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- Landerholm, Malin K, et al.
(författare)
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Characterization of novel structural features in the lipopolysaccharide of nondisease associated nontypeable Haemophilus influenzae
- 2004
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Ingår i: European Journal of Biochemistry. - : Wiley. - 0014-2956 .- 1432-1033. ; 271:5, s. 941-953
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Tidskriftsartikel (refereegranskat)abstract
- Nontypeable Haemophilus influenzae (NTHi) is a common commensal of the human upper respiratory tract and is associated with otitis media in children. The structures of the oligosaccharide portions of NTHi lipopolysaccharide (LPS) from several otitis media isolates are now well characterized but it is not known whether there are structural differences in LPS from colonizing, nondisease associated strains. Structural analysis of LPS from nondisease associated NTHi strains 11 and 16 has been achieved by the application of high-field NMR techniques, ESI-MS, ESI-MSn, capillary electrophoresis coupled to ESI-MS, composition and linkage analyses on O-deacylated LPS and core oligosaccharide material. This is the first study to report structural details on LPS from strains taken from the nasopharynx from healthy individuals. Both strains express identical structures and contain the common element of H. influenzae LPS, L-alpha-D-Hepp-(1-->2)-[PEtn-->6]-L-alpha-D-Hepp-(1-->3)-[beta-D-Glcp-(1 -->4)]-L-alpha-D-Hepp-(1-->5)-[PPEtn-->4]-alpha-Kdop-(2-->6)-lipid A, in which each heptose is elongated by a single hexose residue with no further oligosaccharide extensions. In the major Hex3 glycoform, the terminal Hepp residue (HepIII) is substituted at the O-2 position by a beta-D-Galp residue and the central Hepp residue (HepII) is substituted at O-3 by a alpha-D-Glcp residue. Notably, the strains express two phosphocholine (PCho) substituents, one at the O-6 position of alpha-D-Glcp and the other at the O-6 position of beta-D-Galp. Major acetylation sites were identified at O-4 of Gal and O-3 of HepIII. Additionally, both strains express glycine, and strain 11 also expresses detectable amounts of N-acetylneuraminic acid.
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| 2. |
- Schweda, Elke K H, et al.
(författare)
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Structural profiling of lipopolysaccharide glycoforms expressed by non-typeable Haemophilus influenzae : phenotypic similarities between NTHi strain 162 and the genome strain Rd
- 2003
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Ingår i: Carbohydrate Research. - 0008-6215 .- 1873-426X. ; 338:23, s. 2731-2744
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Tidskriftsartikel (refereegranskat)abstract
- Non-typeable Haemophihis influenzae (NTHi) is a significant cause of otitis media in children. We have employed single and multiple step electrospray ionization mass spectrometry (ESIMS) and NMR spectroscopy to profile and elucidate lipopolysaccharide (LPS) structural types expressed by NTHi strain 162, a strain obtained from an epidemiological study in Finland. ESIMS on O-deacylated LPS (LPS-OH) and core oligosaccharide (OS) samples of LPS provided information on the composition and relative abundance of glycoforms differing in the number of hexoses linked to the conserved inner-core element, L-alpha-D-Hepp-(1--> 2)-[PEtn --> 6]-L-alpha-D-Hepp-(1 --> 3)-L-alpha-D-Hepp-(1 --> 5)(.)[PPEtn --> 4]-alpha-Kdop-(2 --> 6)-Lipid A of H. influenzae LPS. The strain examined was found to elaborate Hex2 to Hex5 LPS glycoform populations having structures identical to those observed for H. influenzae strain Rd [Risberg, A.; Masoud, H.; Martin, A.; Richards, J.C.; Moxon, E.R.; Schweda, E.K.H. Eur. J Biochem. 1999, 261, 171-180], the strain for which the complete genome has been sequenced. In addition, sialyllactose-containing glycoforms previously identified in strain Rd as well as several NTHi strains, were identified as minor components. Multiple step tandem ESIMS (MS") on dephosphorylated and permethylated OS provided information on the arrangement of glycoses within the major population of glycoforms and on the existence of additional isomeric glycoforms. Minor Hex1 and Hex6 glycoforms were detected and characterized where the Hex6 glycoform was comprised of a dihexosamine-containing pentasaccharide chain attached at the proximal heptose residue of the inner-core unit. LPS structural motifs present in the NTHi strain 162 are expressed by a genetically diverse set of disease causing isolates, providing the basis for a vaccine strategy against NTHi otitis media.
