| 1. |
- Engervall, K, et al.
(författare)
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Borreliosis as a cause of peripheral facial palsy: a multi-center study
- 1995
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Ingår i: ORL. - 0301-1569. ; 57:4, s. 202-206
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Tidskriftsartikel (refereegranskat)abstract
- Borreliosis is known to be a common cause of peripheral facial palsy in Stockholm and its vicinity. The aim of the present study was to investigate the frequency and characteristics of borreliosis among patients with peripheral facial palsy in different parts of Sweden. All serological tests were performed in one laboratory. Ten Swedish Ear Nose and Throat clinics participated in a prospective 1-year study of patients seeking medical attention for acute peripheral facial palsy. Twenty-eight (6%) out of totally 446 patients fulfilled the criteria for the diagnosis of borreliosis. The frequency varied between 1 and 16% and was highest along the southeast coast of Sweden whereas no case was reported from the northern part of the country. Borreliosis was more common among children with facial palsy than among adults. The infection occurred during all seasons although it appears to be less frequent during the spring months. Only a minority of the borrelial patients had a history of a preceding tick bite or erythema migrans. The fairly low overall frequency of this secondary stage of borreliosis in the study may be a result of better knowledge of the disease and earlier treatment of its early manifestations. In Sweden's endemic areas borreliosis is a common cause of peripheral facial palsy, and therefore all patients with facial palsy in these regions should be examined for borrelial infection.
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| 2. |
- Al-Karadaghi, Salam, et al.
(författare)
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Crystal structure of ferrochelatase: the terminal enzyme in heme biosynthesis
- 1997
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Ingår i: Structure. - 0969-2126. ; 5:11, s. 1501-1510
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The metallation of closed ring tetrapyrroles resulting in the formation of hemes, chlorophylls and vitamin B12 is catalyzed by specific enzymes called chelatases. Ferrochelatase catalyzes the terminal step in heme biosynthesis by inserting ferrous ion into protoporphyrin IX by a mechanism that is poorly understood. Mutations in the human gene for ferrochelatase can result in the disease erythropoietic protoporphyria, and a further understanding of the mechanism of this enzyme is therefore of clinical interest. No three-dimensional structure of a tetrapyrrole metallation enzyme has been available until now. RESULTS: The three-dimensional structure of Bacillus subtilis ferrochelatase has been determined at 1.9 A resolution by the method of multiple isomorphous replacement. The structural model contains 308 of the 310 amino acid residues of the protein and 198 solvent molecules. The polypeptide is folded into two similar domains each with a four-stranded parallel beta sheet flanked by alpha helices. Structural elements from both domains build up a cleft, which contains several amino acid residues that are invariant in ferrochelatases from different organisms. In crystals soaked with gold and cadmium salt solutions, the metal ion was found to be coordinated to the conserved residue His 183, which is located in the cleft. This histidine residue has previously been suggested to be involved in ferrous ion binding. CONCLUSIONS: Ferrochelatase seems to have a structurally conserved core region that is common to the enzyme from bacteria, plants and mammals. We propose that porphyrin binds in the identified cleft; this cleft also includes the metal-binding site of the enzyme. It is likely that the structure of the cleft region will have different conformations upon substrate binding and release.
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| 3. |
- Fridén, H, et al.
(författare)
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Cytochrome b558 of Bacillus subtilis
- 1988
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Ingår i: Cytochrome Systems : Molecular Biology and Bioenergetics - Molecular Biology and Bioenergetics. - 9781461290780 - 9781461319412 ; , s. 641-647
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Bokkapitel (refereegranskat)abstract
- The membranebound tricarboxylic acid cycle enzyme succinate dehydrogenase (SDH) is associated with a b-type cytochrome in many organisms. 1,2 The cytochrome b is often found in stoichiometric amounts in isolated succinate-ubiquinone oxidoreductase (complex II) from bovine heart,3Neurospora crassa,4Ascaris suum5 and plant6 mitochondria as well as in SDH complexes isolated from both Gram-negative and Gram-positive8,9 bacteria whereas yeast (Saccharomyces cerevisiae) apparently lacks this type of cytochrome.10
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| 4. |
- Hederstedt, Lars, et al.
(författare)
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Covalent binding of FAD to Bacillus subtilis succinate dehydrogenase
- 1987
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Ingår i: Flavins and Flavoproteins : Proceedings of the Ninth International Symposium, Atlanta, Georgia, U. S. A. June 7-12, 1987 - Proceedings of the Ninth International Symposium, Atlanta, Georgia, U. S. A. June 7-12, 1987. - 3110109506 - 0899253067 ; , s. 729-736
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Konferensbidrag (refereegranskat)
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| 5. |
- Lachonius, Maria, 1962, et al.
