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| 2. |
- Fugelstad, A., et al.
(författare)
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Methadone maintenance treatment : the balance between life-saving treatment and fatal poisonings
- 2007
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Ingår i: Addiction. - : Wiley. - 0965-2140 .- 1360-0443. ; 102:3, s. 406-412
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To determine the total mortality related to the Stockholm methadone programme during the period 1988-2000, both the mortality related to the treatment and fatal methadone intoxications in the Stockholm area during the same period. Methods: The study comprised all individuals (n = 848) who had been in contact with the methadone programme in Stockholm during the study period, including those patients who had been discharged from treatment and those opiate users who had applied for but not received methadone treatment. All deaths that had been the subject of medico-legal examination at the Department of Forensic Medicine in Stockholm where methadone was found in blood or urine were also analysed during the same period. Results: The mortality was lower among those opiate users who remained in maintenance treatment and 91% of the deceased individuals had died due to natural causes, in most cases related to HIV or hepatitis C, acquired before admission to the programme. Those who had been discharged from methadone treatment had a 20 times higher risk of dying from unnatural causes compared to the patients who remained in treatment. The majority died due to heroin injections ('overdoses'). Eighty-nine cases of fatal methadone intoxication were found, but in only two of these cases was there evidence of leakage from maintenance treatment. Conclusion: The 'high threshold programme' is safe as long as the patients remain in treatment and there are very few deaths due to leakage from the programme. However, there is a high mortality among those discharged from the programme and only a minority of the heroin users in Stockholm had applied for treatment.
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| 3. |
- McLoughlin, D, et al.
(författare)
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Surface complexation of DNA with insoluble monolayers. Influence of divalent counterions
- 2005
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 21:5, s. 1900-1907
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Tidskriftsartikel (refereegranskat)abstract
- DNA interacts with insoluble monolayers made of cationic amphiphiles as well as with monolayers of zwitterionic lipids in the presence of divalent ions. Binding to dioctadecyldimethylammonium bromide (DODAB) or distearoyl-sn-glycero-3-phosphocholine (DSPC) monolayers in the presence of calcium is accompanied by monolayer expansion. For the positively charged DODAB monolayer, this causes a decrease of surface potential, while an increase is observed for the DSPC monolayers. Binding to dipalmitoyl-sn-glycero-3-phosphocholine preserves most of the liquid expanded-liquid condensed coexistence region. The liquid condensed domains adopt an elongated morphology in the presence of DNA, especially in the presence of calcium. The interaction of DNA with phospholipid monolayers is ion specific: the presence of calcium leads to a stronger interaction than magnesium and barium. These results were confirmed by bulk complexation studies.
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| 4. |
- Bengtsson, Magnus Wilhelm, 1977-
(författare)
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Effects of Orexins, Guanylins and Feeding on Duodenal Bicarbonate Secretion and Enterocyte Intracellular Signaling
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The duodenal epithelium secretes bicarbonate ions and this is regarded as the primary defence mechanism against the acid discharged from the stomach. For an efficient protection, the duodenum must also function as a sensory organ identifying luminal factors. Enteroendocrine cells are well-established intestinal “taste” cells that express signaling peptides such as orexins and guanylins. Luminal factors affect the release of these peptides, which may modulate the activity of nearby epithelial and neural cells.The present thesis considers the effects of orexins and guanylins on duodenal bicarbonate secretion. The duodenal secretory response to the peptides was examined in anaesthetised rats in situ and the effects of orexin-A on intracellular calcium signaling by human as well as rat duodenal enterocytes were studied in vitro.Orexin-A, guanylin and uroguanylin were all stimulants of bicarbonate secretion. The stimulatory effect of orexin-A was inhibited by the OX1-receptor selective antagonist SB-334867. The muscarinic antagonist atropine on the other hand, did not affect the orexin-A-induced secretion, excluding involvement of muscarinic receptors. Orexin-A induced calcium signaling in isolated duodenocytes suggesting a direct effect at these cells. Interestingly, orexin-induced secretion and calcium signaling as well as mucosal orexin-receptor mRNA and OX1-receptor protein levels were all substantially downregulated in overnight fasted rats compared with animals with continuous access to food. Further, secretion induced by Orexin-A was shown to be dependent on an extended period of glucose priming.The uroguanylin-induced bicarbonate secretion was reduced by atropine suggesting involvement of muscarinic receptors. The melatonin receptor antagonist luzindole attenuated the secretory response to intra-arterially administered guanylins but had no effect on secretion when the guanylins were given luminally. In conclusion, the results suggest that orexin-A as well as guanylins may participate in the regulation of duodenal bicarbonate secretion. Further, the duodenal orexin system is dependent on the feeding status of the animals.
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| 5. |
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| 6. |
- Deleu, Magali, et al.
(författare)
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Fengycin interaction with lipid monolayers at the air-aqueous interface - implications for the effect of fengycin on biological membranes
- 2005
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 1095-7103 .- 0021-9797. ; 283:2, s. 358-365
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we investigated the interaction of fengycin, a lipopeptide produced by Bacillus subtilis, with lipid monolayers using the Langmuir trough technique in combination with Brewster angle rnicroscopy. Thermodynamic analyses were performed to get further information about the mixing behavior and the molecular interactions between the two components. The effect of fengycin on the structural and morphological characteristics of DPPC monolayers, as a simple model of biological membranes, depends on the fengycin molar ratio. With a small proportion of fengycin (X-f less than or equal to 0.1), the compressibility of the monolayer is modified but the morphological characteristics of the DPPC are not significantly affected. At an intermediate molar ratio (0.1 < X-f less than or equal to 0.5), fengycin has a fluidizing effect on the DPPC monolayer by interacting partially with DPPC molecules. At higher molar ratio (X-f = 0.66), fengycin totally dissolves the ordered phase of the lipid. These results highlight the capacity of fengycin to perturb the DPPC organization and are discussed in relation to fengycin capacity to affect biological membranes. (C) 2004 Elsevier Inc. All rights reserved.
