| 1. |
- Almquist, Per Otto, et al.
(författare)
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Knee rotation in healthy individuals related to age and gender.
- 2012
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Ingår i: Journal of Orthopaedic Research. - : Wiley. - 1554-527X .- 0736-0266.
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Tidskriftsartikel (refereegranskat)abstract
- An external device ("the Rottometer") was especially designed to measure passive knee rotation in vivo. The device had earlier been evaluated with respect to it's validity and reliability. In the present study, we evaluated knee rotation in knee-healthy individuals and studied possible age and gender related differences. Measurements of total internal-external rotation were made at 90°, 60°, and 30° of flexion using 6 and 9 N m torques, as well as the examiner's apprehension of end-feel as displacing forces. The study group constituted of 120 healthy subjects (60 females and 60 males) with no prior or present knee disorders. The sample was divided into four age groups (15-30, 31-45, 46-60, and >60 years). The results showed no differences in knee rotation between the right and left knees or between the different flexion angles. The females showed 10-20% (p < 0.01) larger knee rotation than the males at all the three flexion angles and at all the three applied torques in all age-matched groups. In all age groups in both genders, the internal rotation accounted for 40-44% and the external for 56-60% of the total internal-external knee rotation. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.
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| 2. |
- Almquist, Per O, et al.
(författare)
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Measurements of knee rotation-reliability of an external device in vivo.
- 2011
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Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Knee rotation plays an important part in knee kinematics during weight-bearing activities. An external device for measuring knee rotation (the Rottometer) has previously been evaluated for validity by simultaneous measurements of skeletal movements with Roentgen Stereometric Analysis (RSA). The aim of this study was to investigate the reliability of the device. METHOD: The within-day and test-retest reliability as well as intertester reliability of the device in vivo was calculated. Torques of 3, 6 and 9 Nm and the examiner's apprehension of end-feel were used at 90°, 60° and 30° of knee flexion. Intraclass Correlation Coefficient 2,1 (ICC 2,1), 95% confidence interval (CI) of ICC and 95% CI between test trials and examiners were used as statistical tests. RESULT: ICC2,1 ranged from 0.50 to 0.94 at all three flexion angles at 6 and 9 Nm as well as end-feel, and from 0.22 to 0.75 at 3 Nm applied torque. CONCLUSION: The Rottometer was a reliable measurement instrument concerning knee rotation at the three different flexion angles (90°, 60° and 30°) with 6 and 9 Nm applied torques as well as the examiner's apprehension of end-feel. Three Nm was not a reliable torque. The most reliable measurements were made at 9 Nm applied torque.
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| 3. |
- af Klinteberg, Britt, et al.
(författare)
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Family psychosocial characteristics influencing criminal behaviour and mortality - possible mediating factors : a longitudinal study of male and female subjects in the Stockholm Birth Cohort
- 2011
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Ingår i: BMC Public Health. - : Springer Science and Business Media LLC. - 1471-2458. ; 11, s. 756-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Family psychosocial characteristics in childhood have been associated with children's development into criminal behaviour and mortality. This study explored these possible relationships and examined alcohol and/or drug use and mental problems as possible mediating factors, highlighting gender-specific patterns. Methods: Data from Swedish subjects born in 1953 (n = 14,294) from the Stockholm Birth Cohort study were examined. Several indicators of adverse family factors and individual problems were included in the present study. The information was derived from various data sources, covering different periods. Gender-specific associations with incidence of criminality (1966-1980) and mortality (1981-2009) were analysed using logistic regression. Furthermore, the population attributable fraction (PAF) was calculated for all variables in the fully adjusted models which were positively related to the outcome. Results: Overall incidence of criminality and mortality was (m/f 32.3/6.6) and (m/f 6.1/3.5), respectively. The results showed that all aspects of family psychosocial and individual problems studied were associated with criminality for both genders. Among males, individual problems seemed to partly mediate these relations, but the associations remained statistically significant. Interestingly, the PAF analysis revealed a reduction in criminality of 17.5% when individual problems with alcohol and/or drug use were considered. Among females, a significant impact of alcohol and/or drug use on the association between family psychosocial characteristics and subsequent criminality was obtained. Inclusion of father's occupational class only somewhat reduced the estimates for the genders. Concerning male mortality, father's alcohol abuse was significantly related to an increased risk. When individual criminality was accounted for, the association was substantially reduced but remained statistically significant. Among females, when adjusting for family psychosocial factors, only the association between parents' mental problems and females' mortality was significant. None of the individual problem variables managed to explain this association. Conclusions: Family psychosocial characteristics were associated with both subsequent criminal behaviour and mortality. These connections were partly explained by individual risk factors, especially by alcohol and/or drug use. The practical implications of the findings point to the importance of addressing the individual's alcohol and/or drug use in reducing criminal behaviour, which would also lower the mortality rates.
