo and can be applied to some human studies as well. 相似文献
7.
M L Pita M D Girón M Pérez-Ayala C DeLucchi A Martínez Valverde A Gil 《Clinical physiology and biochemistry》1989,7(5):238-248
Diet and postnatal age effect the fatty acid composition of plasma and tissue lipids. This work was designed as a transversal study to evaluate the changes in the fatty acid composition of plasma phospholipids, cholesteryl esters, triglycerides and free fatty acids in preterm infants (28-35 weeks gestational age), fed human milk (HM) and milk formula (MF) from birth to 1 month of life. Sixteen blood samples were obtained from cord, and 19 at 6-8 h after birth, 14 at 1 week and 9 at 4 weeks from HM-fed infants and 18 at 1 week and 14 at 4 weeks from MF-fed ones. Groups had similar mean birth weight, gestational age and sex ratio. The MF provided 69 kcal/dl and contained 16% of linoleic acid and 1.3% of alpha-linolenic acid on the total fat. Plasma lipid fractions were extracted and separated by thin-layer chromatography and fatty acid methyl esters were quantitated by gas liquid chromatography. In plasma phospholipids, linoleic acid (18:2 omega 6) continuously increased from birth to 1 month of age, but no changes were seen as related to type of diet; polyunsaturated fatty acids greater than 18 carbon atoms of both the omega 6 and omega 3 series (PUFA omega 6 greater than 18 C and omega 3 greater than 18 C) dropped from birth to 1 week and continued to decrease in MF-fed infants until 1 month; eicosatrienoic (20:3 omega 6), arachidonic (20:4 omega 6) and docosahexaenoic (22:6 omega 3) were the fatty acids implicated. In cholesteryl esters palmitoleic (16:1 omega 7) and oleic (18:1 omega 9) acids decreased from birth to 1 month and linoleic acid increased and arachidonic acid dropped, especially in MF fed infants. In triglycerides, palmitic, palmitoleic and stearic acid (18:0) decreased during the first month of life; oleic acid remained constant and linoleic acid increased in all infants, but arachidonic acid decreased only in those fed formula. Free fatty acids showed a similar behavior in fatty acids and in plasma triglycerides. Preterm neonates seem to have special requirements of long-chain PUFA and adapted MF should contain these fatty acids in similar amounts to those of HM to allow the maintenance of an adequate tissue structure and physiology. 相似文献
8.
Insulin signal transmission through the plasma membrane was studied in terms of relationship between basal autophosphorylation of the β-subunit and the ability by bind insulin by the -subunit of the insulin receptor. In a cell free system, receptors phosphorylated on tyrosine residues in the absence of insulin were separated from non-phosphorylated receptors using antiphosphotyrosine antibodies. Insulin binding assays were then performed on basally autophosphorylated and on non-phosphorylated receptors. We found that the tyrosine phosphorylated receptors, which corresponded to 25% of the total number of receptors, were accountable for 60–80% of insulin binding. Scatchard representation of binding data has shown that the plot corresponding to tyrosine phosphorylated receptors was localized above, and was steeper than the plot corresponding to non-phosphorylated receptors. These data make it likely that the conformation of -subunit which favours ligand binding is connected to the conformation of β-subunit which favours phosphate reception on tyrosine residues. Reciprocally, the high-affinity conformation of insulin receptor seems to become stabilized by basal autophosphorylation. 相似文献
9.
A rapid method for measuring the in vitro attachment of Candida albicans to the surface of transparent acrylic is described. The method involves use of the 'Magiscan' automated image analysis system which measures attachment in terms of percentage area coverage. These measurements correlate highly significantly ( P < 0·001) with the number of adherent yeast cells. 相似文献
10.
Prevalence of the 281 (Gly→Glu) mutation in hepatoerythropoietic porphyria and porphyria cutanea tarda 总被引:4,自引:0,他引:4
Hubert de Verneuil Joanna Hansen Christiane Picat Bernard Grandchamp James Kushner Andrew Roberts George Elder Yves Nordmann 《Human genetics》1988,78(1):101-102
Summary The prevalence of the 281 (GlyGlu) mutation in hepatoerythropoietic porphyria (HEP) was investigated by the use of hybridization with a synthetic oligonucleotide probe. The mutation was found in HEP-affected members of two unrelated families from Spain, but was absent in two other patients from Italy and Portugal who also had HEP. Moreover, this mutation was not detected in 13 unrelated cases of familial (type II) porphyria cutanea tarda. 相似文献