| 3971. |
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| 3972. |
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| 3973. |
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| 3974. |
- Syeda, Baquer M., et al.
(författare)
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9-BBN as a convenient protecting group in functionalisation of hydroxylysine
- 2004
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Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020. ; 60:26, s. 5571-5
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Tidskriftsartikel (refereegranskat)abstract
- 9-BBN was used for regioselective protection of the α-amino and α-carboxyl groups of (5R)-5-hydroxy--lysine. The resulting 9-BBN complex was then employed in transformations such as N-Cbz protection, azido transfer, O-glycosylation, and O-silylation. Further manipulations led to improved methods for preparation of hydroxylysine and galactosylated hydroxylysine building blocks, suitable for direct use in peptide synthesis under standard Fmoc conditions.
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| 3975. |
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| 3976. |
- Sze, C C, et al.
(författare)
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In vivo and in vitro effects of integration host factor at the DmpR-regulated sigma(54)-dependent Po promoter.
- 2001
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Ingår i: Journal of Bacteriology. - 0021-9193 .- 1098-5530. ; 183:9
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Tidskriftsartikel (refereegranskat)abstract
- Transcription from the Pseudomonas CF600-derived sigma(54)-dependent promoter Po is controlled by the aromatic-responsive activator DmpR. Here we examine the mechanism(s) by which integration host factor (IHF) stimulates DmpR-activated transcriptional output of the Po promoter both in vivo and in vitro. In vivo, the Po promoter exhibits characteristics that typify many sigma(54)-dependent promoters, namely, a phasing-dependent tolerance with respect to the distance from the regulator binding sites to the distally located RNA polymerase binding site, and a strong dependence on IHF for optimal promoter output. IHF is shown to affect transcription via structural repercussions mediated through binding to a single DNA signature located between the regulator and RNA polymerase binding sites. In vitro, using DNA templates that lack the regulator binding sites and thus bypass a role of IHF in facilitating physical interaction between the regulator and the transcriptional apparatus, IHF still mediates a DNA binding-dependent stimulation of Po transcription. This stimulatory effect is shown to be independent of previously described mechanisms for the effects of IHF at sigma(54) promoters such as aiding binding of the regulator or recruitment of sigma(54)-RNA polymerase via UP element-like DNA. The effect of IHF could be traced to promotion and/or stabilization of open complexes within the nucleoprotein complex that may involve an A+T-rich region of the IHF binding site and promoter-upstream DNA. Mechanistic implications are discussed in the context of a model in which IHF binding results in transduction of DNA instability from an A+T-rich region to the melt region of the promoter.
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| 3977. |
- Sze, Chun Chau, et al.
(författare)
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Integration of global regulation of two aromatic-responsive sigma(54)-dependent systems : a common phenotype by different mechanisms
- 2002
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Ingår i: Journal of Bacteriology. - : American Society for Microbiology. - 0021-9193 .- 1098-5530. ; 184:3, s. 760-770
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Tidskriftsartikel (refereegranskat)abstract
- Pseudomonas-derived regulators DmpR and XylR are structurally and mechanistically related sigma(54)-dependent activators that control transcription of genes involved in catabolism of aromatic compounds. The binding of distinct sets of aromatic effectors to these regulatory proteins results in release of a repressive interdomain interaction and consequently allows the activators to promote transcription from their cognate target promoters. The DmpR-controlled Po promoter region and the XylR-controlled Pu promoter region are also similar, although homology is limited to three discrete DNA signatures for binding sigma(54) RNA polymerase, the integration host factor, and the regulator. These common properties allow cross-regulation of Pu and Po by DmpR and XylR in response to appropriate aromatic effectors. In vivo, transcription of both the DmpR/Po and XylR/Pu regulatory circuits is subject to dominant global regulation, which results in repression of transcription during growth in rich media. Here, we comparatively assess the contribution of (p)ppGpp, the FtsH protease, and a component of an alternative phosphoenolpyruvate-sugar phosphotransferase system, which have been independently implicated in mediating this level of regulation. Further, by exploiting the cross-regulatory abilities of these two circuits, we identify the target component(s) that are intercepted in each case. The results show that (i) contrary to previous speculation, FtsH is not universally required for transcription of sigma(54)-dependent systems; (ii) the two factors found to impact the XylR/Pu regulatory circuit do not intercept the DmpR/Po circuit; and (iii) (p)ppGpp impacts the DmpR/Po system to a greater extent than the XylR/Pu system in both the native Pseudomonas putida and a heterologous Escherichia coli host. The data demonstrate that, despite the similarities of the specific regulatory circuits, the host global regulatory network latches onto and dominates over these specific circuits by exploiting their different properties. The mechanistic implications of how each of the host factors exerts its action are discussed.
