Purpose: Testosterone analysis in hair allows for retrospective evaluation of endogenous testosterone concentrations, but studies devoted to investigating confounders in hair testosterone analysis have hitherto been scarce. The current study examined the stability of testosterone concentrations between two hair samples collected three months apart and investigated two potential confounding factors: natural hair colour and cosmetic hair treatments.

Methods: Testosterone was analysed with an in-house radioimmunoassay with a limit of detection adequate for the purpose.

Results: The testosterone concentrations from the two samplings, at baseline and three months later, had an intra-individual correlation of moderate strength (rho = 0.378, p<0.001, n = 146). Hair treatment, such as colouring or bleaching, seemed to increase testosterone concentrations (p = 0.051, n = 191, and in a paired analysis in a subset of the cohort p = 0.005, n = 24), while no effect of natural colour in untreated hair (p = 0.133) could be detected.

Conclusion: The current results suggest that cosmetic hair treatments need to be considered in hair testosterone analyses and demonstrate the utility of a radioimmunoassay to reliably measure testosterone concentrations in small hair samples in women.

Introduction: Cardiovascular events and infections are common in the acute phase after stroke. It has been suggested that these complications may be associated with excessive sympathetic activation due to the stroke, and that beta-adrenergic antagonists (beta-blockers) therefore may be beneficial. Aim: The aim of the current meta-analysis was to investigate the association between beta-blocker treatment in acute stroke and the three outcomes: mortality, functional outcome and post-stroke infections. Methods: A literature search was performed using the keywords stroke, cerebrovascular disorders, adrenergic beta-antagonists, treatment outcome and mortality. Randomized clinical trials and observational studies were eligible for data extraction. Heterogeneity was investigated using I-2 statistics. Random effect model was used when heterogeneity presented among studies; otherwise, a fixed-effect model was used. Publication bias was assessed using Eggers test and by visually inspecting funnel plots. Results: A total of 20 studies were eligible for at least one of the three outcomes. Two of the included studies were randomized controlled trials and 18 were observational studies. Quality assessments indicated that the risk of bias was moderate. The meta-analysis found no significant association between treatment with beta-blockers and any of the three outcomes. The studies analyzed for the outcomes mortality and infection were heterogeneous, while studies analyzed for functional outcome were homogeneous. The articles analyzed for mortality showed signs of publication bias. Conclusion: The lack of significant effects in the current meta-analysis, comprising more than 100,000 patients, does not support the proposed beneficial effects of beta-blockers in the acute phase of stroke.

Background: Stroke is among the leading causes of death and disability. Although intense research efforts have provided promising treatment options in animals, most clinical trials in humans have failed and the therapeutic options are few. Several factors have been suggested to explain this translational difficulty, particularly concerning methodology and study design. Consistent infarcts and low mortality might be desirable in some, but not all, studies. Here, we aimed to investigate whether the use of laser Doppler flowmetry (LDF) and the occlusion time (60 vs. 45 min) affected outcome variability and mortality in a rat stroke model. Eighty ovariectomized female Wistar rats were subjected to ischemic stroke using intraluminal filament middle cerebral artery occlusion with or without LDF and with occlusion times of 45 or 60 min. Outcome was evaluated by triphenyl tetrazolium chloride staining of brain slices to measure infarct size and a modified sticky tape test. Results: Neither LDF nor occlusion times of 45 versus 60 min significantly affected mortality, outcome variability or outcome severity. Conclusions: Due to the unexpectedly high mortality and variability the statistical power was very low and thus the results were inconclusive.

