Lack of association in acne and salivary testosterone

The pathogenesis of acne vulgaris has only been partially elucidated. Various hormones, especially androgens, are likely to play a role, but results of studies are still inconclusive. The objective of the current study was to investigate whether day to day variation in salivary testosterone correlates with acne in males. Saliva samples were collected for 120 consecutive days from each of the 40 males. Salivary testosterone concentrations were measured by enzyme-linked immunosorbent assay (ELISA). Facial acne lesions were assessed on a daily basis by photography by the participating males. Potential confounders’ (sexual intercourse, masturbation, physical exercise and disease) were also registered every day by the participants. A significant but weak association between salivary testosterone and acne was found (n = 4602, r = 0.031, P = 0.034). Elevated testosterone concentrations were associated with an increase in acne, but when testosterone concentrations were above twice the individual average, acne lesions paradoxically decreased. The current results indicate that daily fluctuations in salivary testosterone levels in males are associated with acne patterns, but the weak correlation suggests that the effect is too small to be of clinical significance. The analysis in the current study was complicated by a large number of days on which the participants had no acne, as well as the seemingly non-monotonic relation between testosterone and acne. This may indicate that the actual relation is stronger than concluded here

Original publication:

Order of magnitude differences between methods for maintaining physiological 17βestradiol concentrations in ovariectomized rat

Substantial discrepancies in 17β-estradiol concentrations obtained with three different commercial direct radioimmunoassay kits in rat sera

The extensive use of estrogen for contraception and amelioration of post-menopausal symptoms has made it the subject of substantial recent research efforts. Ovariectomized (ovx) rats treated with exogenous ovarial hormones constitute important tools in the investigation of the effects and mechanisms of estrogen actions. The crucial need to control and to monitor plasma levels of 17β-estradiol calls for accurate, precise and robust assay methods. The performance of direct radioimmunoassays (RIAs) for measurement of 17β-estradiol has previously been reported for human samples, but – to our knowledge – not for rat samples. In the current study, 552 serum samples from ovx, native and hormone treated rats were used to compare the performance of three commercially manufactured direct RIAs from the companies DPC (Siemens Healthcare Diagnostics Inc., formerly Diagnostic Products Corporation), DSL (Diagnostic Systems Labs) and MPB (MP Biomedicals, formerly ICN Biomedicals). Substantial differences in results between the three assay methods were found when measuring serum 17β-estradiol concentrations. The following formulas, describing the relation between the different methods’ results, were obtained using weighted Deming’s orthogonal regression (all regression formulae in the abstract are based on pg/mL): DSL= 0.43*DPC+12.3, MPB= 2.1*DPC+84.7 and DSL= 4.8*MPB+22.2. Furthermore, a preceding diethyl ether extraction step of the serum appears to impair the RIAs’ performances in the present samples: DPCex= 0.39*DPCunex+0.76, DSLex= 0.32*DSLunex-1.7 and MPBex= 0.22*MPBunex+1.4.Original publication: Jakob O. Ström, Annette Theodorsson and Elvar Theodorsson, Substantial discrepancies in 17β-estradiol concentrations obtained with three different commercial direct radioimmunoassay kits in rat sera, 2008, Scandinavian Journal of Clinical and Laboratory Investigation.http://dx.doi.org/10.1080/00365510802254638. Copyright © Taylor & Francis Group, an informa busines

Testosterone-like immunoreactivity in hair measured in minute sample amounts - a competitive radioimmunoassay with an adequate limit of detection

The concentrations of testosterone deposited in hair during hair growth may provide a retrospective reflection of the concentrations of bioactive testosterone in plasma. The objective of this study was to develop a radioimmunoassay with a sufficiently low limit of detection to measure the testosterone-like immunoreactivity in smaller hair samples (5 mg) than used in earlier studies, and to compare three different extraction procedures. The competitive radioimmunoassay consisted of a polyclonal antiserum (immunogen testosterone-7 alpha-BSA) and a radioligand synthesised from testosterone-3-CMO-histamine. The within-assay and total coefficients of variation in the working range was 3% and 4.5%, respectively. The limit of detection was 0.87 pg/mL, which is equivalent to 0.12 pg/mg testosterone in 5 mg of hair. The concentration of testosterone-like immunoreactivity in hair samples was 1.23 (SD 0.47) pg/mg in women and 2.67 (SD 0.58) pg/mg in men (pulverised hair). Significantly improved precision was found when pulverised hair was used compared to non-pulverised hair. Our data indicate that pulverisation of the hair prior to hormone extraction is crucial. Detection limits fit for the intended purpose are achievable with 5 mg samples of hair.Funding Agencies|County Council of Ostergotland</p

