| 1. |
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| 2. |
- Hughes, Joseph L, et al.
(författare)
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The Native Reaction Centre of Photosystem II: A New Paradigm for P680
- 2004
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Ingår i: Australian Journal of Chemistry. - 0004-9425. ; 57:12, s. 1179-1183
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Tidskriftsartikel (refereegranskat)abstract
- Low-temperature spectra of fully active (oxygen-evolving) Photosystem II (PSII) cores prepared from spinach exhibit well developed structure. Spectra of isolated sub-fragments of PSII cores establish that the native reaction centre is better structured and red-shifted compared to the isolated reaction centre. Laser illumination of PSII cores leads to efficient and deep spectral hole-burning. Measurements of homogeneous hole-widths establish excited-state lifetimes in the 40–300 ps range. The high hole-burning efficiency is attributed to charge separation of P680 in native PSII that follows reaction-centre excitation via ‘slow transfer’ states in the inner light-harvesting assemblies CP43 and CP47. The ‘slow transfer’ state in CP47 and that in CP43 can be distinguished in the hole-burning action spectrum and high-resolution hole-burning spectra. An important observation is that 685–700 nm illumination gives rise to efficient P680 charge separation, as established by QA− formation. This leads to a new paradigm for P680. The charge-separating state has surprisingly weak absorption and extends to 700 nm.
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| 3. |
- Shoenfeld, Yehuda, et al.
(författare)
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Features associated with epilepsy in the antiphospholipid syndrome
- 2004
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Ingår i: Journal of Rheumatology. - 0315-162X. ; 31:7, s. 1344-1348
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To assess the frequency of epilepsy in primary and secondary antiphospholipid syndrome (APS); to analyze the clinical and laboratory features characterizing those with epilepsy in a cohort of 538 patients with APS; and to find associated features that would suggest risk factors for epilepsy in APS. METHODS: We analyzed the clinical features of patients with APS who had epilepsy and compared them to the clinical features of non-epileptic APS patients. RESULTS: Of 538 APS patients, 46 (8.6%) had epilepsy. Epilepsy was more prevalent among APS secondary to systemic lupus erythematosus (SLE) compared to primary APS (13.7% vs 6%; p < 0.05). The patients with epilepsy had a higher prevalence of central nervous system (CNS) manifestations including focal ischemic events (strokes or transient ischemic events, 54.3% vs 24.6%; p < 0.0001) and amaurosis fugax (15.2% vs 4.9%; p < 0.05). APS patients with epilepsy had a higher frequency of valvular pathology (30.4% vs 14.6%; p < 0.01), thrombocytopenia (43.5% vs 25%; p < 0.05), and livedo reticularis (26.1% vs 11.5%; p < 0.01). The multivariate logistic regression analysis found CNS thromboembolic events as the most significant factor associated with epilepsy, with an odds ratio (OR) of 4.05 (95% confidence interval, CI: 2.05-8), followed by SLE (OR 1.4, 95% CI 1.2-4.7), and valvular vegetations (OR 2.87, 95% CI 1-8.27). CONCLUSION: Epilepsy is common in APS and most of the risk seems to be linked to vascular disease as manifested by extensive CNS involvement, valvulopathy, and livedo reticularis and to the presence of SLE. These factors, however, explain only part of the increased occurrence of epilepsy in APS and other causes such as direct immune interaction in the brain should be investigated.
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| 4. |
- Fahlke, Claudia, 1964, et al.