Background: In the absence of active management, the stroke risk after a transient ischemic attack (TIA) may be high. Almost 10 years ago, the results of the EXPRESS and SOS-TIA studies called for a more rapid management of TIA patients. The purpose of this study was to investigate the other stroke risks in the longer term, after the implementation of a more active approach to TIA. We also wanted to assess the predictive value of the ABCD2 score in this context. Methods: Riksstroke is the national stroke registry in Sweden. Data from Riksstrokes TIA module, and the national cause-of-death register, for the years 2011 and 2012 were used in this study. Stroke occurrence was monitored via Riksstroke. Coxs regression was used for risk evaluation. The predictive value of the ABCD2 score was assessed by calculating the area under the receiver operating characteristics curve. Results: A total of 15,068 TIA episodes occurred in 14,102 patients. The follow-up time varied between 0 and 819 days, with an average of 417 days. The mortality for all TIA patients during the follow-up time was 7.1%. Of the unique patients, 545 had one or more strokes (3.9%), corresponding to 34 events per 1,000 person years. Significant risk factors for stroke were: age, previous TIA, atrial fibrillation (AF), oral anticoagulant (OAC) treatment, hypertension treatment, and the ABCD2 items speech impairment, unilateral weakness, and diabetes mellitus. The ABCD2 score correlated with a subsequent stroke, but its predictive value was low. Conclusion: The risk of stroke is low after the acute phase of a TIA, probably lower than in previous studies. This may be due to better secondary prevention in recent years. Several risk factors predict stroke, notably hypertensive treatment, which may be inadequate; and AF, where OACs may be under-used. It is difficult to identify the role of the ABCD2 score in clinical practice. (C) 2016 S. Karger AG, Basel

Background: Growing evidence indicates that elevated body temperature after stroke is associated with unfavorable outcome. The aim of the current study was to investigate which factors predict temperature elevation within 48 h of stroke onset. Specifically, we hypothesized that temperature elevation would be associated with stroke symptom severity and that hemorrhagic stroke would cause a more pronounced temperature increase compared to ischemic stroke. Methods: The medical records of 400 stroke patients were retrospectively reviewed. Multiple linear regression analysis was used to determine which factors were associated with elevated body temperature. Results: Several factors were significantly associated with peak body temperature (the highest recorded body temperature) within 48 h of stroke onset: stroke severity measured by the National Institutes of Health Stroke Scale (NIHSS) (regression coefficient; (RC) 0.022), female gender (RC 0.157), tympanic/non-rectal temperature reading (RC -0.265), swallowing difficulties (RC 0.335), intubation (RC 0.470), antipyretic treatment (RC 0.563), and C-reactive protein amp;gt; 50 or signs of infection at admission (RC 0.298). Contrary to our expectations, patients with intracerebral hemorrhage did not have higher peak body temperatures than patients with ischemic stroke. Conclusions: In conclusion, temperature elevation within the first 48 h of stroke onset is common, can be partially predicted using information at admission and is strongly associated with stroke severity. The strong association with stroke severity may, at least partly, explain the previously described association between post-stroke temperature elevation and unfavorable outcome.

BACKGROUND:

Cortisol concentrations in plasma display a circadian rhythm in adults and children older than one year. Earlier studies report divergent results regarding when cortisol circadian rhythm is established. The present study aims to investigate at what age infants develop a circadian rhythm, as well as the possible influences of behavioral regularity and daily life trauma on when the rhythm is established. Furthermore, we determine age-related reference intervals for cortisol concentrations in saliva during the first year of life.

METHODS:

130 healthy full-term infants were included in a prospective, longitudinal study with saliva sampling on two consecutive days, in the morning (07:30-09:30), noon (10:00-12:00) and evening (19:30-21:30), each month from birth until the infant was twelve months old. Information about development of behavioral regularity and potential exposure to trauma was obtained from the parents through the Baby Behavior Questionnaire and the Life Incidence of Traumatic Events checklist.

RESULTS:

A significant group-level circadian rhythm of salivary cortisol secretion was established at one month, and remained throughout the first year of life, although there was considerable individual variability. No correlation was found between development of cortisol circadian rhythm and the results from either the Baby Behavior Questionnaire or the Life Incidence of Traumatic Events checklist. The study presents salivary cortisol reference intervals for infants during the first twelve months of life.

CONCLUSIONS:

Cortisol circadian rhythm in infants is already established by one month of age, earlier than previous studies have shown. The current study also provides first year age-related reference intervals for salivary cortisol levels in healthy, full-term infants.

