1. |
- Blomberg, Lars G., et al.
(author)
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Solar windmagnetosphere-ionosphere coupling : an event study based on Freja data
- 2004
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In: Journal of Atmospheric and Solar-Terrestrial Physics. - : Elsevier BV. - 1364-6826 .- 1879-1824. ; 66:5, s. 375-380
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Journal article (peer-reviewed)abstract
- Freja data are used to study the relative contributions from the high-latitude (reconnection/direct entry) and low-latitude (viscous interaction) dynamos to the cross-polar potential drop. Convection streamlines which are connected to the high-latitude dynamo may be identified from dispersed magnetosheath ions not only in the cusp/cleft region itself but also several degrees poleward of it. This fact, together with Freja's orbital geometry allows us to infer the potential drop from the high-latitude dynamo as well as to obtain a lower limit to the potential drop from the low-latitude dynamo for dayside Freja passes. All cases studied here are for active magnetospheric conditions. The Freja data suggest that under these conditions at least one third of the potential is generated in the low-latitude dynamo. These observations are consistent with earlier observations of the potential across the low-latitude boundary layer if we assume that the low-latitude dynamo region extends over several tens of Earth radii in the antisunward direction along the tail flanks, and that the majority of the potential drop derives from the sun-aligned component of the electric field rather than from its cross-boundary component, or equivalently, that the centre of the dynamo region is located quite far down tail. A possible dynamo geometry is illustrated.
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2. |
- Callréus, Torbjörn, et al.
(author)
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The influence of lithium on the antidiuretic effect of desmopressin.
- 2002
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In: Journal of Pharmacy and Pharmacology. - 0022-3573. ; 54:9, s. 1279-1285
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Journal article (peer-reviewed)abstract
- The objective of this study was to investigate the graded influence from lithium on the antidiuretic effects of desmopressin. Eight healthy male subjects participated in this open, randomised cross-over study with two periods comprising 6 days each. For each subject, one of the study days (6th day) was preceded by a period of lithium treatment. On the study days the subjects were orally water loaded to achieve a state of overhydration with a high urine flow rate. When a steady-state diuresis was achieved after approximately 2 h, 0.396 microg of desmopressin was administered intravenously as a bolus injection. An indirect-response model, where desmopressin was assumed to inhibit the elimination of response, was fitted to the urine osmolarity data. The effects of the independent variables, Uflow(baseline) (baseline urine flow rate), R0 (baseline osmolarity) and serum lithium concentration, on IC50 (concentration producing 50% of the maximum inhibition) could be expressed by multiple linear regression. In conclusion, we found that an indirect-response model can be a useful tool in investigating and describing the pharmacodynamic interaction between drugs, in this particular case, between lithium and desmopressin.
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3. |
- Greiff, Lennart, et al.
(author)
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Absorption across the nasal airway mucosa in house dust mite perennial allergic rhinitis.
- 2002
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In: Clinical Physiology and Functional Imaging. - 1475-0961. ; 22:1, s. 55-57
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Journal article (peer-reviewed)abstract
- House dust mite allergens express protease activity and it has been suggested that this property has pathogenic effects by increasing airway absorption. In accordance, house dust mite allergens may increase mucosal permeability in vitro. The objective of the present study was to examine nasal absorption of desmopressin (1-deamino-8-D-arginine vasopressin) in patients with perennial house dust mite allergic rhinitis and in healthy subjects in vivo. Patients with perennial allergic rhinitis were examined after a 4-week treatment withdrawal period, when symptoms of allergic rhinitis occurred, and healthy subjects were examined together with the patients. Desmopressin (20 microg ml(-1)) was moved into the nasal cavity using a nasal pool-device that contained 15 ml fluid. The fluid was kept in the nasal cavity for 15 min and then recovered. Urine was collected for 24 h after the nasal administration and the urinary excretion of desmopressin was determined as an index of nasal absorption. The urinary excretion of desmopressin was 1148+/-535 pmol 24 h(-1) in patients with perennial house dust mite allergic rhinitis and 1012+/-291 pmol 24 h(-1) in healthy subjects. We conclude that nasal airway absorption of the 1067 Da peptide desmopressin is unaffected in perennial house dust mite allergic rhinitis compared with healthy subjects.