(författare)
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Rearing experiences and stress-induced plasma cortisol as early risk factors for excessive alcohol consumption in nonhuman primates
- 2000
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Ingår i: Alcoholism: Clinical and Experimental Research. - : Wiley. - 0145-6008 .- 1530-0277. ; 24, s. 644-650
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Tidskriftsartikel (refereegranskat)abstract
- Background: The purpose of this study was to assess the impact of early rearing and stress-induced rise of plasma cortisol collected during infancy as a biological predictors of adult alcohol consumption in nonhuman primates. Methods: Ninety-seven female and male rhesus macaques (Macaca mulatta) were investigated. They were reared for their first 6 months of life either without mothers or other adults but with constant access to same-aged peers (peer-reared), or as controls with their mothers (mother-reared). When subjects reached 6 months of age, they underwent a series of four sequential weeks of 4-day social separations. Blood was drawn 1 and 2 hr after initiation of the 4-day separation periods, and the plasma was assayed for plasma cortisol concentrations. When the subjects were young adults (approximately 50 months of age), they were tested for voluntary intake of alcohol for 1 hr per day, 4 days a week, during a period of 5 to 7 weeks under normal living conditions. Results: The social separation challenge increased infant plasma cortisol concentrations, with peerreared subjects exhibiting higher stress-induced cortisol concentrations than mother-reared animals. Subjects that responded to the social separation challenge with high cortisol levels consumed significantly more alcohol per kilogram of body weight as adults than subjects with a low cortisol response to the separation challenge, regardless of rearing condition. In addition, male and peer-reared subjects consumed significantly more alcohol than female and mother-reared subjects, respectively. Conclusions: These findings suggest that early rearing experiences, such as! adult absence, and high plasma cortisol concentrations early in life after a social separation stressor, are useful psychobiological predictors of future high alcohol consumption among nonhuman primates.
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| 5. |
- Hughes, Joseph L, et al.
(författare)
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Photoconversion of chlorophylls in higher-plant CP43 characterized by persistent spectral hole burning at 1.7 K.
- 2004
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Ingår i: Journal of Luminescence. - : Elsevier BV. - 0022-2313. ; 108:1-4, s. 131-136
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Tidskriftsartikel (refereegranskat)abstract
- The chorophyll-protein complex CP43 is a proximal-antenna subunit important for excitation energy transfers from peripheral light-harvesting antenna to the Photosystem II (PSII) reaction centre. We report persistent spectral hole burning at 1.7 K in the Qy(0,0) origin and Qy(1,0) vibrational satellite bands of chorophyll a (chl a) in CP43 isolated from higher plants. The isolated CP43 is known to possess two quasi-degenerate 'red' trap states. We find persistent hole burning in the primary trap exhibits a photoconversion property, with a photoproduct located well outside its inhomogeneous distribution. This photoconversion of trap chl a molecules also occurs with non-selective white light illumination. The contribution of the 'red' states to CP43 absorption is discussed.
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| 6. |
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| 7. |
- MacDonald, Patrick, et al.
(författare)
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Impaired glucose-stimulated insulin secretion, enhanced IP insulin tolerance and increased {beta}-cell mass in mice lacking the p110{gamma} isoform of PI3-kinase.
- 2004
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 145:9, s. 4078-4083
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Tidskriftsartikel (refereegranskat)abstract
- Phosphoinositide 3-kinase (PI3 kinase) has been implicated in G protein-coupled receptor regulation of pancreatic ß-cell growth and glucose-stimulated insulin secretion. The G protein-activated p110{gamma} isoform of PI3 kinase was detected in insulinoma cells, mouse islets, and human islets. In 7- to 10-wk-old mice, knockout of p110{gamma} reduced the plasma insulin response to ip glucose injection and impaired first and second phase glucose-stimulated insulin secretion from pancreata perfused ex vivo. The p110{gamma} –/– mice responded to preinjection with the glucagon-like peptide-1 receptor agonist exendin 4, such that plasma glucose and insulin responses to ip glucose injection were not different from wild types. Mice lacking p110{gamma} were not diabetic and were only slightly glucose intolerant (ip glucose injection) compared with wild types, in part due to enhanced responsiveness to insulin as determined by an ip insulin tolerance test. Despite severely reduced insulin secretion in these animals, the p110{gamma} –/– mice had greater pancreatic insulin content, and an increased ß-cell mass due to ß-cell hypertrophy. These surprising results suggest that the G protein-coupled p110{gamma} isoform of PI3 kinase is not central to the development or maintenance of sufficient ß-cell mass but positively regulates glucose-stimulated insulin secretion.