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| 4. |
- Järhult, J, et al.
(författare)
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Outcome of hypocalcaemia after thyroidectomy treated only in symptomatic patients
- 2016
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Ingår i: British Journal of Surgery. - : Oxford University Press. - 0007-1323 .- 1365-2168. ; 103:6, s. 676-683
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Tidskriftsartikel (refereegranskat)abstract
- Background: Calcium supplementation has been proposed after bilateral thyroid surgery, either to all patients or to those with biochemical hypocalcaemia. It has also been suggested that supplementation aids parathyroid recovery and prevents permanent hypoparathyroidism. This single-centre study investigated the feasibility of a restrictive management of post-thyroidectomy hypocalcaemia.Methods: Serum calcium was checked before surgery, on postoperative day 1 (POD) 1, at a follow-up visit 6-8 weeks after surgery and after a minimum of 12 months in all patients. Regardless of serum calcium levels, patients with symptoms of hypocalcaemia were prescribed oral calcium supplementation (0·5-1·0 g twice daily) and asymptomatic patients were not. Asymptomatic patients were informed about hypocalcaemic symptoms and instructed to contact the surgical ward should symptoms appear.Results: Some 640 patients underwent bilateral thyroid surgery without previous or intentional simultaneous parathyroidectomy. A subnormal serum calcium level (below 2·15 mmol/l) was observed in 412 patients (64·4 per cent) on POD 1. By comparison, only 63 patients (9·8 per cent) experienced symptoms of hypocalcaemia in the postoperative period, all but one with a corresponding biochemical hypocalcaemia on POD 1. Calcium levels in all patients with asymptomatic postoperative hypocalcaemia recovered to normal without supplementation. Serum calcium was also normalized during follow-up in all symptomatic patients, except 22 (3·4 per cent) who became permanently hypoparathyroid. No patient without early hypocalcaemic symptoms developed permanent hypoparathyroidism.Conclusion: The proposed restrictive management of postoperative hypocalcaemia after bilateral thyroid surgery avoids unnecessary supplementation for most patients.
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| 5. |
- Landerholm, K., et al.
(författare)
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Should asymptomatic retrosternal goitre be left untreated? A prospective single-centre study
- 2014
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Ingår i: Scandinavian Journal of Surgery. - : Sage Publications. - 1457-4969 .- 1799-7267. ; 104:2, s. 92-95
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Tidskriftsartikel (refereegranskat)abstract
- Background and aims: Retrosternal goiter may cause symptoms of airway obstruction and dysphagia, but often it is asymptomatic and is increasingly detected incidentally with imaging investigations. Consensus has been reached that sternotomy is not necessary in most cases, as a collar incision normally suffices. Yet, surgery for retrosternal goiter is associated with more complications than cervical goiter. There is controversy over whether patients with asymptomatic retrosternal goiter should be operated. Proponents argue that retrosternal goiter may be a risk for thyroid cancer and may progress to later cause symptoms, although clear evidence is missing.Patients and methods: Between 1984 and 2012, 132 patients underwent surgery for benign retrosternal goiter. Preoperatively, the benign nature was clinically apparent and confirmed by fine needle cytology in most cases.Results: Sternotomy was required in only 4 of the 132 operations. Three patients died in the postoperative period. The risk of morbidity and mortality was 16.7% in 60 patients with compression symptoms and 13.9% in 72 patients without compression symptoms (P = 0.808). Histology revealed no case of unsuspected cancer.Conclusion: Surgery for retrosternal goiters involves a higher risk for complications than do cervical goiters, and the risk does not differ between patients with and without symptoms. This, and the fact that no patient in this study had unsuspected cancer, calls into question the rationale for surgery in patients with asymptomatic retrosternal goiter without suspected cancer.
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