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| 4. |
- Almquist, H, et al.
(författare)
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Performance of simultaneous emission-transmission systems for attenuation-corrected SPEct: a method for validation applied to two camera systems
- 2001
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Ingår i: Nuclear Medicine Communications. - 1473-5628. ; 22:7, s. 759-766
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Tidskriftsartikel (refereegranskat)abstract
- Several commercially available systems for attenuation correction in single photon emission computed tomography (SPECT) based on a transmission scan have been introduced that vary in performance. A test procedure for attenuation correction in SPECT is described and applied to two principally different gamma camera systems (the Siemens Multispect 3 triple-headed system [3HS] and the ADAC Genesys Vertex double-headed system [2HS]). The test procedure was based on geometrically well-defined phantoms. A torso phantom was used to illustrate the attenuation correction methods. The test procedure can be used without detailed knowledge of or access to the algorithms used for attenuation correction. The influence on the transmission measurement of radioactivity in a phantom was higher for the 2HS than for the 3HS. The 3HS produced satisfactory attenuation maps and corrected emission count rates to a constant value independent of phantom density and size. With the 2HS, there was a progressive decrease in the correction of emission count rates with increasing phantom density, and about 30% lower corrected count rates in the large compared with the small phantom. A decrease in measured attenuation coefficients in the vicinity of an emission source was demonstrated in large but not small phantoms. A likely explanation is erroneous correction of downscatter into the transmission energy window. This study demonstrates the need for independent evaluation of systems for attenuation correction in SPECT.
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| 5. |
- Almquist, Helén, et al.
(författare)
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Quantitative SPECT by attenuation correction of the projection set using transmission data: evaluation of a method
- 1990
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Ingår i: European Journal Of Nuclear Medicine. - 1432-105X. ; 16:8-10, s. 587-594
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Tidskriftsartikel (refereegranskat)abstract
- A method for measuring attenuation coefficients in single-photon emission tomography (SPECT) is described and evaluated, together with a method for attenuation correction using these measured attenuation coefficients. Build-up, caused by scattered photons, is corrected for by a simple substitution in the algorithms. Transmission studies are performed with a 99mTc- or 57Co flood source, and emission phantom studies with 99mTc line sources. The method is evaluated with variable but well-defined phantoms. The result is accurate attenuation coefficients for different densities, dimensions and geometries, and an accuracy of corrected emission activities of better than +/- 10% in most cases. The present limitations of the method for attenuation correction are discussed.
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| 6. |
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| 7. |
- Almquist, Per Otto, et al.
(författare)
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Evaluation of an external device measuring knee joint rotation: an in vivo study with simultaneous Roentgen stereometric analysis.
- 2002
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Ingår i: Journal of Orthopaedic Research. - 1554-527X. ; 20:3, s. 427-432
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Tidskriftsartikel (refereegranskat)abstract
- An external device ("rottometer") specially designed to measure knee joint rotation was developed and evaluated with respect to its validity. Simultaneous measurements were made with the rottometer and Roentgen stereometric analysis (RSA) in five patients with implanted tantalum markers in the tibia and femur. Measurements of internal and external rotation were made at 90 degrees and 60 degrees of knee flexion using 3, 6 and 9 N m torques. The coefficients of determination (r2) between the results obtained with the rottometer and RSA were around 0.9 for the total rotation. The rottometer consistently overestimated the rotation by about 100% and this systematic error was most constant at 90 degrees flexion for the different torques. The magnitude of this error from soft tissue deformation as well as the rotatory movements in the hip, foot and ankle joints must be considered when using external devices to measure knee rotation in clinical studies. The most accurate registrations were found in 90 degrees flexion with 9 N m force (r2 = 0.94).
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| 8. |
- Almquist, Per Otto
(författare)
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Measurements of knee rotation in vivo - Development and evaluation of an external device
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of this work was to evaluate a newly developed measurement device, the Rottometer, for measuring knee rotation in different flexion angles with different applied torques, in order to establish the normal range of healthy knee rotation reference values and to study possible differences due to age and gender, as well as possible differences between patients with habitual dislocating patella (HDP) and healthy controls. The validity of the Rottometer was evaluated by simultaneous registrations with roentgen stereometric analysis (RSA) (paper I). The two methods showed high correlations concerning the total knee rotation at 90° and 60° of knee flexion angles with 3, 6 and 9 Nm applied torques. The Rottometer was also concluded to be a reliable measurement device concerning the one-week-apart and within day intra-tester as well as the inter-tester reliability at 90°, 60° and 30° with 6 and 9 Nm as well as the examiner’s apprehension of end-feel (paper II). In total, 120 knee healthy subjects (60 females and 60 males) equally distributed in four different age groups (15-30, 31-45, 46-60 and ≥ 61 years) were examined at 90°, 60° and 30° of knee flexion angles with 6 and 9 Nm applied torques as well as the examiner’s apprehension of end-feel (paper III). No differences were found concerning the different flexion angles, between the left and right knee or between the different age groups within the genders. However, the females showed a 10-20 % larger range of knee rotation than the males at all different flexion angles and applied torques. The knee rotation was also examined in 20 patients (15 females and 5 males) with HDP (paper IV). No differences were found between the affected and unaffected knees within the subjects. In accordance with the healthy reference population, the female subjects showed a 10-20 % significantly larger range of rotation than the male subjects in the HDP group, and no differences were found between the patients affected with HDP and age matched healthy controls.