(författare)
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Young adult patients' experience of living with mechanical circulatory support: A phenomenological hermeneutical study.
- 2019
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Ingår i: Nursing open. - : Wiley. - 2054-1058. ; 6:2, s. 651-658
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Tidskriftsartikel (refereegranskat)abstract
- To describe young adult patients' experiences of living with a mechanical circulatory support (MSC) as a bridge to heart transplantation and impact of self-efficacy.A qualitative and explorative interview study.Eight interviews with adult participants were conducted and analysed using the phenomenological hermeneutical method.An overall theme, "Navigating from helplessness to feeling strong in the new reality," and three themes were identified: "Feeling homeless in a changed reality" describes the experience of suddenly falling ill and the loneliness caused by the disease; "Finding my own inner resources" shows that the interviewees found the strength to fight for their lives and began to regain control of their situation; and "Adapting to my new reality" describes the importance of finding strength from others and being able to see MCS as a friend providing respite from the disease. Self-efficacy beliefs play a significant role in the process that the participants went through.
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| 6. |
- Svensson, B., et al.
(författare)
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Bacillus subtilis CtaA is a heme-containing membrane proteininvolved in heme A biosynthesis
- 1994
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Ingår i: Journal of Bacteriology. - : American Society for Microbiology. - 0021-9193 .- 1098-5530. ; 176:21, s. 6663-6671
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Tidskriftsartikel (refereegranskat)abstract
- Heme A is a prosthetic group of many respiratory oxidases. It is synthesized from protoheme IX (heme B) seemingly with heme O as a stable intermediate. The Bacillus subtilis ctaA and ctaB genes are required for heme A and heme O synthesis, respectively (B. Svensson, M. Lubben, and L. Hederstedt, Mol. Microbiol. 10:193-201, 1993). Tentatively, CtaA is involved in the monooxygenation and oxidation of the methyl side group on porphyrin ring D in heme A synthesis from heme B. B. subtilis ctaA and ctaB on plasmids in both B. subtilis and Escherichia coli were found to result in a novel membrane-bound heme-containing protein with the characteristics of a low-spin b type cytochrome. It fan be reduced via the respiratory chain, and in the reduced state it shows light absorption maxima at 428, 528, and 558 nm and the or-band is split. Purified cytochrome isolated from both B. subtilis and E. coli membranes contained one polypeptide identified as CtaA by amino acid sequence analysis, about 0.2 mol of heme B per mol of polypeptide, and small amounts of heme A.
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| 7. |
- Waldeck, A. Reginald, et al.
(författare)
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Electron paramagnetic resonance studies of succinate:ubiquinone oxidoreductase from Paracoccus denitrificans : Evidence for a magnetic interaction between the 3Fe-4S cluster and cytochrome b
- 1997
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Ingår i: Journal of Biological Chemistry. - : Elsevier BV. - 1083-351X .- 0021-9258.
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Tidskriftsartikel (refereegranskat)abstract
- Electron paramagnetic resonance (EPR) studies of succinate:ubiquinone oxidoreductase (SQR) from Paracoccus denitrificans have been undertaken in the purified and membrane-bound states, Spectroscopic ''signatures'' accounting for the three iron-sulfur clusters (2Fe-2S, 3Fe-4S, and 4Fe-4S), cytochrome b, flavin, and protein-bound ubisemiquinone radicals have been obtained in air-oxidized, succinate-reduced, and dithionite-reduced preparations at 4-10 K. Spectra obtained at 170 K in the presence of excess succinate showed a signal typical of that of a flavin radical, but superimposed with another signal. The superimposed signal originated from two bound ubisemiquinones, as shown by spectral simulations, Power saturation measurements performed on the air-oxidized enzyme provided evidence for a weak magnetic dipolar interaction operating between the oxidized 3Fe-4S cluster and the oxidized cytochrome b. Power saturation experiments performed on the succinate- and dithionite-reduced forms of the enzyme demonstrated that the 4Fe-4S cluster is coupled weakly to both the 2Fe-2S and the 3Fe-4S clusters, Quantitative interpretation of these power saturation experiments has been achieved through redox calculations. They revealed that a spin-spin interaction between the reduced 3Fe-4S cluster and the cytochrome b (oxidized) may also exist. These findings form the first direct EPR evidence for a close proximity (less than or equal to 2 nm) of the high potential 3Fe-4S cluster, situated in the succinate dehydrogenase part of the enzyme, and the low potential, low spin b-heme in the membrane anchor of the enzyme.
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