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| 8. |
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| 9. |
- Augustsson, Andreas, et al.
(författare)
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Solid electrolyte interphase on graphite Li-ion battery anodes studied by soft X-ray spectroscopy
- 2004
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Ingår i: Phys. Chem. Chem. Phys. ; 6, s. 4185-4189
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Tidskriftsartikel (refereegranskat)abstract
- We have measured X-ray absorption and emission near the C Is edge of graphite electrodes cycled in lithium-ion battery cells. Resonantly excited emission spectra of graphite electrodes exhibit features characteristic of both highly oriented pyrolytic graphite as well as polycrystalline graphite. Spectra of three electrodes cycled in two different electrolytes are presented and compared with spectra of the pristine electrode. A solid electrolyte interphase(SEI) was detected on the electrochemically cycled electrodes. By the use of selective excitation, resonant X-ray emission spectra of the SEI-species were obtained and compared to spectra of reference compounds. The SEI on the cycled graphite anode was shown to comprise lithium oxalate (Li2C2O4), lithium succinate (LiO2CCH2CH2CO2Li) and lithium methoxide (LiOCH3).
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| 10. |
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| 11. |
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| 12. |
- Bruton, Joseph D., et al.
(författare)
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Ryanodine receptors of pancreatic beta-cells mediate a distinct context-dependent signal for insulin secretion
- 2003
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Ingår i: The FASEB Journal. - : Wiley. - 0892-6638 .- 1530-6860. ; 17:2, s. 301-303
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Tidskriftsartikel (refereegranskat)abstract
- The ryanodine (RY) receptors in beta-cells amplify signals by Ca2+-induced Ca2+ release (CICR). The role of CICR in insulin secretion remains unclear in spite of the fact that caffeine is known to stimulate secretion. This effect of caffeine is attributed solely to the inhibition of cAMP-phosphodiesterases (cAMP-PDEs). We demonstrate that stimulation of insulin secretion by caffeine is due to a sensitization of the RY receptors. The dose-response relationship of caffeine-induced inhibition of cAMP-PDEs was not correlated with the stimulation of insulin secretion. Sensitization of the RY receptors stimulated insulin secretion in a context-dependent manner, that is, only in the presence of a high concentration of glucose. This effect of caffeine depended on an increase in [Ca2+]i. Confocal images of beta-cells demonstrated an increase in [Ca2+]i induced by caffeine but not by forskolin. 9-Methyl-7-bromoeudistomin D (MBED), which sensitizes RY receptors, did not inhibit cAMP-PDEs, but it stimulated secretion in a glucose-dependent manner. The stimulation of secretion by caffeine and MBED involved both the first and the second phases of secretion. We conclude that the RY receptors of beta-cells mediate a distinct glucose-dependent signal for insulin secretion and may be a target for developing drugs that will stimulate insulin secretion only in a glucose-dependent manner.
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| 13. |
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| 14. |
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| 15. |
- Fryzek, Jon P., et al.
(författare)
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Self-reported symptoms among women after cosmetic breast implant and breast reduction surgery
- 2001
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Ingår i: Plastic and Reconstructive Surgery. - : Ovid Technologies (Wolters Kluwer Health). - 0032-1052. ; 107:1, s. 206-213
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Tidskriftsartikel (refereegranskat)abstract
- A retrospective cohort study was performed in Sweden to evaluate the possibility that an individual symptom or constellation of illness symptoms related to silicone occurs in women after breast implant surgery. A random sample (n = 2500) of all women in the Swedish national implant registry who underwent breast augmentation surgery with alloplastic breast implants during the years 1965 through 1993 was compared with a sample (n = 3500) of women who underwent breast reduction surgery during the same period, frequency matched to the implant patients for age and calendar year at the time of surgery. In total, 65 percent of the breast implant patients (n = 1546) and 72 percent of the breast reduction patients (n = 2496) completed a self-administered questionnaire covering 28 rheumatologic and other symptoms and lifestyle and demographic factors. Practically all of the 28 symptoms inquired about were reported more often by women in the breast implant cohort, with 16 (57 percent) significantly more common in breast implant recipients. In contrast, few significant differences or consistent patterns were observed in the length of time since the implant and in the type (silicone or saline) or volume of the implant. Although women with breast implants report a multitude of symptoms more often than women who have breast reduction surgery, the lack of specificity and absence of dose-response relationships suggest that the excess of reported symptoms is not causally related to cosmetic implants.