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| 9. |
- Almquist, T., et al.
(författare)
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Lipid-lowering treatment and inflammatory mediators in diabetes and chronic kidney disease
- 2014
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Ingår i: European Journal of Clinical Investigation. - : Wiley. - 0014-2972 .- 1365-2362. ; 44:3, s. 276-284
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Tidskriftsartikel (refereegranskat)abstract
- Background: Inflammation may contribute to the high cardiovascular risk in diabetes mellitus (DM) and chronic kidney disease (CKD). Monocyte chemoattractant protein-1 (MCP-1) facilitates the recruitment of monocytes into atherosclerotic lesions and is involved in diabetic nephropathy. Interferon gamma (IFNγ) is important in atherosclerosis and increases the synthesis of chemokines including MCP-1. Lipid-lowering treatment (LLT) with statins may have anti-inflammatory effects, and ezetimibe cotreatment provides additional cholesterol lowering. Methods: After a placebo run-in period, the effects of simvastatin alone (S) or simvastatin + ezetimibe (S+E) were compared in a randomized, double-blind, cross-over study on inflammatory parameters. Eighteen DM patients with estimated glomerular filtration rate (eGFR) 15-59 mL/min × 1·73 m2 (CKD stages 3-4) (DM-CKD) and 21 DM patients with eGFR > 75 mL/min (DM only) were included. Results: At baseline, monocyte chemoattractant protein 1 (MCP-1) (P = 0·03), IFNγ (P = 0·02), tumour necrosis factor-α (TNFα) (P < 0·01) and soluble vascular adhesion molecule (sVCAM) (P = 0·001) levels were elevated in DM-CKD compared with DM-only patients. LLT with S and S+E reduced MCP-1 levels (P < 0·01 by anova) and IFNγ levels (P < 0·01) in DM-CKD patients but not in DM-only patients. Reductions were most pronounced with the combination treatment. Conclusions: DM patients with CKD stages 3-4 had increased inflammatory activity compared with DM patients with normal GFR. Lipid-lowering treatment decreased the levels of MCP-1 and IFNγ in DM patients with concomitant CKD, which may be beneficial with regard to the progression of both atherosclerosis and diabetic nephropathy.
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| 10. |
- Carlson, Per, 1967-, et al.
(författare)
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Are area-level effects just a proxy for school-level effects? Socioeconomic differences in alcohol consumption patterns among Swedish adolescents
- 2016
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Ingår i: Drug And Alcohol Dependence. - : Elsevier BV. - 0376-8716 .- 1879-0046. ; 166, s. 243-248
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Tidskriftsartikel (refereegranskat)abstract
- AimsAlthough recent studies have found significant variations in adolescent alcohol consumption across neighbourhoods, these investigations did not address another important context in adolescents’ lives: schools. The purpose of this study was to not only simultaneously assess variations in adolescent alcohol use and binge drinking at the city district level and the school level but also analyse whether any such variations could be ascribed to the socioeconomic characteristics of the examined city districts, schools, and students.DesignCross-sectional study.SettingStockholm, Sweden.ParticipantsNinth-grade students (n = 4349) attending schools (n = 75) located in the city districts of the Stockholm municipality (n = 14).MeasurementsTwo measures based on information regarding alcohol consumption were constructed: alcohol use (no or yes) and binge drinking among alcohol users (ranging from “very seldom” to “a few times a week”). A wide range of socioeconomic characteristics was included at the city district, school, and student levels. Alcohol use was analysed using mixed-effects logistic regression, whereas binge drinking among users was modelled using mixed-effects ordered logistic regression.FindingsThe results indicated that the school was more important than the city district in assessments of contextual variations in adolescent alcohol use in general and binge drinking in particular. Moreover, proportions of well-educated parents and high-performing students accounted for part of the school-level variation in alcohol use but not binge drinking.ConclusionsFailure to account for the school context may have caused past research to overestimate city district differences in alcohol consumption among adolescents.
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