Popularity of natural-based preparations supporting the sexual potency significantly increased in recent years, which also led to the increase of illegal use of phosphodiesterase type 5 inhibitor (PDE-5) in sexual performance enhancement products. In this study, a rapid U-HPLC‒HRMS/MS method has been developed to simultaneously determine 59 PDE-5 inhibitors and their analogues. Within the development of sensitive method for analysis of 59 PDE-5 inhibitors and their analogues, both sample preparation procedure, as well as separation / detection conditions have been optimized. Extraction efficiency of particular extraction solvents, influence of different mobile phase additives on target analytes separation, as well as impact of various settings of mass analyzer on sensitivity of detection were examined. Data were collected in the 'full MS/data dependent MS/MS' acquisition mode (full MS-dd-MS/MS). Before the U-HPLC‒HRMS/MS method was used for analysis of real samples, proper validation had been conducted. The precision of the method expressed as the relative standard deviation (RSD) was ≤4.2% and ≤5.2% at spiking concentrations 5 μg/g and 0.25 μg/g, respectively. The limits of quantification were in the range 0.25 - 0.05 μg/g and the recovery ranged between 71 and 90%. The optimized method was successfully applied for analysis of 64 real samples, and 10 of them were proved to contain both registered or unregistered synthetic PDE-5 inhibitors. Additionally, the acquired U-HPLC‒HRMS/MS fingerprints were demonstrated to serve as an efficient tool for revealing of other type of possible fraud in products labeling. Retrospective mining of markers of herbs declared on dietary supplements packaging allowed to assess the trueness / untruth in the declaration of medical herbs composition.
This study estimates the causal effect of working hours on health. We deal with the endogeneity of working hours through instrumental variables techniques. In particular, we exploit exogenous variation in working hours from statutory workweek regulations in the German public sector as an instrumental variable. Using panel data, we run two-stage least squares regressions controlling for individual-specific unobserved heterogeneity. We find adverse consequences of increasing working hours on subjective and several objective health measures. The effects are mainly driven by women and parents of minor children who generally face heavier constraints in organizing their workweek.
We examine how a paid parental leave reform causally affected families' living arrangements. The German reform we examine replaced a means-tested benefit with a universal transfer paid out for a shorter period. Combining a regression discontinuity with a difference-in-differences design, we find that the reform increased the probability that a newborn lives with non-married cohabiting parents. This effect results from a reduced risk of single parenthood among women who gained from the reform. We reject the economic independence hypothesis and argue that the reform effects for those who benefited from the reform are consistent with hypotheses related to the improved financial situation of new mothers after the reform and increased paternal involvement in childcare.
Residents’ preferences are one of the factors in deciding how brownfields should be revitalized. We compare the views of residents in a city with many brownfields (Karvina) with those in a city with only few brownfields (Ceske Budějovice). We assessed the preferences of residents for four global regeneration alternatives (refurbishment, demolition, open space, (re)development) in three different areas of a city (city centre, inner city, city outskirts). A one percent population sample of two post-socialistic cities in the Czech Republic, was used for the comparison. Positive preferences towards brownfield regeneration were confirmed. We found spatial differences in preferences between refurbishment and demolition of brownfields in each city area: demolition was preferred for inner city brownfields whereas refurbishment was preferred in the city centre and outskirts. Differences were also identified between the two cities: residents of the brownfield rich city preferred demolition, whereas residents of the city with few brownfields preferred refurbishment. Creating new public open space, for residents′ recreation, was given a lower importance within the city centre and a higher significance in outskirts. With the support of a combined ANOVA model, significant differences in residents’ preferences were found for distinct types of regeneration with regards to the cities’ character, the location of brownfields within the city and residents′ proximity.
A wide variety of interventions exists in physical therapy (PT), but knowledge about their use across different geographical regions is limited. This study investigated the use of PT interventions in people with multiple sclerosis (MS) across Europe. It aimed to determine whether regions differ in applying interventions, and explore whether factors other than regions play a role in their use.
Reduced activity of protein phosphatase 2 A (PP2A) is a common feature in Alzheimer's disease (AD) and non-AD tauopathies. The administration of okadaic acid (OKA), a potent PP2A and PP1 inhibitor, is a common research tool for inducing AD-like alterations such as tau hyperphosphorylation and cognitive decline. Recently, we showed that OKA increases cerebrospinal fluid (CSF) glutamate levels, which was strongly correlated with cognitive decline. Also, we demonstrated that memantine (MN), a glutamatergic NMDAR channel blocker, was capable of preventing the increase in CSF glutamate levels and cognitive decline. Here, we aimed to analyze whether the protective effects of MN involve intrinsic astrocytic properties, particularly related to glutamate uptake and astrocytic reactivity - indexed by the expression of S100B and glial fibrillary acidic protein (GFAP). Rats received intraperitoneal injections of MN or saline over 3 consecutive days before receiving intrahippocampal infusion of OKA or saline. Afterward, they were submitted to behavioral tasks and then, euthanatized for neurochemical analysis. Here, we showed that the neuroprotective effects of MN in response to OKA neurotoxicity involve astrocytic activation. MN decreased glutamate uptake in the hippocampus and increased the release of S100B protein in the CSF in response to OKA neurotoxicity, which indicates a possible neurons-astrocyte coupling protective mechanism. These findings shed light on astrocytes as potential targets for treating neurological disorders associated with decreased PP2A activity.
Several works have demonstrated that status epilepticus (SE) induced-neurodegeneration appears to involve an overactivation of N-methyl-d-aspartate receptors and treatment with high-affinity NMDAR antagonists is neuroprotective against this brain damage. However, these compounds display undesirable side effects for patients since they block physiological NMDA receptor dependent-activity. In this context, memantine (MN), a well tolerable low-affinity NMDAR channel blocker, will be a promising alternative, since it does not compromise the physiological role of NMDA receptors on synaptic transmission. The aim of the present study was to investigate if MN could attenuate seizure severity and neuronal cell death caused by SE induced early in life. Wistar rats (15 days old; n = 6-8 per group) received memantine (20 mg/kg i.p.) in six different treatments: 6 and 3 h before SE onset; concomitant with pilocarpine; 15min and 1h after SE onset; and four consecutive administrations (15 min, 6 h, 12 h, and 18 h) after pilocarpine injection. Neurodegeneration was quantified by fluoro-jade C staining. Treatment with memantine increase latency to SE onset only in groups treated 3 h before or concomitant with pilocarpine. In CA1 hippocampal subfield, memantine significantly reduced neurodegeneration at the following times: 3 h prior SE-onset, concomitant with pilocarpine, and 15 min after pilocarpine injection. For amygdala and thalamus, all post-SE onset treatments were able to decrease neurodegeneration. In conclusion, the present study showed that MN was neuroprotective against SE-induced neuronal death and this neuroprotection appears to be time- and region-dependent.