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| 16. |
- Guo, J. H., et al.
(författare)
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The molecular structure of alcohol-water mixtures determined by soft-X-ray absorption and emission spectroscopy
- 2004
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Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 137-40:SI, s. 425-428
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Tidskriftsartikel (refereegranskat)abstract
- We have examined the influence of the intermolecular interaction on the local electronic structure by using X-ray absorption and emission spectra of liquid methanol, water, and their mixtures (in molar ratios of 9:1 and 7:3). We find a strong involvement of hydrogen bonding in the mixing of water and methanol molecules. The local electronic structure of water and methanol clusters, where water cluster is bridging within a 6-member open-ring structured methanol cluster, is separately determined. The experimental findings suggest an incomplete mixing of water-alcohol systems and a strong self- association between methanol chain and water cluster through hydrogen bonding. The enhancement of joint water-methanol open-ring structure owes the explanation to the loss of entropy of the aqueous solutions.
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| 17. |
- Hua, Jianyi, et al.
(författare)
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Oxi4503, a novel vascular targeting agent: effects on blood flow and antitumor activity in comparison to combretastatin A-4 phosphate.
- 2003
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Ingår i: Anticancer research. - 1791-7530. ; 23:2B, s. 1433-1440
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Tidskriftsartikel (refereegranskat)abstract
- Oxi4503, which is the diphosphate prodrug of combretastatin A1, is a novel vascular targeting agent from the combretastatin family. Another member of this family, Combretastatin A-4 phosphate (CA4P), is a well-characterized vascular targeting agent already being evaluated in clinical trials. The potential for tumor vascular targeting by Oxi4503 was assessed in a mouse system. This approach aims to shut down the established tumor vasculature, leading to the development of extensive tumor cell necrosis. The vascular effects of Oxi4503 were assessed in the s.c. implanted MDA-MB-231 adenocarcinoma and the MHEC5-T hemangio-endothelioma in SCID mice and in a range of normal tissues. Blood flow was measured by i.v. injection of fluorescence beads, while quantitative fluorescence microscopy was used to measure the spatial heterogeneity of blood flow in tumor sections. Oxi4503 induced the shutdown of tumor blood vessels in a dose-dependent pattern with an ED50 at 3 mg/kg in contrast to 43 mg/kg of CA4P. Quantitative fluorescence microscopy showed that Oxi4503 increased the spatial heterogeneity in tumor blood flow. Oxi4503 affected peripheral tumor regions less than central regions, although this was not as pronounced as seen with CA4P, where only central regions were affected. The vascular shutdown induced by administration of Oxi4503 at a dose of 6 mg/kg resulted in extensive cell loss 24 hours following treatment, which translated into a significant effect on tumor growth. Tumor growth was completely repressed at doses above 12.5 mg/kg of Oxi4503, while doses above 25 mg/kg showed tumor regression and even complete regression in some animals. These results are promising for the use of Oxi4503 as a tumor vascular targeting agent. Moreover the potent antitumor effect when administered as a single agent suggests a different activity profile than CA4P.
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| 18. |
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| 19. |
- Kanis, John A, et al.
(författare)
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A meta-analysis of prior corticosteroid use and fracture risk.
