One-minute through test to distinguish lower respiratory infection by analysis of sputum; exploring the mechanisms.

Objective: Cough and fever are the initial symptoms of lower respiratory infection. Severe cases might be fatal. Therefore, particularly in the non-equipped centers, the lack of diagnostic methods to identify the severe cases has resulted in overconsumption of antibiotics.

Male Testosterone Does Not Adapt to the Partner's Menstrual Cycle.

Background: It has not yet been established whether men in heterosexual relationships adapt their hormone levels to their female partner's menstrual cycle to allocate reproductive resources to the period when the female is actually fertile.

Aim: This prospective observational study tested the hypothesis that some males have peaks in testosterone or acne (a possible biomarker for androgen activity) near their partners' ovulation, whereas other males display the opposite pattern.

Methods: 48 couples supplied menstrual cycle data, male salivary samples, and a protocol of daily activities for 120 days.

Effect of laser Doppler flowmetry and occlusion time on outcome variability and mortality in rat middle cerebral artery occlusion: inconclusive results.

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.

Development of salivary cortisol circadian rhythm in preterm infants.

Objectives: To investigate at what age preterm infants develop a salivary cortisol circadian rhythm and identify whether it is dependent on gestational age and/or postnatal age. To evaluate whether salivary cortisol circadian rhythm development is related to behavioral regularity. To elucidate salivary cortisol levels in preterm infants during the first year of life.

Method parameters' impact on mortality and variability in mouse stroke experiments: a meta-analysis.

Although hundreds of promising substances have been tested in clinical trials, thrombolysis currently remains the only specific pharmacological treatment for ischemic stroke. Poor quality, e.g.

Effects of high and low 17β-estradiol doses on focal cerebral ischemia in rats.

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.

Elevated body swing test after focal cerebral ischemia in rodents: methodological considerations.

Background: The elevated body swing test (EBST) is a behavioral test used to evaluate experimental stroke in rodents. The basic idea is that when the animal is suspended vertically by the tail, it will swing its head laterally to the left or right depending on lesion side. In a previous study from our lab using the EBST after middle cerebral artery occlusion (MCAo), rats swung contralateral to the infarct day 1 post-MCAo, but ipsilateral day 3 post-MCAo.

Development of Salivary Cortisol Circadian Rhythm and Reference Intervals in Full-Term Infants.

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.

DNA Methylation Inhibitor Zebularine Confers Stroke Protection in Ischemic Rats.

5-Aza-deoxycytidine (5-aza-dC) confers neuroprotection in ischemic mice by inhibiting DNA methylation. Zebularine is another DNA methylation inhibitor, less toxic and more stable in aqueous solutions and, therefore more biologically suitable. We investigated Zebularine's effects on brain ischemia in a rat middle cerebral artery occlusion (MCAo) model in order to elucidate its therapeutic potential.

Effects of high and low 17β-estradiol doses on focal cerebral ischemia: negative results.

The reasons why some animal studies indicate that estrogens increase focal cerebral ischemic damage while others show estrogen-induced neuroprotection has hitherto not been fully elucidated. Recent evidence indicates that discrepancies in hormone administration paradigms, resulting in highly different serum hormone concentrations, may account for the dichotomy. The current study aimed to test this hypothesis.

Method parameters' impact on mortality and variability in rat stroke experiments: a meta-analysis.

Background: Even though more than 600 stroke treatments have been shown effective in preclinical studies, clinically proven treatment alternatives for cerebral infarction remain scarce. Amongst the reasons for the discrepancy may be methodological shortcomings, such as high mortality and outcome variability, in the preclinical studies. A common approach in animal stroke experiments is that A) focal cerebral ischemia is inflicted, B) some type of treatment is administered and C) the infarct sizes are assessed.

Ovariectomy and 17β-estradiol replacement in rats and mice: a visual demonstration.

Estrogens are a family of female sexual hormones with an exceptionally wide spectrum of effects. When rats and mice are used in estrogen research they are commonly ovariectomized in order to ablate the rapidly cycling hormone production, replacing the 17β-estradiol exogenously. There is, however, lack of consensus regarding how the hormone should be administered to obtain physiological serum concentrations.

CSF-biomarkers in Olympic boxing: diagnosis and effects of repetitive head trauma.

Background: Sports-related head trauma is common but still there is no established laboratory test used in the diagnostics of minimal or mild traumatic brain injuries. Further the effects of recurrent head trauma on brain injury markers are unknown. The purpose of this study was to investigate the relationship between Olympic (amateur) boxing and cerebrospinal fluid (CSF) brain injury biomarkers.

The female menstrual cycle does not influence testosterone concentrations in male partners.

Background: The time of ovulation has since long been believed to be concealed to male heterosexual partners. Recent studies have, however, called for revision of this notion. For example, male testosterone concentrations have been shown to increase in response to olfactory ovulation cues, which could be biologically relevant by increasing sexual drive and aggressiveness.

