987 resultados para gE deletion


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L-alpha-glycerophosphate oxidase (GlpO) plays a central role in virulence of Mycoplasma mycoides subsp. mycoides SC, a severe bacterial pathogen causing contagious bovine pleuropneumonia (CBPP). It is involved in production and translocation of toxic H(2)O(2) into the host cell, causing inflammation and cell death. The binding site on GlpO for the cofactor flavin adenine dinucleotide (FAD) has been identified as Gly(12)-Gly(13)-Gly(14)-Ile(15)-Ile(16)-Gly(17). Recombinant GlpO lacking these six amino acids (GlpODeltaFAD) was unable to bind FAD and was also devoid of glycerophosphate oxidase activity, in contrast to non-modified recombinant GlpO that binds FAD and is enzymatically active. Polyclonal monospecific antibodies directed against GlpODeltaFAD, similarly to anti-GlpO antibodies, neutralised H(2)O(2) production of M. mycoides subsp. mycoides SC grown in the presence of glycerol, as well as cytotoxicity towards embryonic calf nasal epithelial (ECaNEp) cells. The FAD-binding site of GlpO is therefore suggested as a valuable target site for the future construction of deletion mutants to yield attenuated live vaccines of M. mycoides subsp. mycoides SC necessary to efficiently combat CBPP.

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With respect to localization, oligodendrogliomas are characterized by a marked preponderance of the cerebral hemispheres. Outside these typical sites, any tumor histopathologically reminiscent of oligodendroglioma a priori is likely to represent one of its morphological mimics, including clear cell ependymoma, neurocytoma, pilocytic astrocytoma or glioneuronal tumors. This is particularly relevant as several of the latter are in principle curable by surgery. Among extrahemispherical sites, bona fide oligodendroglioma - as characterized by loss of heterozygosity (LOH) of chromosome arms 1p and 19q - so far has not been documented to occur in the brain stem. Here, we report the case of a 55-year-old female patient with an anaplastic oligodendroglioma (WHO grade III) of the brain stem and cerebellum diagnosed by stereotactic biopsy and featuring combined LOH of 1p and 19q. A morphological peculiarity was a population of interspersed tumor giant cells, a phenomenon that has been referred to as polymorphous oligodendroglioma. Our findings confirm the notion that - although very infrequently - true oligodendrogliomas do occur in the infratentorial compartment.

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There are certain differences in how women and how men speak, and there are even more stereotypes. Thefocus of analysis is on how Flipa, a female character played by a man in the programme El hormiguero, is perceived by men and women, comparing a Spanish-speaking and a Swiss audience. The study consists of a quantitative and a qualitative analysis of a survey about Flipa’sperception. Formen,Flipa’s performance is more convincing than for women. Furthermore, the Swiss participants not only judge Flipa on the axis women-men, but here stereotypes about Spanish people also come into play.

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The FsrABC system of Enterococcus faecalis controls the expression of gelatinase and a serine protease via a quorum-sensing mechanism, and recent studies suggest that the Fsr system may also regulate other genes important for virulence. To investigate the possibility that Fsr influences the expression of additional genes, we used transcriptional profiling, with microarrays based on the E. faecalis strain V583 sequence, to compare the E. faecalis strain OG1RF with its isogenic mutant, TX5266, an fsrB deletion mutant. We found that the presence of an intact fsrB influences expression of numerous genes throughout the growth phases tested, namely, late log to early stationary phase. In addition, the Fsr regulon is independent of the activity of the proteases, GelE and SprE, whose expression was confirmed to be activated at all three time points tested. While expression of some genes (i.e., ef1097 and ef0750 to -757, encoding hypothetical proteins) was activated in late log phase in OG1RF versus the fsrB deletion mutant, expression of ef1617 to -1634 (eut-pdu orthologues) was highly repressed by the presence of an intact Fsr at entry into stationary phase. This is the first time that Fsr has been characterized as a negative regulator. The newly recognized Fsr-regulated targets include other factors, besides gelatinase, described as important for biofilms (BopD), and genes predicted to encode the surface proteins EF0750 to -0757 and EF1097, along with proteins implicated in several metabolic pathways, indicating that the FsrABC system may be an important regulator in strain OG1RF, with both positive and negative effects.

