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H Bergström

Publications and source records attributed to H Bergström.

At least 19 recordsLinked to original sources
PubMed1990

Energy-transfer dynamics in three light-harvesting mutants of Rhodobacter sphaeroides: a picosecond spectroscopy study.

Picosecond absorption spectroscopy has been used to investigate energy-transfer dynamics within the LH1 and LH2 light-harvesting complexes of three mutants of Rhodobacter sphaeroides. We demonstrate that both complexes are inhomogeneous; each contains a specialized pigment pool which absorbs maximally at a longer wavelength. Within LH2 (mutant NF57), Bchl850 transfers energy to Bchl870 in 39 +/- 9 ps; within LH1 (mutants M21 and M2192), energy is transferred from Bchl875 to Bchl896 in 22 +/- 4 and 35 +/- 5 ps, respectively. Examination of the decay of induced absorption anisotropy indicates that each of these specialized pools exists in a state which is highly organized with respect to the remainder of the pigments. Such an arrangement may facilitate and direct energy migration toward the reaction center.

Energy Transfer↗
PubMed1989

Endometrial sampling using the Mi Mark procedure as a primary routine: first year's experience.

This study reports on the Mi Mark technique as a primary method of endometrial sampling in routine practice. The experience gained during the first year was evaluated with regard to diagnostic accuracy and acceptability. In total, 736 patients were examined using either the Mi Mark technique or dilatation and curettage (D&C). In the pre-menopausal and post-menopausal women, in the study group, 11% and 30%, respectively, of the Mi Mark specimens proved too scanty for evaluation. In women aged over 60 the proportion of specimens that were inadequate for diagnosis was around 60% and the Mi Mark technique was not therefore considered to be suitable for use in this age group. If the latter group is excluded, the Mi Mark procedure could replace D&C in 47% of cases. Where the sampling material obtained was inadequate a secondary D&C was performed, following which an atrophic endometrium was usually found, although endometrial cancers were detected in 2 cases. Thus, an inadequate specimen obtained by means of the Mi Mark helix did not exclude the possibility of endometrial malignancy. When questioned, 8% of the patients stated that they considered the pain associated with the examination to be severe. On the other hand, 93% were prepared to undergo another Mi Mark procedure if necessary. The Mi Mark technique was considered to be adequate in terms of both acceptability and accuracy provided a D&C was performed in cases where the Mi Mark specimen was inadequate for evaluation.

Biopsy↗
PubMed1988

Quantification of urinary incontinence in elderly women with the 48-hour pad test.

The ability of 34 elderly women (79 +/- 6 years, range 71-95 years) with urinary incontinence to perform the 48-h perineal pad test in their home environment was investigated. The mean involuntary urinary loss during the 48-h observation period was 80 +/- 88 g (range (2-411 g). Thirty patients successfully compared the two perineal pad systems commercially available in Sweden (LIC and Mölnlycke). Twelve women considered the systems to be equivalent. Thirteen women preferred the Mölnlycke system while five women preferred the LIC system. There was a good correlation between the patients own weighing of the pads and control weighings at the clinic, performed on a precision weight scale (LIC: n = 15, r = 0.99; Mölnlycke: n = 15, r = 0.99). The 48-h perineal pad test performed in the patients home environment should have a given place in the investigation of urinary incontinence amongst elderly women.

Aged↗
PubMed1975

Renographic evaluation of renal excretion in hydronephrosis of pregnancy.

The functional significance of renographic delay in excretion observed in connection with chiefly unilateral "physiologic" hydronephrosis of pregnancy was analyzed in 10 cases, The delay was found to be entirely or predominantly due to the reservoir effect of the dilated urinary tract. A moderate reduction of urinary flow on the affected side was suggested to contribute to the impairment in only 3 of the 10 cases. Interpretation of the degree of urinary obstruction as judged by renography should be cautious. This applies especially to the assessment of complete obstruction, which should be diagnosed only after considering the reservoir effect of the dilated tract.

Female↗