| 1. |
- Albano, Amanda, et al.
(författare)
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Echocardio-variability - Low and high frequency beat-to-beat variability in echocardiographic signals
- 2013
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Ingår i: Computing in Cardiology 2013. - 9781479908844 ; , s. 767-770
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Konferensbidrag (refereegranskat)abstract
- Measurement signals originating from the cardiovascular system are known to comprise oscillating components and beat-to-beat variability, e.g., heart-rate variability and blood pressure variability. In clinical echocardiographic procedures, typically only a few cardiac cycles are acquired. This pilot study analyses the beat-to-beat variability of echocardiographic variables (echocardio-variability) in minute long acquisitions.
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| 2. |
- Grönlund, Christer, 1975-, et al.
(författare)
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Significant beat-to-beat variability of E/e’ irrespective of respiration
- 2013
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Ingår i: International cardiovascular forum. - : Barcaray Publishing. - 2409-3424 .- 2410-2636. ; 1:2, s. 88-89
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Tidskriftsartikel (refereegranskat)abstract
- The E/e’ ratio is commonly used in Doppler echocardiographic examinations to estimate the pulmonary capillary wedge pressure. The rationale of using this ratio is to combine left ventricular (LV) filling (E) and relaxation (e’) velocities to indirectly assess left atrial pressure. However, the accuracy of this index has recently been questioned, particularly in patients with controlled heart failure. Likewise, the potential beat-to-beat variability of such measurements remains undetermined. The cardiovascular system is subject to several oscillations with the potential of influencing LV function and its intra-cavitary pressures, hence measurements of its filling and relaxation velocities. The aim of this pilot study was to assess the beat-to-beat variability of the E/e’ ratio in one minute long examination in healthy subjects, and patients with various severity of amyloid heart disease. The results show that despite critical application of the standard echocardiographic recording recommendations, E/e’ beat-to-beat variability was 36 % (22 to 50%) in healthy subjects and 17 % (11-26%) in patients, and where the most severe amyloid heart disease had the least variability. Thus, clinical use of a single or few cardiac beats might not necessarily reflect an accurate ratio between the two velocities, and hence casts doubt over their diagnostic value.
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| 3. |
- Gustavsson, Sara, 1985, et al.
(författare)
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Linear Maximum Likelihood Regression Analysis For Untransformed Log-Normally Distributed Data
- 2012
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Ingår i: Open Journal of Statistics. - : Scientific Research Publishing, Inc.. - 2161-718X .- 2161-7198. ; 2:4, s. 389-400
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Tidskriftsartikel (refereegranskat)abstract
- Medical research data are often skewed and heteroscedastic. It has therefore become practice to log-transform data in regression analysis, in order to stabilize the variance. Regression analysis on log-transformed data estimates the relative effect, whereas it is often the absolute effect of a predictor that is of interest. We propose a maximum likelihood (ML)-based approach to estimate a linear regression model on log-normal, heteroscedastic data. The new method was evaluated with a large simulation study. Log-normal observations were generated according to the simulation models and parameters were estimated using the new ML method, ordinary least-squares regression (LS) and weighed least-squares regression (WLS). All three methods produced unbiased estimates of parameters and expected response, and ML and WLS yielded smaller standard errors than LS. The approximate normality of the Wald statistic, used for tests of the ML estimates, in most situations produced correct type I error risk. Only ML and WLS produced correct confidence intervals for the estimated expected value. ML had the highest power for tests regarding
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| 4. |
- Pennbrant, Sandra, 1967-, et al.
(författare)
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Mastering the professional role as a new graduate
- 2012
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Konferensbidrag (refereegranskat)abstract
- Professional development is a process that starts in education and continues through working life. To be a new graduated registered nurse has been described as difficult and tough. The healthcare organization, patients and nurses would all benefit if the professional development was smooth and supportive. The aim was to develop a model describing newly graduated registered nurses professional development during the first years of healthcare practice. To develop a model a constant comparative analysis was performed. Data consisted of written answers to an open question concerning what newly graduates perceived of particular significance to facilitate the transition between education and professional life. In this study the core concept constructed from data was mastering the professional role and was seen as a result of an ongoing process regarding the individual's experiences as well as relations with the surrounding environments. The analysis shows that the professional developmental process involves three interrelated sub-processes; Evaluating and re-evaluating educational experience, developing professional self-efficacy and developing clinical competence. These sub-processes are all influenced by six factors, social values and norms, the healthcare organization, nurse-management, coworkers, patients/relatives and private life situation. These factors affect nurse' professional development directly, indirectly or as mediating influences and can lead to various possible orientations. The result underlines the importance of knowing of how to develop the personal professional role within in a working life context inorder to experience to mastering the professional role. In this process the new registered nurses need support from both their nursing school and employer. This model will be the subject of further measurement and testing
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| 5. |
- Sernbo, Sandra, et al.
