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K Petersson

Publications and source records attributed to K Petersson.

44 records · Page 3Linked to original sources
PubMed1978

Structural studies of Shigella flexneri O-antigens.

The structures of the O-antigens of all known serotypes and subserotypes of Shigella flexneri have been reinvestigated. The results support the assumption that these antigens are composed of a basic tetrasaccharide repeating unit (1), to which alpha-D-glucopyranosyl and/or O-acetyl groups are attached at different positions. Leads to 3)-beta-D-GlcNAcp-(1 leads to 2)-alpha-L-Rhap-(1 leads to 2)-alpha-L-Rhap-(1 leads to 3)-alpha-L-Rhap-(1 leads to The immunological determinants responsible for O-factors I, II, IV, V and 7, 8 contain alpha-D-gluco-pyranosyl groups, the locations of which have been determined. O-Factor 6 is due to O-acetyl groups, linked to O-2 of the 3-substituted alpha-L-rhamnopyranosyl residue in unit 1 and O-factor III seems to be due to the same groups. The chemical natures of the determinants responsible for O-factors 4 and 3, 4 are still obscure. The structural studies indicate that the immunological classification of Sh. flexneri serotypes and subserotypes, as regards these O-factors, may need revision.

Carbohydrates↗
PubMed1977

Structural studies of the Shigella flexneri variant X, type 5 a and type 5 b O-antigens.

Previous studies of different Shigella flexneri O-antigens indicate that their O-specific region is composed of oligosaccharide repeating units containing a basic tetrasaccharide structure, to which alpha-D-glucopyranosyl groups and O-acetyl groups may be attached to different positions. Structural studies of O-antigens from variant X, type 5a and type 5b lend further support to this assumption. These antigens contain terminal alpha-D-glucopyranosyl groups, one each per repeating unit in X and 5a, two in 5b. The location of these groups in the repeating unit has been determined.

Carbohydrates↗
PubMedDate not supplied

Metabolism of methylmercury in rabbits and hamsters.

The metabolism of 203Hg-labeled methylmercury chloride (MeHg) has been studied in rabbits and hamsters. Rabbits were administered 1.6 mumols MeHgCl/kg bw intravenously, and hamsters 40 mumols/kg bw orally. Urine and feces were collected daily and groups of four animals killed after 1 h, 1 d, or 7 d. The concentration of 203Hg in blood, liver, kidney, spleen, lung, heart, and brain was determined by gamma counting. In both animal species, the clearance of 203Hg in the brain was slower than in other tissues. In the rabbits the brain 203Hg concentration increased during the whole experimental period. Rabbits excreted 203Hg primarily in feces (about 20% of the dose within 1 wk), and much less in urine (less than 2%). In contrast, hamsters very efficiently excreted 203Hg in urine (50% in 1 wk). The fecal excretion was similar to that of the rabbits. Separation of inorganic Hg and MeHg in urine from hamsters by ion exchange chromatography showed that about 90% of the urinary 203Hg was excreted as MeHg. These findings show that rabbits and hamsters are interesting experimental animal systems for studying the metabolism of MeHg.

Animals↗
PubMedDate not supplied

Nocturnal hypoxaemia and cor pulmonale in severe chronic lung disease.

The relation between daytime and nocturnal hypoxaemia on one hand and right ventricular failure (RVF) and hypertrophy (RVH) on the other was studied in 21 patients with severely reduced ventilatory capacity. RVH was assessed by myocardial scintigraphy, vector cardiography and echocardiography. Seven patients had suffered from acute RVF at least once. They had lower vital capacity and PaO2 and higher PaCO2 than patients without a history of RVF. They also had a more severe nocturnal hypoxaemia. They did not, however, have more severe RVH than patients without a history of RVF. Blood gases during daytime were not related to RVH. Oxygen saturation during sleep had a weak inverse relationship to RVH determined with scintigraphy, but not with the other methods. Nocturnal hypoxaemia was closely related to hypoxaemia and hypercapnia during daytime. A difference between daytime PaO2 and PaCO2 less than 2 kPa could with reasonable accuracy identify patients with nocturnal hypoxaemia.

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