The majority of the numerous animal studies of the effects of estrogens on cerebral ischemia have reported neuroprotective results, but a few have shown increased damage. Differences in hormone administration methods, resulting in highly different 17 beta-estradiol levels, may explain the discrepancies in previously reported effects. The objective of the present study was to test the hypothesis that it is the delivered dose per se, and not the route and method of administration, that determines the effect, and that high doses are damaging while lower doses are protective. One hundred and twenty ovariectomized female Wistar rats (n = 40 per group) were randomized into three groups, subcutaneously administered different doses of 17 beta-estradiol and subjected to transient middle cerebral artery occlusion. The modified sticky tape test was performed after 24 h and the rats were subsequently sacrificed for infarct size measurements. In contrast to our hypothesis, a significant negative correlation between 17 beta-estradiol dose and infarct size was found (p = 0.018). Thus, no support was found for the hypothesis that 17 beta-estradiol can be both neuroprotective and neurotoxic merely depending on dose. In fact, on the contrary, the findings indicate that the higher the dose of 17 beta-estradiol, the smaller the infarct.

The majority of the numerous animal studies of the effects of estrogens on cerebral ischemia have reported neuroprotective results, but a few have shown increased damage. Differences in hormone administration methods, resulting in highly different 17β-estradiol levels, may explain the discrepancies in previously reported effects. The objective of the present study was to test the hypothesis that it is the delivered dose per se, and not the route and method of administration, that determines the effect, and that high doses are damaging while lower doses are protective. One hundred and twenty ovariectomized female Wistar rats (n=40 per group) were randomized into three groups, subcutaneously administered different doses of 17β-estradiol and subjected to transient middle cerebral artery occlusion. The modifi ed sticky tape test was performed after 24 h and the rats were subsequently sacrifi ced for infarct size measurements. In contrast to our hypothesis, a signifi cant negative correlation between 17β-estradiol dose and infarct size was found (p=0.018). Thus, no support was found for the hypothesis that 17β-estradiol can be both neuroprotective and neurotoxic merely depending on dose. In fact, on the contrary, the fi ndings indicate that the higher the dose of 17β-estradiol, the smaller the infarct.

Although hundreds of promising substances have been tested in clinical trials, thrombolysis currently remains the only specifi c pharmacological treatment for ischemic stroke. Poor quality, e.g. low statistical power, in the preclinical studies has been suggested to play an important role in these failures. Therefore, it would be attractive to use animal models optimized to minimize unnecessary mortality and outcome variability, or at least to be able to power studies more exactly by predicting variability and mortality given a certain experimental setup. The possible combinations of methodological parameters are innumerous, and an experimental comparison of them all is therefore not feasible. As an alternative approach, we extracted data from 334 experimental mouse stroke articles and, using a hypothesis-driven meta-analysis, investigated the method parameters’ impact on infarct size variability and mortality. The use of Swiss and C57BL6 mice as well as permanent occlusion of the middle cerebral artery rendered the lowest variability of the infarct size while the emboli methods increased variability. The use of Swiss mice increased mortality. Our study offers guidance for researchers striving to optimize mouse stroke models.

Background Cortisol concentrations in plasma display a circadian rhythm in adults and children older than one year. Earlier studies report divergent results regarding when cortisol circadian rhythm is established. The present study aims to investigate at what age infants develop a circadian rhythm, as well as the possible influences of behavioral regularity and daily life trauma on when the rhythm is established. Furthermore, we determine age-related reference intervals for cortisol concentrations in saliva during the first year of life. Methods 130 healthy full-term infants were included in a prospective, longitudinal study with saliva sampling on two consecutive days, in the morning (07:30-09:30), noon (10:00-12:00) and evening (19:30-21:30), each month from birth until the infant was twelve months old. Information about development of behavioral regularity and potential exposure to trauma was obtained from the parents through the Baby Behavior Questionnaire and the Life Incidence of Traumatic Events checklist. Results A significant group-level circadian rhythm of salivary cortisol secretion was established at one month, and remained throughout the first year of life, although there was considerable individual variability. No correlation was found between development of cortisol circadian rhythm and the results from either the Baby Behavior Questionnaire or the Life Incidence of Traumatic Events checklist. The study presents salivary cortisol reference intervals for infants during the first twelve months of life. Conclusions Cortisol circadian rhythm in infants is already established by one month of age, earlier than previous studies have shown. The current study also provides first year age-related reference intervals for salivary cortisol levels in healthy, full-term infants.