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- Cluff, AH, et al.
(författare)
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Prolonged labour associated with lower expression of syndecan 3 and connexin 43 in human uterine tissue
- 2006
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Ingår i: Reproductive Biology and Endocrinology. - : Springer Science and Business Media LLC. - 1477-7827. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Prolonged labour is associated with greater morbidity and mortality for mother and child. Connexin 43 is a major myometrial gap junction protein found in human myometrium. Syndecan 3 seems to prevail in the human uterus among heparan sulphate proteoglycans, showing the most significant increase during labour. The aims of the present study were to investigate syndecan 3 and connexin 43 mRNA expressions and protein distributions in human uterine tissue during normal and prolonged labour. Methods: Uterine isthmic biopsies were collected from non-pregnant (n = 7), term pregnant women not in labour (n = 14), in normal labour (n = 7) and in prolonged labour (n = 7). mRNA levels of syndecan 3 and connexin 43 were determined by real time RT-PCR. The localization and expression were demonstrated by immunohistochemistry and confocal microscopy. Results: In women with prolonged labour, the mRNA expressions of syndecan 3 and Connexin 43 were considerably lower than the expression level at normal labour (p < 0.05). In term-pregnant tissue, the expression of syndecan 3 and connexin 43 did not differ significantly compared to nonpregnant and normal labour. The immunoreactivity of syndecan 3 was strong at normal labour, in contrast to prolonged labour, where both a weaker expression and an irregular distribution were detected. The immunoreactivity of connexin 43 increased until term and further stronger staining occurred at normal labour. At prolonged labour, the immunoreactivity was weaker and more unevenly distributed. At labour, a co-localization of syndecan 3 and connexin 43 could be demonstrated in the smooth muscle by confocal microscopy. Conclusion: The high expression of syndecan 3 and connexin 43 and their co-localization to the smooth muscle bundles during normal labour, together with the significant reduction in prolonged labour, may indicate a role for these proteins in the co-ordination of myometrial contractility.
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| 2. |
- Dahlqvist, Camilla, et al.
(författare)
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Comparing two methods to record maximal voluntary contractions and different electrode positions in recordings of forearm extensor muscle activity : refining risk assessments for work-related wrist disorders
- 2018
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Ingår i: Work. - : IOS Press. - 1051-9815. ; 59:2, s. 231-242
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Tidskriftsartikel (refereegranskat)abstract
- Background: Wrist disorders are common in force demanding industrial repetitive work. Visual assessment of force demands have a low reliability, instead surface electromyography (EMG) may be used as part of a risk assessment for work-related wrist disorders. For normalization of EMG recordings, a power grip (hand grip) is often used as maximal voluntary contraction (MVC) of the forearm extensor muscles. However, the test-retest reproducibility is poor and EMG amplitudes exceeding 100% have occasionally been recorded during work. An alternative MVC is resisted wrist extension, which may be more reliable.Objective: To compare hand grip and resisted wrist extension MVCs, in terms of amplitude and reproducibility, and to examine the effect of electrode positioning.Methods: Twelve subjects participated. EMG from right forearm extensors, from four electrode pairs, was recorded during MVCs, on three separate occasions.Results: The group mean EMG amplitudes for resisted wrist extension were 1.2-1.7 times greater than those for hand grip. Resisted wrist extension showed better reproducibility than hand grip.Conclusions: The results indicate that the use of resisted wrist extension is a more accurate measurement of maximal effort of wrist extensor contractions than using hand grip and should increase the precision in EMG recordings from forearm extensor muscles, which in turn will increase the quality of risk assessments that are based on these.
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| 3. |
- Dahlqvist, Camilla, et al.
(författare)
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Self-recordings of upper arm elevation during cleaning - comparison between analyses using a simplified reference posture and a standard reference posture
- 2018
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Ingår i: BMC Musculoskeletal Disorders. - : BMC. - 1471-2474. ; 19
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Tidskriftsartikel (refereegranskat)abstract
- Background To reduce ergonomic risk factors in terms of awkward and constrained postures and high velocities, it is important to perform adequate risk assessments. Technical methods provide objective measures of physical workload. These methods have so far mainly been used by researchers. However, if written instructions how to apply the sensors and how to adopt the reference posture are provided, together with triaxial accelerometers, it may be possible for employees to record their own physical workload. The exposure in terms of e.g. upper arm elevations could then easily be assessed for all workers in a workplace. The main aims of this study were: 1) to compare analyses for self-recording of upper arm elevation during work using a simplified reference posture versus using a standard reference posture, and 2) to compare the two reference postures.MethodsTwenty-eight cleaners attached an accelerometer to their dominant upper arm and adopted a simplified reference according to a written instruction. They were thereafter instructed by a researcher to adopt a standard reference. Upper arm elevations were recorded for 2 or 3 days. Each recording was analysed twice; relative to the simplified reference posture and relative to the standard reference posture. The group means of the differences in recorded upper arm elevations between simplified and standard reference analyses were assessed using Wilcoxon signed ranks test. Furthermore, we calculated the group mean of the differences between the simplified reference posture and the standard reference posture.ResultsFor arm elevation during work (50(th) percentile), the group mean of the differences between the two analyses was 0.2 degrees (range-7 - 10 degrees). The group mean of the differences between the two references was 9 degrees (range 1-21 degrees). The subjects were able to follow the instructions in the protocol and performed self-recording of upper arm elevation and velocity.ConclusionsThe small difference between the two analyses indicates that recordings performed by employees themselves are comparable, on a group level, with those performed by researchers. Self-recordings in combination with action levels would provide employers with a method for risk assessment as a solid basis for prevention of work-related musculoskeletal disorders.
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| 4. |
- Dahlqvist, Camilla, et al.
(författare)
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Validity of a small low-cost triaxial accelerometer with integrated logger for uncomplicated measurements of postures and movements of head, upper back and upper arms
- 2016
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Ingår i: Applied Ergonomics. - : Elsevier. - 0003-6870 .- 1872-9126. ; 55, s. 108-116
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Tidskriftsartikel (refereegranskat)abstract
- Repetitive work and work in constrained postures are risk factors for developing musculoskeletal disorders. Low-cost, user-friendly technical methods to quantify these risks are needed. The aims were to validate inclination angles and velocities of one model of the new generation of accelerometers with integrated data loggers against a previously validated one, and to compare meaurements when using a plain reference posture with that of a standardized one. All mean (n = 12 subjects) angular RMS-differences in 4 work tasks and 4 body parts were <2.5° and all mean median angular velocity differences <5.0 °/s. The mean correlation between the inclination signal-pairs was 0.996. This model of the new generation of triaxial accelerometers proved to be comparable to the validated accelerometer using a data logger. This makes it well-suited, for both researchers and practitioners, to measure postures and movements during work. Further work is needed for validation of the plain reference posture for upper arms.
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