Order of magnitude differences between methods for maintaining physiological 17β-estradiol concentrations in ovariectomized rats

The use of animal, especially rat, models, is crucial for elucidating the biological effects and mechanisms of the widely used hormone 17β-estradiol. Unfortunately there is a lack of consensus on optimal means of obtaining and maintaining physiological 17β-estradiol concentrations in plasma. This may be the reason for varying results in several studies including the disagreement on whether 17β-estradiol is neuroprotective or not. Very few studies have been devoted to investigating the characteristics and biological relevance of different methods of 17β-estradiol administration. We therefore ovariectomized 75 Sprague-Dawley rats and, following a 2 weeks wash-out period, administered 17β-estradiol using three different methods; daily injections (10 µg 17β-estradiol/kg), slow-release pellets (0.25 mg 60 day-release pellets, 0.10 mg 90 day-release pellets) and silastic capsules (with/without wash-out periods) (silastic laboratory tubing, inner/outer diameter: 1.575/3.175 mm, filled with 20 mm columns of 180 µg 17β-estradiol/mL sesame oil). Further 45 animals were used as ovariectomized and native controls, studied in different parts of the estrous cycle. Silastic capsules produced concentrations of 17β-estradiol within the physiological range for 4-5 weeks independent of whether a prior wash-out period was included or not. The slow-release pellets, irrespective of dose or release period, resulted in initial concentrations which were an order of magnitude above physiological concentrations during the first two weeks followed by a substantial decrease. Daily injections resulted in increasing 17β-estradiol concentrations, however within physiological levels. Silastic capsules are conveniently manufactured and used, and are superior to pellets and injections in reliably producing long-term 17β-estradiol concentrations within the physiological range.Original publication: Jakob O. Ström, Elvar Theodorsson and Annette Theodorsson, Order of magnitude differences between methods for maintaining physiological 17β-estradiol concentrations in ovariectomized rats, 2008, Scandinavian Journal of Clinical and Laboratory Investigation.http://dx.doi.org/10.1080/00365510802409703. Copyright © Taylor & Francis Group, an informa busines

Substantial discrepancies in 17β-estradiol concentrations obtained with three different commercial direct radioimmunoassay kits in rat sera

The extensive use of estrogen for contraception and amelioration of post-menopausal symptoms has made it the subject of substantial recent research efforts. Ovariectomized (ovx) rats treated with exogenous ovarial hormones constitute important tools in the investigation of the effects and mechanisms of estrogen actions. The crucial need to control and to monitor plasma levels of 17β-estradiol calls for accurate, precise and robust assay methods. The performance of direct radioimmunoassays (RIAs) for measurement of 17β-estradiol has previously been reported for human samples, but – to our knowledge – not for rat samples. In the current study, 552 serum samples from ovx, native and hormone treated rats were used to compare the performance of three commercially manufactured direct RIAs from the companies DPC (Siemens Healthcare Diagnostics Inc., formerly Diagnostic Products Corporation), DSL (Diagnostic Systems Labs) and MPB (MP Biomedicals, formerly ICN Biomedicals). Substantial differences in results between the three assay methods were found when measuring serum 17β-estradiol concentrations. The following formulas, describing the relation between the different methods’ results, were obtained using weighted Deming’s orthogonal regression (all regression formulae in the abstract are based on pg/mL): DSL= 0.43*DPC+12.3, MPB= 2.1*DPC+84.7 and DSL= 4.8*MPB+22.2. Furthermore, a preceding diethyl ether extraction step of the serum appears to impair the RIAs’ performances in the present samples: DPCex= 0.39*DPCunex+0.76, DSLex= 0.32*DSLunex-1.7 and MPBex= 0.22*MPBunex+1.4.Original publication: Jakob O. Ström, Annette Theodorsson and Elvar Theodorsson, Substantial discrepancies in 17β-estradiol concentrations obtained with three different commercial direct radioimmunoassay kits in rat sera, 2008, Scandinavian Journal of Clinical and Laboratory Investigation.http://dx.doi.org/10.1080/00365510802254638. Copyright © Taylor & Francis Group, an informa busines