| 1. |
- Almquist, Martin, et al.
(author)
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Reproductive history, lifestyle factors and season as determinants for serum calcium concentrations in women.
- 2008
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In: Scandinavian Journal of Clinical & Laboratory Investigation. - : Informa UK Limited. - 1502-7686 .- 0036-5513. ; 68, s. 777-785
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Journal article (peer-reviewed)abstract
- Objective. Serum calcium concentrations have been associated with the risk of malignant disease, especially breast cancer. Thus, determinants of serum calcium concentrations, with special regard to risk factors of breast cancer, are of great interest. Material and methods. Previous studies have either been small or they have not focused on reproductive factors. The present study examined serum calcium concentrations in relation to reproductive history, selected lifestyle factors and screening season in a large population-based cohort study comprising 8,114 women. ANOVA followed by the Bonferroni t-test were used for comparison of means, and logistic regression and multiple regression analysis were used to test associations. Results. Serum calcium concentrations were lower in hormone replacement therapy users versus non-users (2.321 mmol/L versus 2.364; p<0.001) and in users of oral contraceptives versus non-users (2.304 versus 2.348; p<0.001). They were higher in peri-/postmenopausal versus premenopausal women (2.357 versus 2.319; p<0.001). Overweight and obese women had higher mean calcium concentrations (2.350 and 2.355) than women with body mass index between 20 and 25 (2.342; p<0.001). Serum calcium concentrations were higher in spring and autumn than in winter (2.352 and 2.353 versus 2.343; p = 0.002). Both younger (40-45 years) (2.334; p = 0.001) and older age groups (>55 years) (2.363; p<0.001) had higher mean calcium concentrations compared to those of women aged 45-50 years (2.320), even when adjusting for menopausal status, suggesting that age has an independent influence on calcium concentrations. Conclusions. It is concluded that reproductive factors such as menopausal status, use of oral contraceptives or hormone-replacement therapy, and age, BMI and season are associated with serum calcium concentrations.
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| 2. |
- Carlsson, Christian J., et al.
(author)
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An evaluation of the interference of hydroxycobalamin with chemistry and co-oximetry tests on nine commonly used instruments
- 2011
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In: Scandinavian Journal of Clinical & Laboratory Investigation. - : Informa UK Limited. - 1502-7686 .- 0036-5513. ; 71:5, s. 378-386
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Journal article (peer-reviewed)abstract
- The administration of hydroxocobalamin (OHCob), alone or with sodium thiosulfate, is a standard therapy for cyanide poisoning. OHCob is a red chromophore, and its interference with co-oximetric and colorimetric laboratory measurements has been evaluated in a few conflicting reports. The interference of OHCob was investigated in samples spiked with 10 different concentrations of OHCob (0-1500 mg/L). The concentration of 73 different analytes was measured using nine different analysers (ABL 800 Flex, Advia 1800, Advia Centaur Xp, Architect ci8200, Immulite 2500, Konelab 30i, Modular Analytics SWA, Synchron LX 20 and Vitros 5.1). All instruments yielded some results that were affected by OHCob at concentrations equivalent to a single therapeutic dose. Of the 73 different analytes, 64% showed interference on at least one instrument. Of all 187 tests performed, 47% were biased with more than 10%. Interference was generally limited to photometric assays, whereas immunological and ion-selective electrode measurements were unaffected. OHCob present in the blood after treatment for cyanide poisoning interfered with many laboratory assays in an unpredictable way, making some results invalid. Some affected tests are important in the treatment of cyanide poisoning. The interference is not solely due to wavelength, but also to chemical interaction. Without delaying the administration of OHCob, blood should, preferably, be drawn in advance, or, at least, the laboratory should be informed about the OHCob treatment. If the laboratory receives OHCob-containing samples, methods and instruments should be selected to minimize bias, and the manufacturer of the OHCob should recommend relevant precautions to customers in the package insert.
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| 3. |
- Larsson, A, et al.