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Coronary heart disease (CHD) is the leading cause of death in the United States. Recently, renin-angiotensin system (RAS) was found associated with atherosclerosis formation, with angiotensin II inducing vascular smooth muscle cell growth and migration, platelet activation and aggregation, and stimulation of plasminogen activator inhibitor-1. Angiotensin II is converted from angiotensin I by angiotensin I-converting enzyme (ACE) and this enzyme is mainly genetically determined. The ACE gene has been assigned to chromosome 17q23 and an insertion/deletion (I/D)polymorphism has been characterized by the presence/absence of a 287 bp fragment in intron 16 of the gene. The two alleles form three genotypes, namely, DD, ID and II and the DD genotype has been linked to higher plasma ACE levels and cell ACE activity.^ In this study, the association between the ACE I/D polymorphism and carotid artery wall thickness measured by B-mode ultrasound was investigated in a biracial sample, and the association between the gene and incident CHD was investigated in whites and if the gene-CHD association in whites, if any, was due to the gene effect on atherosclerosis. The study participants are from the prospective Atherosclerosis Risk in Communities (ARIC) Study, including adults aged 45 to 65 years. The present dissertation used a matched case-control design for studying the associations of the ACE gene with carotid artery atherosclerosis and an unmatched case-control design for the association of the gene with CHD. A significant recessive effect of the D allele on carotid artery thickness was found in blacks (OR = 3.06, 95% C.I: 1.11-8.47, DD vs. ID and II) adjusting for age, gender, cigarette smoking, LDL-cholesterol and diabetes. No similar associations were found in whites. The ACE I/D polymorphism is significantly associated with coronary heart disease in whites, and while stratifying data by carotid artery wall thickness, the significant associations were only observed in thin-walled subgroups. Assuming a recessive effect of the D allele, odds ratio was 2.84 (95% C.I:1.17-6.90, DD vs. ID and II) and it was 2.30 (95% C.I:1.22-4.35, DD vs. ID vs. II) assuming a codominant effect of the D allele. No significant associations were observed while comparing thick-walled CHD cases with thin-walled controls. Following conclusions could be drawn: (1) The ACE I/D polymorphism is unlikely to confer appreciable increase in the risk of carotid atherosclerosis in US whites, but may increases the risk of carotid atherosclerosis in blacks. (2) ACE I/D polymorphism is a genetic risk factor for incident CHD in US whites and this effect is separate from the chronic process of atherosclerosis development. Finally, the associations observed here are not causal, since the I/D polymorphism is in an intron, where no ACE proteins are encoded. ^

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During the development of the somatic genome from the Paramecium germline genome the bulk of the copies of ∼45 000 unique, internal eliminated sequences (IESs) are deleted. IES targeting is facilitated by two small RNA (sRNA) classes: scnRNAs, which relay epigenetic information from the parental nucleus to the developing nucleus, and iesRNAs, which are produced and used in the developing nucleus. Why only certain IESs require sRNAs for their removal has been enigmatic. By analyzing the silencing effects of three genes: PGM (responsible for DNA excision), DCL2/3 (scnRNA production) and DCL5 (iesRNA production), we identify key properties required for IES elimination. Based on these results, we propose that, depending on the exact combination of their lengths and end bases, some IESs are less efficiently recognized or excised and have a greater requirement for targeting by scnRNAs and iesRNAs. We suggest that the variation in IES retention following silencing of DCL2/3 is not primarily due to scnRNA density, which is comparatively uniform relative to IES retention, but rather the genetic properties of IESs. Taken together, our analyses demonstrate that in Paramecium the underlying genetic properties of developmentally deleted DNA sequences are essential in determining the sensitivity of these sequences to epigenetic control.

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[Verf. Albert Cohn]

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Depuis que les glaciers fondent, la glace libère des objets hautement intéressants. C’est ainsi qu’en été 2003 une promeneuse a ramassé un objet qui a été remis au Service archéologique du canton de Berne. La datation au C14 révéla qu’il s’agit d’un fragment de carquois en écorce de bouleau datant du Néolithique Final. Depuis l’été 2004, le Service archéologique du canton de Berne étudie le site du Schnidejoch,un col situé à 2756 mètres d’altitude entre l’Oberland bernois et le Valais, et a ainsi pu récolter plus de 300 objets . L’éventail des objets découverts s’étend de bouts de vêtements préhistoriques en cuir et raphia à des épingles en bronze et des clous de souliers romains en passant par un carquois et des flèches. Les découvertes du Schnidejoch sont les plus anciennes du genre jamais faites dans les Alpes.