- 2004
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Ingår i: Journal of bone and mineral research. - 0884-0431 .- 1523-4681. ; 19:6, s. 893-9
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Tidskriftsartikel (refereegranskat)abstract
- The relationship between use of corticosteroids and fracture risk was estimated in a meta-analysis of data from seven cohort studies of approximately 42,000 men and women. Current and past use of corticosteroids was an important predictor of fracture risk that was independent of prior fracture and BMD. INTRODUCTION: The aims of this study were to validate that corticosteroid use is a significant risk factor for fracture in an international setting and to explore the effects of age and sex on this risk. MATERIALS AND METHODS: We studied 42,500 men and women from seven prospectively studied cohorts followed for 176,000 patient-years. The cohorts comprised the EPOS/EVOS study, CaMos, the Rotterdam Study, Dubbo Osteoporosis Epidemiology Study (DOES), and prospective cohorts at Sheffield, Rochester, and Gothenburg. The effect of ever use of corticosteroids, BMD, age, and sex on all fracture, osteoporotic fracture, and hip fracture risk alone was examined using Poisson regression in each cohort and for each sex. The results of the different studies were merged from the weighted beta coefficients. RESULTS: Previous corticosteroid use was associated with a significantly increased risk of any fracture, osteoporotic fracture, and hip fracture when adjusted for BMD. Relative risk of any fracture ranged from 1.98 at the age of 50 years to 1.66 at the age of 85 years. For osteoporotic fracture, the range of relative risk was 2.63-1.71, and for hip fracture 4.42-2.48. The estimate of relative risk was higher at younger ages, but not significantly so. No significant difference in risk was seen between men and women. The risk was marginally and not significantly upwardly adjusted when BMD was excluded from the model. The risk was independent of prior fracture. In the three cohorts that documented current corticosteroid use, BMD was significantly reduced at the femoral neck, but fracture risk was still only partly explained by BMD. CONCLUSION: We conclude that prior and current exposure to corticosteroids confers an increased risk of fracture that is of substantial importance beyond that explained by the measurement of BMD. Its identification on an international basis validates the use of this risk factor in case-finding strategies.
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| 20. |
- Lagerstedt, Jens, 1975-
(författare)
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Regulatory and Structural Properties of the High-Affinity Phosphate Acquisition System in Saccharomyces cerevisiae
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Inorganic phosphate is an essential nutrient required for the synthesis of many cellular components (e.g., nucleic acids, proteins, lipids and sugars), as well as for meeting metabolic needs (e.g., energy production and translocation). In the case of the unicellular yeast Saccharomyces cerevisiae, the presence of both high- and low-affinity phosphate transporters in the plasma membrane provides for adaptation to environmental variations. Of these systems, the high-affinity Pho84 transport system is the major phosphate transporter activated when the cells have limited access to external phosphate. This integral membrane protein belongs to the major facilitator superfamily (MFS) and possesses 12 predicted transmembrane domains. Activation of this and other proteins (e.g., extracellular phosphatases) involved in maintaining cellular phosphate homeostasis under conditions of limited availability of external phosphate is controlled primarily by transcriptional regulation. However, the presence of proteins indirectly or directly involved in phosphate transport by Pho84, including Gtr1, has been reported. The Gtr1 protein binds guanine nucleotides and probably functions as a molecular switch. The present thesis describes the regulated intracellular trafficking and degradation of Pho84 in response to phosphate, as well as to its non-hydrolysable and non-utilizable analog methylphosphonate. The involvement of the Gtr1 protein in high-affinity phosphate uptake has also been examined. Moreover, in vitro and in silico analyses of structural and functional aspects of both the Pho84 and Gtr1 proteins are presented and discussed.
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| 21. |
- Magnuson, Martin, et al.