Changes in galanin and GalR1 gene expression in discrete brain regions after transient occlusion of the middle cerebral artery in female rats.

Injury to neurons results in up-regulation of galanin in some central and peripheral systems, and it has been suggested that this neuropeptide may play a protective and trophic role, primarily mediated by galanin receptor 2 (GalR2). The objective of the present study was to investigate galanin, GalR1, GalR2 and GalR3 gene expression in the female rat brain 7 days after a 60-min unilateral occlusion of the middle cerebral artery followed by reperfusion. Quantitative real-time PCR was employed in punch-biopsies from the locus coeruleus, somatosensory cortex and dorsal hippocampal formation, including sham-operated rats as controls.

Methods for 17β-oestradiol administration to rats.

Several studies indicate that the beneficial or harmful effects of oestrogens in stroke are dose-dependent. Rats are amongst the most frequently used animals in these studies, which calls for thoroughly validated methods for administering 17β-oestradiol to rats. In an earlier study we characterised three different administration methods for 17β-oestradiol over 42 days.

Mechanisms of estrogens' dose-dependent neuroprotective and neurodamaging effects in experimental models of cerebral ischemia.

Ever since the hypothesis was put forward that estrogens could protect against cerebral ischemia, numerous studies have investigated the mechanisms of their effects. Despite initial studies showing ameliorating effects, later trials in both humans and animals have yielded contrasting results regarding the fundamental issue of whether estrogens are neuroprotective or neurodamaging. Therefore, investigations of the possible mechanisms of estrogen actions in brain ischemia have been difficult to assess.

Hormesis and Female Sex Hormones.

Hormone replacement after menopause has in recent years been the subject of intense scientific debate and public interest and has sparked intense research efforts into the biological effects of estrogens and progestagens. However, there are reasons to believe that the doses used and plasma concentrations produced in a large number of studies casts doubt on important aspects of their validity. The concept of hormesis states that a substance can have diametrically different effects depending on the concentration.

Effects of intracerebroventricular galanin or a galanin receptor 2/3 agonist on the lesion induced by transient occlusion of the middle cerebral artery in female rats.

Several studies have shown that injury to the central and peripheral nervous system can increase expression of galanin, a 29 amino acid neuropeptide. Moreover, there is evidence that galanin, especially through its galanin receptor 2 (GalR2) receptor, plays a neuroprotective role in different injury models. However, direct studies of a possible neuroprotective effect of galanin in experimental stroke models are lacking.

Different methods for administering 17beta-estradiol to ovariectomized rats result in opposite effects on ischemic brain damage.

Background: Numerous stroke studies have controversially shown estrogens to be either neuroprotective or neurodamaging. The discordant results observed in rat brain ischemia models may be a consequence of discrepancies in estrogen administration modes resulting in plasma concentration profiles far from those intended. To test this hypothesis we reproduced in detail and extended an earlier study from our lab using a different mode of 17beta-estradiol administration; home-made silastic capsules instead of commercial slow-release 17beta-estradiol pellets.

Dose-related neuroprotective versus neurodamaging effects of estrogens in rat cerebral ischemia: a systematic analysis.

Numerous studies of the effects of estrogens for stroke prevention have yielded conflicting results in human and animal studies alike. We present a systematical analysis of study design and methodological differences between 66 studies where estrogens' impact on ischemic brain damage in rat models has been investigated, providing evidence that the differences in results may be explained by high estrogen doses produced by slow-release pellets. These pellets have been used in all studies showing increased neurologic damage because of estrogens.

Order of magnitude differences between methods for maintaining physiological 17beta-oestradiol concentrations in ovariectomized rats.

The use of animal models, especially the rat, is crucial for elucidating the biological effects and mechanisms of the widely used hormone 17beta-oestradiol. Unfortunately, there is a lack of consensus on optimal means of obtaining and maintaining physiological 17beta-oestradiol concentrations in plasma and this may be the reason for the varying results in several studies, including the disagreement on whether 17beta-oestradiol is neuroprotective or not. Very few studies have been devoted to investigating the characteristics and biological relevance of different methods of 17beta-oestradiol administration.

Substantial discrepancies in 17beta-oestradiol concentrations obtained with three different commercial direct radioimmunoassay kits in rat sera.

The extensive use of oestrogen for contraception and amelioration of post-menopausal symptoms has made it the subject of substantial recent research efforts, and ovariectomized (ovx) rats treated with exogenous ovarial hormones are important when investigating the effects and mechanisms of oestrogen actions. The crucial need to control and monitor plasma levels of 17beta-oestradiol calls for accurate, precise and robust assay methods. The performance of direct radioimmunoassays (RIAs) in measurement of 17beta-oestradiol has been reported previously for human samples, but to our knowledge not for rat samples.