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| 7. |
- Hernelahti, M., et al.
(författare)
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Sudden cardiac death in young athletes: time for a Nordic approach in screening?
- 2008
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Ingår i: Scand J Med Sci Sports. - : Wiley. ; 18:2, s. 132-139
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Tidskriftsartikel (refereegranskat)abstract
- In 2005, the European Society of Cardiology published recommendations for cardiovascular screening in athletes. Discussion on whether screening is beneficial is ongoing. Recently, the first prospective results on effectiveness of screening in preventing sudden deaths were published from Italy. The results were supportive of screening, but did not provide conclusive evidence. Our suggestion for a Nordic approach on this issue is a directed cardiovascular examination initially involving elite athletes, because this is feasible with respect to the Nordic health care systems and the organization and logistics of elite competitive sports, but also because of the negative aspects of screening large populations. This directed cardiovascular examination would include personal and family history, clinical examination, and electrocardiography (ECG). Further examinations should thereafter be carried out in athletes with suggestive findings in the initial evaluation. The directed cardiovascular examination should be voluntary. It should be conducted at least once, with information on alarming symptoms (syncope, chest pain or dizziness during exercise) and heredity (sudden cardiac death or hereditary heart disease in near relatives) stressed to the athlete as indications for necessary check-ups in the future. The examination would also provide the athlete with an ECG recording, which is valuable as a reference at a later time.
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| 8. |
- Larsson, Marcus, et al.
(författare)
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An X-ray diffraction study of alterations in bovine lung surfactant bilayer structures induced by albumin.
- 2006
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Ingår i: Chemistry and Physics of Lipids. - : Elsevier BV. - 0009-3084. ; 144:2, s. 137-145
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Tidskriftsartikel (refereegranskat)abstract
- Lung surfactant (LS) is an extra-cellular lipid-protein system responsible for maintaining low surface tension in the lung and alveolar stability. Serum proteins cause dysfunction of this material, e.g. in adult respiratory distress syndrome (ARDS). BLES is a clinically used LS consisting of most of the lipids and associated proteins from bovine lung lavage. Aqueous phases of BLES at 30% and 70% hydration, with and without 5% by weight of bovine serum albumin (BSA), calculated on the amount of lipids, were studied using X-ray diffraction during cooling from 42 to 5 degrees C. The diffraction curves are consistent with a transition from a lamellar liquid crystalline phase to a gel phase transition at cooling in the interval 30-20 degrees C. The long-spacings correspond to a reduction of the bilayer thickness during this transition. The wide-angle region shows a peak at 4.1 angstrom below 25 degrees C, which is characteristic of the hexagonal chain packing of the gel phase. The perturbation of the bilayers by the presence of BSA seems to induce a significant decrease of the bilayer thickness. Calculations on the observed limits of swelling (taking place in the range 50-60%) indicate that BSA is closely associated with the BLES bilayers, probably due to electrostatic interaction with the cationic surfactant proteins SP-B and SP-C. This study show that the LS lipid structural organizations are extremely susceptible to small amounts of serum albumin, which may have implications in surfactant related lung disease and clinical applications of surfactant therapy. (c) 2006 Elsevier Ireland Ltd. All rights reserved.
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| 9. |
- Moglianetti, Mauro, et al.
(författare)
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Interaction of sodium dodecyl sulfate and high charge density comb polymers at the silica/water interface
- 2009
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Ingår i: Soft Matter. - : Royal Society of Chemistry (RSC). - 1744-6848 .- 1744-683X. ; 5:19, s. 3646-3656
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Tidskriftsartikel (refereegranskat)abstract
- The structures of interfacial layers formed from mixtures of comb polymers, comprising a high charge density cationic backbone and poly(ethylene oxide) (PEO) side-chains, with the anionic surfactant sodium dodecyl sulfate (SDS) at the silica/water interface, have been determined using neutron reflectivity measurements. The use of mixtures in which only the isotopic composition of the surfactant is changed has made it possible to determine the interfacial volume fraction profiles for both the polymer and the surfactant. For the polymer with 90% of the segments charged and 10% of the segments carrying PEO side-chains, there are four regimes of interfacial behavior with increasing surfactant composition of the bulk solution. First there is adsorption of surfactant to the polymer-covered surface, then, slightly above polymer charge stoichiometry, there is adsorption of near-neutral polymer/surfactant complexes followed by the adsorption of polymer/surfactant aggregates, with a well-defined internal structure. If the concentration of SDS is increased directly from below polymer charge stoichiometry to above the cmc, micelles or polymer/micelle complexes interact with the pre-existing polymer layer. Increasing the fraction of segments carrying PEO side-chains to 25% suppresses the formation of charge-neutral polymer/surfactant complexes at the interface. There is an increase in the adsorption of surfactant, which interacts with the pre-existing layer of polymers. This results in the surface aggregation of SDS and a swelling of the PEO side-chains from a mushroom to a brush-like configuration.
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| 10. |
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