(författare)
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Electronic-structure investigation of CeB6 by means of soft-x-ray scattering
- 2001
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 63:7, s. 075101-
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Tidskriftsartikel (refereegranskat)abstract
- The electronic structure of the heavy fermion compound CeB6 is probed by resonant inelastic soft-x-ray scattering using photon energies across the Ce 3d and 4d absorption edges. The hybridization between the localized 4f orbitals and the delocalized valence-band states is studied by identifying the different spectral contributions from inelastic Raman scattering and normal fluorescence. Pronounced energy-loss structures are observed below the elastic peak at both the 3d and 4d thresholds. The origin and character of the inelastic scattering structures are discussed in terms of charge-transfer excitations in connection to the dipole allowed transitions with 4f character. Calculations within the single-impurity Anderson model with full multiplet effects are found to yield consistent spectral functions to the experimental data.
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| 22. |
- Magnuson, Martin, et al.
(författare)
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Electronic structure investigation of CoO by means of soft x-ray scattering
- 2002
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 65:20, s. 205106-
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Tidskriftsartikel (refereegranskat)abstract
- The electronic structure of CoO is studied by resonant inelastic soft x-ray scattering spectroscopy using photon energies across the Co 2p absorption edges. The different energy-loss structures in the Raman scattering spectra are identified as due to d-d and charge-transfer excitations. For excitation energies close to the L3 resonance, the spectral features are dominated by quartet-quartet and quartet-doublet transitions of the 3d7 configuration. At excitation energies corresponding to the satellites in the Co 2p x-ray-absorption spectrum of CoO, the emission features are instead dominated by charge-transfer transitions to the 3d8L¯-1 final state. The spectra are interpreted and discussed with the support of simulations within the single-impurity Anderson model with full multiplet effects which are found to yield consistent spectral functions to the experimental data.
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| 23. |
- Michelson, David, et al.
(författare)
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Relapse prevention in pediatric patients with ADHD treated with atomoxetine: a randomized, double-blind, placebo-controlled study.
- 2004
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Ingår i: Journal of the American Academy of Child and Adolescent Psychiatry. - 0890-8567. ; 43:7, s. 896-904
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Attention-deficit/hyperactivity disorder (ADHD) is typically treated over extended periods; however, few placebo-controlled, long-term studies of efficacy have been reported. METHOD: In a global multicenter study, children and adolescents who responded to an initial 12-week, open-label period of treatment with atomoxetine, a nonstimulant treatment for ADHD, were randomized to continued atomoxetine treatment or placebo for 9 months under double-blind conditions. RESULTS: A total of 416 patients completed acute atomoxetine treatment and were randomized. At end point, atomoxetine was superior to placebo in preventing relapse defined as a return to 90% of baseline symptom severity (proportion relapsing: atomoxetine 65 of 292 [22.3%], placebo 47 of 124 [37.9%], p =.002). The proportion of patients with a 50% worsening in symptoms post-randomization was also lower on atomoxetine (atomoxetine 83 of 292 [28.4%], placebo 59 of 124 [47.6%], p <.001). Compared with patients in the placebo group, atomoxetine-treated patients had superior psychosocial functioning at end point. Discontinuations for adverse events were low in both groups, and tolerability was similar to that observed in acute treatment trials. CONCLUSIONS: In patients who responded favorably to 12 weeks of initial treatment, atomoxetine was superior to placebo in maintaining response for the ensuing 9 months. This result supports the value of maintenance treatment with atomoxetine in patients with ADHD who respond to initial treatment.
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| 24. |
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| 25. |
- Schiessling, J, et al.
(författare)
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Polarization-dependent angular photoelectron distribution of solid C-60
- 2003
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Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121 .- 1550-235X. ; 68:20
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Tidskriftsartikel (refereegranskat)abstract
- We present angle- and polarization-dependent photoelectron spectra of solid C-60 recorded over a large range of emission angles. The bands derived from the three highest molecular orbitals are very similar in their angular distribution and show a strong dependence on both light polarization direction and sample orientation. We show that a molecular emission pattern modified by solid-state effects accounts for the observations.
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