(författare)
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The tumour suppressor SOX11 is associated with improved survival among high grade epithelial ovarian cancers and is regulated by reversible promoter methylation
- 2011
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background: The neural transcription factor SOX11 has been described as a prognostic marker in epithelial ovarian cancers (EOC), however its role in individual histological subtypes and tumour grade requires further clarification. Furthermore, methylation-dependent silencing of SOX11 has been reported for B cell lymphomas and indicates that epigenetic drugs may be used to re-express this tumour suppressor, but information on SOX11 promoter methylation in EOC is still lacking. Methods: SOX11 expression and clinicopathological data was compared using chi(2) test in a cohort of 154 cases of primary invasive EOC. Kaplan-Meier analysis and the log rank test were applied to evaluate ovarian cancer-specific survival (OCSS) and overall survival (OS) in strata, according to SOX11 expression. Also, the methylation status of the SOX11 promoter was determined by sodium bisulfite sequencing and methylation specific PCR (MSP). Furthermore, the effect of ectopic overexpression of SOX11 on proliferation was studied through [3H]-thymidine incorporation. Results: SOX11 expression was associated with an improved survival of patients with high grade EOC, although not independent of stage. Further analyses of EOC cell lines showed that SOX11 mRNA and protein were expressed in two of five cell lines, correlating with promoter methylation status. Demethylation was successfully performed using 5'-Aza-2'deoxycytidine (5-Aza-dC) resulting in SOX11 mRNA and protein expression in a previously negative EOC cell line. Furthermore, overexpression of SOX11 in EOC cell lines confirmed the growth regulatory role of SOX11. Conclusions: SOX11 is a functionally associated protein in EOC with prognostic value for high-grade tumours. Re-expression of SOX11 in EOC indicates a potential use of epigenetic drugs to affect cellular growth in SOX11-negative tumours.
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| 6. |
- Suhr, Ole B., et al.
(författare)
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New Insights into the clinical evaluation of hereditary transthyretin amyloidosis patients : A single center’s experience
- 2012
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Ingår i: Degenerative Neurological and Neuromuscular Disease. - : Dove Press. - 1179-9900. ; 2012:2, s. 93-106
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Tidskriftsartikel (refereegranskat)abstract
- Over the last decade, new medical treatment modalities have emerged based on increased insights into amyloid formation. With the increased possibilities for treatment of amyloidosis caused by transthyretin (TTR) amyloid deposits comes the need for diagnostic procedures for early diagnosis and better tools to follow disease progression. This is of particular importance in clinical trials evaluating the efficacy of new treatments. Until recently, the treatment of TTR amyloidosis (ATTR) was based solely on liver transplantation, a procedure that has halted disease progression in many patients. Liver transplantation has been especially effective in patients under the age of 50 years carrying the TTR V30M mutation, whereas the outcome of the procedure has been variable for others, particularly elderly male patients and those carrying a non-V30M mutation. This review concentrates on new insights derived from our center's experience with liver transplantation, how to implement this experience in evaluation of new treatment modalities for ATTR, and how to facilitate early diagnosis of neuropathy with easily available diagnostic tools. Attention has focused on manifestations of the disease that involve the heart and the peripheral nervous system; change in peripheral nerve function has been the primary endpoint in two controlled clinical trials, one finished and one ongoing. New insights into the amyloid formation process and the lessons learned from liver transplantation give the opportunity to design potentially effective treatment modalities for ATTR. It appears reasonable to suspect that a combination of different treatment modalities may be required to treat the disease, and that different treatment regimes will be designed according to the phenotype of the disease. For the patients and their relatives there is now a solid foundation for optimism, with prospects of several effective medical treatment possibilities within the coming decade.
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| 7. |
- Zhao, Ying, et al.
(författare)
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Residual compromised myocardial contractile reserve after valve replacement for aortic stenosis
- 2012
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Ingår i: European Heart Journal Cardiovascular Imaging. - Oxford : Oxford University Press. - 2047-2404 .- 2047-2412. ; 13:4, s. 353-360
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Despite recovery of left ventricular (LV) function and morphology after aortic valve replacement (AVR) for aortic stenosis (AS), its relationship with exercise capacity remains unknown. Twenty-one AVR patients (age 61 +/- 12 years, 14 male) with normal ejection fraction (EF, 64 +/- 7%) and 21 age- and sex-matched controls (57 +/- 9 years, 10 male, EF 68 +/- 8%) were studied.Methods and results: All subjects performed semi-supine bicycle exercise and speckle tracking echocardiography (STE) study. Peak oxygen consumption (pVO(2)) was collected during semi-supine bicycle exercise. Systolic (GLSRs) and early diastolic (GLSRe) longitudinal strain rate using STE and Doppler echocardiographic parameters were measured at rest, submaximal, peak exercise, and 4 min after exercise. The two groups had comparable resting echocardiographic measurements. At peak exercise, pVO(2) was lower in patients than controls (18.5 +/- 4.5 vs. 22.1 +/- 4.3 L/min/kg, P < 0.05). GLSRs (0.98 +/- 0.28 vs. 1.55 +/- 0.30 1/s, P < 0.001), septal Sm (7.9 +/- 1.4 vs. 11.1 +/- 2.3 cm/s, P < 0.001) and their changes between rest and peak exercise (Delta GLSRs: 0.16 +/- 0.33 vs. 0.68 +/- 0.27 1/s, P < 0.001; Delta Sm 2.29 +/- 2.23 vs. 4.63 +/- 2.29 cm/s, P < 0.01) were significantly lower in patients than controls. There was no correlation between pVO(2) and any echocardiographic measurements in controls. In patients, pVO(2) correlated with peak exercise GLSRs (r = 0.60, P = 0.0007), septal Sm (r = 0.65, P = 0.002), and Em (r = 0.57, P = 0.009). In a multivariate model, peak exercise GLSRs (beta = 7.18, P = 0.03) was the only independent predictor of pVO(2) in the patients group.Conclusion: Exercise capacity is subnormal after AVR for AS, irrespective of normal LVEF suggesting residual compromised myocardial functional reserve.
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