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4. |
- Kaaks, Rudolf, et al.
(author)
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Prospective study of IGF-I, IGF-binding proteins, and breast cancer risk, in Northern and Southern Sweden
- 2002
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In: Cancer Causes and Control. - 1573-7225 .- 0957-5243. ; 13:4, s. 307-316
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Journal article (peer-reviewed)abstract
- Objective: To examine the possible relationships of breast cancer risk to prediagnostic plasma levels of insulin; insulin-like growth factor-I (IGF-I); and IGF-binding proteins -1, -2, and -3. Methods: Within two prospective cohorts in Umea and Malmo we measured plasma concentrations of insulin, IGF-I, and IGFBPs for a total of 513 incident breast cancer cases and 987 matched controls. Results: Globally, risk was unassociated with levels of IGF-I, IGFBP-3, or IGF-I adjusted for IGFBP-3. When breaking down the analysis by subgroups of age at blood donation, an increase in risk was observed for increasing levels of IGF-I in women aged 55 or older, in the Umea cohort only (odds ratios of 1.00, 1.73, 1.76, 1.90; p(trend) = 0.05). This effect weakened, however, when the analysis was restricted to subjects who did not use exogenous hormones for the treatment of menopausal symptoms. Levels of IGF-I and IGFBP-3 were not related to risk in younger women, recruited before age 50, contrary to observations from previous studies. In a subcohort where blood samples had been collected after at least four hours of fasting, breast cancer risk showed no clear associations with levels of insulin, IGFBP-1, or IGFBP-2. Conclusions: Our results do not confirm earlier findings of an association of plasma IGF-I levels with breast cancer risk especially in young women, but suggest a possible association with postmenopausal breast cancer risk, possibly among ERT/HRT users only. Our results do not support the hypothesis that elevated plasma insulin levels, and reduced levels of IGFBP-1 and IGFBP-2, are associated with increased breast cancer risk.
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5. |
- Lethvall, Sven, 1967, et al.
(author)
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Tracheal double-lumen ventilation attenuates hypercapnia and respiratory acidosis in lung injured pigs.
- 2004
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In: Intensive care medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; 30:4, s. 686-92
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Journal article (peer-reviewed)abstract
- OBJECTIVE: Evaluation of ventilatory and circulatory effects with coaxial double-lumen tube ventilation for dead-space reduction as compared with standard endotracheal tube ventilation. DESIGN: Experimental study in a pig model of lung lavage induced acute lung injury. SETTING: University research laboratory. MEASUREMENTS AND RESULTS: Tidal volumes of 6, 8 and 10 ml/kg body weight with a set respiratory rate of 20 breaths per minute were used in a random order with both double-lumen ventilation and standard endotracheal tube ventilation. Measurements of ventilatory and circulatory parameters were obtained after steady state at each experimental stage. With a tidal volume of 6 ml/kg, PaCO(2) was reduced from 10.9 kPa (95% CI 9.0-12.9) with a standard endotracheal tube to 8.2 kPa (95% CI 7.0-9.4) with double-lumen ventilation. This corresponds to a reduction in carbon dioxide levels by 25%. At 6 ml/kg, pH increased from 7.17 (95% CI 7.09-7.24) with a standard endotracheal tube to 7.27 (95% CI 7.21-7.32) with double-lumen ventilation. Tracheal pressure was monitored continuously and no difference between single- or double-lumen ventilation was noted at corresponding levels of ventilation. There was no formation of auto-PEEP. Partial tube obstruction due to secretions was not observed during the experiments. CONCLUSIONS: Coaxial double-lumen tube ventilation is an effective adjunct to reduce technical dead space. It attenuates hypercapnia and respiratory acidosis in a lung injury pig model.
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6. |
- Lindgren, Sophie, 1971, et al.
(author)
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Effectiveness and side effects of closed and open suctioning: an experimental evaluation.