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| 3978. |
- Säfström, Daniel, et al.
(författare)
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Task requirements influence sensory integration during grasping in humans.
- 2004
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Ingår i: Learning & memory (Cold Spring Harbor, N.Y.). - : Cold Spring Harbor Laboratory. - 1072-0502 .- 1549-5485. ; 11:3, s. 356-363
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Tidskriftsartikel (refereegranskat)abstract
- The sensorimotor transformations necessary for generating appropriate motor commands depend on both current and previously acquired sensory information. To investigate the relative impact (or weighting) of visual and haptic information about object size during grasping movements, we let normal subjects perform a task in which, unbeknownst to the subjects, the object seen (visual object) and the object grasped (haptic object) were never the same physically. When the haptic object abruptly became larger or smaller than the visual object, subjects in the following trials automatically adapted their maximum grip aperture when reaching for the object. This adaptation was not dependent on conscious processes. We analyzed how visual and haptic information were weighted during the course of sensorimotor adaptation. The adaptation process was quicker and relied more on haptic information when the haptic objects increased in size than when they decreased in size. As such, sensory weighting seemed to be molded to avoid prehension error. We conclude from these results that the impact of a specific source of sensory information on the sensorimotor transformation is regulated to satisfy task requirements.
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| 3979. |
- Sävenstedt, Stefan, 1950-, et al.
(författare)
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Being present in a distant room : A study of the qualitative aspects of teleconsultations with older people in a nursing home
- 2004
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Ingår i: Qualitative Health Research. - : Sage Publications. - 1049-7323 .- 1552-7557. ; 14:8, s. 1046-1057
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Tidskriftsartikel (refereegranskat)abstract
- In a telecare project in Northern Sweden, videophones have been used to facilitate teleconsultations between nurses and elders at a nursing home. The authors designed this study to elucidate qualities in the communication in the professional encounter between nurses and elders assisted by nursing staff in the teleconsultations. They interviewed 2 registered nurses and 5 nursing staff members with long experience of using videophones in the telecare project, out of 20 staff members, and analyzed them using a phenomenological-hermeneutic method. In a comprehensive interpretation, teleconsultations could be understood as glimpses of the experience of being in the other’s room with a feeling of providing nursing presence. This was attained when aspects such as familiarity, safety, transparency, and interest were promoted.
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| 3980. |
- Söderberg, Stig, 1950-, et al.
(författare)
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Childhood sexual abuse predicts poor outcome seven years after parasuicide
- 2004
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Ingår i: Social Psychiatry and Psychiatric Epidemiology. - : Springer Science and Business Media LLC. - 0933-7954 .- 1433-9285. ; 39:11, s. 916-920
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is substantial empirical research linking borderline personality disorder with prolonged mental instability and recurrent suicidality. At the same time, a growing body of observations links borderline personality disorder to sexual abuse and other forms of abuse and trauma in childhood. The aim of this study was to investigate among patients admitted for parasuicide the predictive value for outcome 7 years after the parasuicide of a diagnosis of borderline personality disorder compared to the predictive value of a history of childhood sexual abuse.Methods: Semi-structured interviews were conducted at the time of the index parasuicide, with follow-up interviews 7 years later. In addition, information was collected from medical records at the psychiatric clinic. A logistic regression analysis was used to assess the specific influence of the covariates borderline personality disorder, gender and reported childhood sexual abuse on the outcome variables.Results: Univariate regression analysis showed higher odds ratios for borderline personality disorder, female gender and childhood sexual abuse regarding prolonged psychiatric contact and repeated parasuicides. A combined logistic regression model found significantly higher odds ratios only for childhood sexual abuse with regard to suicidal ideation, repeated parasuicidal acts and more extensive psychiatric support.Conclusion: The findings support the growing body of evidence linking the characteristic symptoms of borderline personality disorder to childhood sexual abuse, and identify sexual abuse rather than a diagnosis of borderline personality disorder as a predictor for poor outcome after a parasuicide. The findings are relevant to our understanding and treatment of parasuicide patients, especially those who fulfil the present criteria for borderline personality disorder.
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