(author)
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Calculation of glomerular filtration rate expressed in mL/min from plasma cystatin C values in mg/L
- 2004
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In: Scandinavian Journal of Clinical & Laboratory Investigation. - : Informa UK Limited. - 1502-7686 .- 0036-5513. ; 64:1, s. 25-30
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Journal article (peer-reviewed)abstract
- The Cockcroft-Gault formula is often used to calculate the glomerular filtration rate (GFR) from plasma creatinine results. In Sweden this calculation is not usually done in the laboratory, but locally in the wards. These manual calculations could cause erroneous results. In several studies plasma cystatin C has been shown to be superior to plasma creatinine for estimation of GFR. One limitation of using cystatin C as a GFR marker is that there is no conversion formula transforming cystatin C expressed as mg/L to GFR expressed as mL/min. In this study plasma creatinine and cystatin C were compared with iohexol clearance. A stronger correlation (p<0.0001) was found between cystatin C and iohexol clearance (r(2) =0.91) than between creatinine and iohexol clearance (r(2) =0.84). From the correlation data a formula was calculated to convert cystatin C expressed as mg/L to GFR (mL/min). The formulas y=77.24x -1.2623 (Dade Behring cystatin C calibration) or y=99.43x -1.5837 (DakoCytomation cystatin C calibration) are used to calculate GFR expressed in mL/min from the cystatin C value in mg/L and both results are reported to the referral doctor. These formulas can provide the clinicians with reliable and readily available GFR data based on single measurements of cystatin C concentrations.
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| 4. |
- Sahlin, K. Barbara, et al.
(author)
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Short-term effect of pharmacologically induced alterations in testosterone levels on common blood biomarkers in a controlled healthy human model
- 2020
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In: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 80:1, s. 25-31
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Journal article (peer-reviewed)abstract
- Testosterone deficiency in males is associated with serious comorbidities such as cardiovascular disease, diabetes type two, and also an increased risk of premature death. The pathogenetic mechanism behind this association, however, has not yet been clarified and is potentially bidirectional. The aim of this clinical trial was to gain insight into the short-term effect of changes in testosterone on blood analytes in healthy young men. Thirty healthy young male volunteers were recruited and monitored in our designed human model. Blood sampling was performed prior to and 3 weeks after pharmacological castration with a gonadotropin-releasing hormone antagonist. Subsequently, testosterone replacement with 1000 mg testosterone undecanoate was given and additional blood samples were collected 2 weeks later. The alterations in the levels of 37 routine biomarkers were statistically analysed. Eight biomarkers changed significantly in a similar manner as testosterone between the time points (e.g. prostate specific antigen, creatinine and magnesium), whereas seven other markers changed in the inverse manner as testosterone, including sexual hormone-binding globulin, urea, aspartate aminotransferase and alanine aminotransferase. Most of our results were supported by data from other studies. The designed controlled human model yielded changes in known biomarkers suggesting that low testosterone has a negative effect on health in young healthy men.
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| 5. |
- Sonesson, Annika, et al.
(author)
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Determination of serum amyloid P component in seminal plasma and correlations with serum hormone levels in young, healthy men.
- 2011
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In: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 1502-7686 .- 0036-5513. ; 71:7, s. 569-575
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Journal article (peer-reviewed)abstract
- Abstract Serum amyloid P component (SAP) belongs to the pentraxin family of proteins. SAP is evolutionary conserved, and involved in amyloidosis, innate immunity, inflammation, and apoptosis. We have previously described SAP in the male reproductive tract, where it occurs in seminal fluid, on spermatozoa, and in epididymal, seminal vesicle, and prostate tissue. In the present investigation, our aim was to characterize SAP in male reproduction. In short, we developed and evaluated an immunoassay, analysed the concentration of SAP in seminal plasma and serum in samples from healthy men (N = 203), and studied hormonal regulation. SAP in seminal plasma showed a positively skewed distribution and a median concentration of 1.01 mg/L (inter quartile range [IQR] 0.56-1.65 mg/L). SAP in serum had a Gaussian distribution and a median concentration of 40.5 mg/L (IQR 34.2-49.2 mg/L). Furthermore, SAP concentrations in seminal plasma were not correlated with serum concentrations of SAP, testosterone, sex hormone-binding globulin (SHBG), the testosterone/SHBG ratio, inhibin B, or estradiol. Only a weak negative correlation was found between seminal plasma SAP and serum levels of follicle-stimulating hormone (FSH) (Spearman's rho -0.159; p = 0.023) and luteinizing hormone (LH) (Spearman's rho -0.162; p = 0.021). In conclusion, all men investigated had measurable SAP levels in seminal plasma and in serum. SAP concentrations were 40 times lower in seminal fluid than in serum, and there was no correlation between those two variables. It seems that hormonal regulation is not the major pathway regulating seminal plasma SAP, and seminal plasma SAP and serum SAP are not co-regulated.
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