- 2004
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In: Intensive care medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; 30:8, s. 1630-7
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Journal article (peer-reviewed)abstract
- OBJECTIVE: To compare the effectiveness of closed system suctioning (CSS) and open system suctioning (OSS) and the side effects on gas exchange and haemodynamics, during pressure-controlled ventilation (PCV) or continuous positive airway pressure (CPAP). DESIGN: Bench test and porcine lung injury model. PARTICIPANTS: Twelve bronchoalveolar saline-lavaged pigs. SETTING: Research laboratory in a university hospital. INTERVENTIONS: In a mechanical lung, the efficacy of OSS and CSS with 12 and 14 Fr catheters were compared during volume-control ventilation, PCV, CPAP 0 or 10 cmH(2)O by weighing the suction system before and after aspirating gel in a transparent trachea. Side effects were evaluated in the animals with the same ventilator settings during suctioning of 5, 10 or 20 s duration. MEASUREMENTS AND RESULTS: Suctioning with 12 and 14 Fr catheters was significantly more efficient with OSS (1.9+/-0.1, 2.8+/-0.9 g) and with CSS during CPAP 0 cmH(2)O (1.8+/-0.2, 4.2+/-0.5 g) as compared to CSS during PCV (0.2+/-0.2, 0.8+/-0.3 g) or CPAP 10 cmH(2)O (0.0+/-0.1, 0.7+/-0.4 g), p<0.01 (means +/- SD). OSS and CSS at CPAP 0 cmH(2)O resulted in a marked decrease in SpO(2), mixed venous oxygen saturation and tracheal pressure, p<0.001, but the side effects were considerably fewer during CSS with PCV and CPAP 10 cmH(2)O, p<0.05. CONCLUSIONS: Irrespective of catheter size, OSS and CSS during CPAP 0 cmH(2)O were markedly more effective than CSS during PCV and CPAP 10 cmH(2)O but had worse side effects. However, the side effects lasted less than 5 min in this animal model. Suctioning should be performed effectively when absolutely indicated and the side effects handled adequately.
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8. |
- Lukanova, Annekatrin, et al.
(author)
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Nonlinear relationship of insulin-like growth factor (IGF)-I and IGF-I/IGF-binding protein-3 ratio with indices of adiposity and plasma insulin concentrations (Sweden).
- 2002
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In: Cancer Causes and Control. - 0957-5243 .- 1573-7225. ; 13:6, s. 509-516
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Journal article (peer-reviewed)abstract
- OBJECTIVE: In this study we test the hypothesis of a nonlinear relationship of IGF-I with indices of body fat such as body mass index (BMI), insulin, and leptin.METHODS: The controls used in three case-control cancer studies nested in the Northern Sweden Health and Disease Cohort, were combined for this analysis. Measurements of plasma IGF-I, IGFBP-3, insulin, and leptin were available for 445 men and 391 women.RESULTS: In both men and women we found the highest mean IGF-I levels in subjects with BMI between 24 and 26. IGF-I concentrations decreased toward BMI < or = 20 and BMI > 30 in men; however, the results for women did not reach statistical significance. The molar ratio of IGF-I/IGFBP-3 showed a similar profile to that of IGF-I, although much less pronounced. The observed peak mean IGF-I levels in the second quintiles of insulin and leptin in men supported these findings. No significant variation of mean IGF-I levels across quintiles of insulin and leptin were observed in women.CONCLUSIONS: The results of this study provide evidence that IGF-I plasma concentrations vary substantially over a wide range of body weight and that the relationship is nonlinear.
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10. |
- Lundin, B, et al.
(author)
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Munchausen syndrome by proxy - a literature review and Swedish case histories
- 2001
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In: Läkartidningen. - 0023-7205 .- 1652-7518. ; 98:19, s. 2302-
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Journal article (peer-reviewed)abstract
- Munchausen syndrome by proxy (MSbP) is a potentially lethal form of child abuse. Mortality rates around 10 percent have been reported. A knowledge of the characteristics of MSbP is needed in order to reveal the diagnosis and to handle the management correctly. Swedish experience is in accordance with international reports.
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